RIKEN Nishina Center, Wako
Study on atomic nuclei has expanded remarkbly to a broad range of region far from stability since 1980's when a number of accelerator facilities launched scientific programs on rare isotopes and radioactive beams. Today, second-generation accelerator facilities dedicated to research on the rare isotopes and radioactive beams are either operating, under construction, or being proposed. Various types of accelerators are currently used, depending on the goal of research on a variety of unstable nuclei. Based on the recent activity of the radioactive Ion Beam Facility at RIKEN, this presentation provides a world wide overview of the activity on radioactive beams.
LBNL, Berkeley, California
At LBNL in Berkeley, clinical trials were conducted (1975-1992) for treating human cancer using ion beams from the Bevalac and treated about 700 patients with helium-ion and about 300 patients with neon-ion beams.* Clinical trials (1997-2005) at GSI in Darmstadt, Germany used carbon-ion beams to treat about 250 patients. In 1994, NIRS in Chiba, Japan, commissioned its first-in-the-world ion-beam therapy facility, HIMAC, which accelerates ions as heavy as argon nuclei to 800 MeV/nucleon. Following it, several carbon-ion therapy facilities have been, or will be soon, constructed in: Hyogo (2001) and Gunma (2010), Japan; Heidelberg (2009), Marburg (2010) and Kiel (2012), Germany; Pavia (2010), Italy; Lyon (2013), France; Wiener Neustadt (2013), Austria; Shanghai and Lanzhou, China; and Minnesota and California, USA. Technical specifications of these facilities are: ion sources delivering all ion species from proton to carbon, accelerator energy of 430 MeV/n (30-cm range in tissue), beam intensity of about 109 pps (to deliver 1 Gy/min into 1-liter volume), repetition rate of about 0.5 Hz with long spill (for beam scanning), and treatment beam delivery and patient safety systems.
* Castro, JR, "Future research strategy for heavy ion radiotherapy," in Progress in Radio-Oncology (ed. Kogelnik, H.D.), Monduzzi Editore, Italy, 643-648 (1995).
IMP, Lanzhou
Advancement of nuclear physics and high power heavy ion accelerator is always a driving force for persistent development of highly charged ECR ion source. Increasing demands for more intense and higher charge state heavy ion beams have dramatically promoted development of ECR ion source technology and physics. This talk provides an overview of intense highly charged superconducting ECR ion sources built by the world-wide laboratories in the last years. The key technologies, challenges and main issues related to construction and operation of high performance superconducting ECR ion source are reviewed. The latest results of intense highly charged ion beam production from the superconducting ECR ion sources are presented. Future development and the next generation highly charged ECR ion source are discussed.
HMI, Berlin
Charite, Berlin
HZB, Berlin
The ion beam laboratory ISL at the Hahn-Meitner-Institute (HMI) Berlin supplied light and heavy ion beams for research and applications in solid state physics, industry, and medicine. Since 1998, eye tumours are treated with 68 MeV protons in collaboration with the University Hospital Benjamin Franklin, now Charité - Campus Benjamin Franklin. In autumn 2004 the board of directors of the HMI decided to close down ISL at the end of 2006. In December 2006, a cooperation contract between the Charité and the HMI was signed to assure the continuity of the eye tumour therapy, at the moment the only facility in Germany. The accelerator operation will be continued with reduced man-power, requiring changes in the set-up of the accelerators. A new, facile injector for protons is foreseen. Increasing the reliability will be a key issue. The last two years of operation of ISL as a full multi-purpose accelerator will be shown and examples of the research work will be demonstrated. The conversion of a multi-ion, variable energy accelerator to a dedicated accelerator for eye tumour therapy will be discussed.
The Helmholtz-Zentrum Berlin für Materialien und Energie has been formed by the merger of the Hahn-Meitner-Institut Berlin and the Berliner Elektronenspeicherring-Gesellschaft für Synchrotronstrahlung
GSI, Darmstadt
INFN/LNF, Frascati (Roma)
CNAO Foundation, Milan
INFN/LNL, Legnaro (PD)
The Centro Nazionale di Adroterapia Oncologica (CNAO) presently under commissioning in Pavia, Italy, will be the first Italian facility for the treatment of deeply seated tumours with proton and carbon ion beams. The CNAO accelerator comprises a 7 MeV/u injector linac and a 400 MeV/u synchrotron. The 216.8 MHz linac is a copy of the linac at the Heidelberg Ion-Beam Therapy Centre (HIT) and consists of a 400 keV/u 4-rod type RFQ and of a 20 MV IH type drift tube linac. In 2004, a collaboration between CNAO and GSI was established for construction and commissioning of the linac. GSI supervised the manufacturing of the linac and of its technical systems, performed copper-plating, assembly, and tuning (together with IAP Frankfurt), and delivered complete beam diagnostics systems. The RFQ was tested at GSI with proton beams together with the BD systems prior to delivery to CNAO. Installation and commissioning in Pavia were performed in collaboration by CNAO, GSI, and INFN. RFQ and thereafter IH linac were successfully commissioned in two steps in 2009, both with (H3)+ and carbon ion beams. The results of the linac commissioning will be reported as well as a comparison to the HIT linac.
Siemens Med, Erlangen
Siemens DK, Jyllinge
FRIB, East Lansing, Michigan
Siemens has earned three contracts to deliver IONTRIS Particle Therapy accelerator systems* to be operated in Marburg and Kiel, both in Germany, and in Shanghai, China. The accelerator part consists of an injector (7 MeV/u protons and light ions) and a compact synchrotron able to accelerate proton beams up to 250 MeV and carbon ions up to 430 MeV/u. These beams can be slowly extracted and delivered to a choice of fixed-angle horizontal, semi-vertical and vertical beam-ports. An overview of the design will be given and the status of the installation and commissioning work for the first two projects will be shown.
*Particle Therapy is a work in progress and requires country-specific regulatory approval prior to clinical use.
HIT, Heidelberg
Since November, 15th 2009 patients are treated with protons and carbon ions at the Heidelberg Ionbeam Therapy Centre (HIT). The facility - two ion sources, an injector linac and a compact synchrotron - is operated in 24/7-mode with high availability. The HIT beam time schedule is discussed along the statistics automatically generated by the control system. Besides the patient treatment in the first horizontal room beam time is also used to develop enhanced treatment software in the second horizontal room as well as for commissioning the gantry place. Additionally, biophysics studies are served at a separate experimental place. In parallel, an upgrade program for the accelerator is under way: at first a test bench for a third ion source, later on dedicated to He beams, will be used to study several ideas to increase the injector performance. Furthermore operation mechanisms are under progress to control directly the synchrotron dipole and quadrupole fields as well as to regulate the spill structure - the aim of both developments is to form a uniform and extremely stable extracted beam with high duty cycle. An overview on this entire accelerator R&D at HIT will be given.
NIRS, Chiba-shi
AEC, Chiba
Tumor therapy using energetic carbon ions, as provided by the HIMAC, has been performed since June 1994, and more than 5000 patients were treated until now. With the successful clinical results over more than ten years, we are constructing a new treatment facility. The new facility would have three treatment rooms; two of them have both horizontal and vertical fixed-irradiation-ports, and the other has a rotating-gantry-port. For all the ports, a scanning irradiation method is applied. The new facility is constructed in conjunction with the HIMAC, and heavy-ion beams will be provided by the HIMAC accelerators. To fulfill requirements for the scanning irradiation, we proposed multiple-energy operation with the quasi-DC extension of a flat top. With this operation, the beam energy can be successively varied within a single synchrotron-cycle, and therefore no energy degrader or the range shifter is required. The beam acceleration and extraction tests of the multiple-energy operation were successfully made. We will present the development of this operation as well as results of the beam acceleration tests.
Hitachi, Ltd., Energy and Environmental System Laboratory, Hitachi-shi
A compact and high-proton-yield 2.45 GHz microwave ion source has been developed and tested on an AccSys Model PL-7 linac. The source that has an overall diameter of 115 mm uses permanent magnets and iron yokes. Microwave power was fed to a plasma chamber with a double ridged waveguide via a coaxial cable. A pulsed hydrogen ion beam of 45 mA was extracted from a single 5 mm diameter extraction aperture with a proton fraction of >90 % at 30 keV and a hydrogen gas flow rate of 1 sccm. A 7-MeV proton current out of the linac with the source reached up to 16 mApeak, which exceeds its design value of 15 mApeak. Excellent stability of no more than 1.5 % in both the ion source extraction current and the linac output current was also demonstrated in an 8-hour operation test.
JAEA, Ibaraki-ken
Toshiba, Tokyo
JAEA/Kansai, Kyoto
Kyoto ICR, Uji, Kyoto
NIRS, Chiba-shi
The interaction between the high intensity laser and the solid target produces a strong electrostatic proton acceleration field (1 TV/m) with extraordinary small size, contributing to downsizing of the particle accelerator. The proton beam exhibits significant features. having very small source size(~10 um), short pulse duration (~ps) and very low transverse emittance. However it is a diverging beam (half angle of ~10 deg) with wide energy spread of ~100 %. Because of these peculiar characteristics the proton beam attracts many fields for applications including medical applications. To preserve these peculiar characteristics, which are not possessed by those beams from the conventional accelerators, towards the irradiation points, we need to establish a peculiar beam transport line. As the first step, here we report the demonstration of the proto-type laser-driven proton medical accelerator beam line in which we combine the laser-driven proton source with the beam transport technique already established in the conventional accelerator for the purpose of comparison between the data and the particle transport simulation code, PARMILA*.
*Harunori Takeda, 2005, Parmila LANL (LA-UR-98-4478).
JAEA, Ibaraki-ken
We report the demonstrated irradiation effect of laser-accelerated protons on human cancer cells. In-vitro (living) A549 cells are irradiated with a proton beam having a single bunch duration of 20 ns and a beam flux of ~1014cm−2s−1*. The dynamics differ by seven orders of magnitude to the case of a typical Ion Beam Therapy (IBT) operation with a synchrotron: 0.4 s in bunch duration and ~107cm−2s−1 in beam flux. We have measured the yield of DNA double-strand break with phosphorylated histone H2AX immunostaining method and estimated Relative Biological Effectiveness (RBE) of the laser-accelerated protons.
* A. Yogo et al., Appl. Phys. Lett. 94, 181502 (2009).
JAEA, Kyoto
KEK, Ibaraki
RIST, Ibaraki
The concept of a compact ion particle accelerator has become attractive in view of recent progress in laser-driven hadrons acceleration. The Photo Medical Research Centre (PMRC) of JAEA was established to address the challenge of laser-driven ion accelerator development for hadrons therapeutic. In the development of the instrument, it is necessary to do the bench-mark of the amount of the different types of radiation by the simulation code for shielding. The Monte Carlo Particle and Heavy Ion Transport code (PHITS) was used for bench-mark the dose on laser-shot radiations of short duration. The code predicts reasonably well the observed total dose as measured with a glass dosimeter in the laser-driven radiations.
SNU, Seoul
NCC, Korea, Kyonggi
Chung-Ang University, Seoul
Accelerator mass spectrometry (AMS) using a cyclotron has been studied because the system can be more compact and economical compared to the widespread commercial Tandem AMS. However, the previous efforts to build such a system showed that it has weakness in stability and transmission efficiency. To increase transmission efficiency it is important for the injection system to match not only the transverse phase space of a beam but also the longitudinal phase space with cyclotron acceptance. We plan to adopt a sawtooth RF buncher to increase transmission efficiency in the acceleration region of the cyclotron and a radial injection beam line. A goal in designing the injection line is to minimize the number of beam line elements to keep the system compact. The design of the injection system was carried out using the codes such as TRANSPORT and TRACE-3D. A prototype of the injection system is being constructed, and some results will be presented.
BNL, Upton, Long Island, New York
There is a dramatic increase in number of proton/carbon cancer therapy facilities in recent years due to their clear advantage over other radiation therapy treatments. The cost of ion cancer therapy is still prohibitive for most of the hospitals, and the dominant costs are beam delivery systems. We previously presented designs of carbon and proton isocentric gantries using non-scaling alternating gradient fixed field magnets (NS-FFAG) *, where gantry magnet size and weight are dramatically reduced. The weight of the transport elements of our NS-FFAG carbon isocentric gantry is 1.5 tons compared to 130 ton gantries recently constructed Heidelberg C facility at Heidelberg. We have also designed a proton NS-FFAG permanent magnet gantry with an estimated weight of 500 kg. We present an update on these designs.
* D. Trbojevic, B. Parker, E. Keil, and A. M. Sessler,
"Carbon/proton therapy: A novel gantry design," PHYSICAL REVIEW SPEC.
TOP. - ACCELERATORS AND BEAMS 10, 053503 (2007).
BNL, Upton, Long Island, New York
FRIB, East Lansing, Michigan
We present a medium-energy (4 GeV) electron ion collider (MeRHIC) lattice design for the Relativistic Heavy Ion Collider (RHIC). MeRHIC represents a staged approach towards the higher energy eRHIC, with MeRHIC hardware being reused for eRHIC. The lattice design includes two Energy Recovery Linacs (ERLs), multiple isochronous arcs connected to the ERLs, an interaction region design, a low energy ERL with a polarized electron source, and connecting beam lines.
* V. Litvinenko, proceedings from this conference.
Kyoto University, Photonics and Electronics Science and Engineering Center, Kyoto
A liquid cluster ion beam irradiation system has been developed for surface processing and modification of solid materials used in the semiconductor industry. The liquid clusters are produced by the adiabatic expansion method. The vapor pressure of the source materials such as water or ethanol is increased by heating, and ejected to a vacuum chamber through a supersonic nozzle. The ionized clusters by the electron impact ionization are accelerated to typically 3-9 kV after the elimination of monomers by the retarding voltage method, and irradiated on the solid surfaces. The sputtering yield of silicon by the ethanol cluster ion beam irradiation was more than 100 times larger than that by an argon monomer ion beam. On the other hand, the radiation damage and surface roughness caused by the ethanol cluster ion beam irradiation decreased when the mean cluster size was increased by increasing the retarding voltage. Irradiation effects of liquid cluster ion beams on polymers are also discussed.
Kyoto University, Photonics and Electronics Science and Engineering Center, Kyoto
In order to establish a shallow implantation of polyatomic carbons, a polyatomic ion source for organic liquids with a high-vapor pressure was developed. Vapor of n-octane was ionized by an electron bombardment, and the ion current of 230 μA was obtained at an extraction voltage of 2 kV. The mass spectra indicated that C3H7 ion was the highest in the ion concentration and some fragmentations of octane molecule took place, which might be caused by the electron bombardment. Depth profile of carbon into single crystalline silicon irradiated with C3H7 or C6H13 at different acceleration voltage was analyzed by X-ray photoelectron spectroscopy. As a result, the implanted depth increased with increase of the acceleration voltage. In addition, the C6H13 was implanted deeper than the C3H7 at the same incident energy per atom even though shallow implantation due to binary collision effect had been expected. The depth profile are also discussed in comparison with computer simulation results.
GSI, Darmstadt
IPCP, Chernogolovka, Moscow region
Universidad de Castilla-La Mancha, Ciudad Real
Rostock University, Rostock
Intense particle beams lead to volumetric heating of solid targets that generates large samples of High Energy Density (HED) matter. Such samples are very suitable to study the thermophysical properties of this important state of matter that spans over numerous fields of basic and applied physics. Facility for Antiprotons and Ion Research (FAIR) at Darmstadt, will generate very powerful bunched beams of the heaviest particles (uranium) that will deposit unprecedented high levels of specific power in the target. Extensive theoretical work has been carried out over the past decade to design HED physics experiments at the FAIR. So far, four different experimental schemes have been proposed. These include, HIHEX (Heavy Ion Heating and Expansion, which is suitable to study equation-of-state properties of HED matter), LAPLAS (Laboratory Planetary Science, which is suitable to generate physical conditions that exist in the interiors of the giant planets), Study of the growth of the Richtmyer-Meshkov instability and finally , the ion beam driven Ramp Compression which is suitable to study material properties like shear modulus and yield strength, under dynamic conditions.
JAEA/Kansai, Kyoto
Intense laser pulse is utilized to generate compact sources of electrons, ions, x-rays, neutrons. Recently, high energy negative ions are also observed in experiments using cluster or gas target*. To explain the acceleration of negative ions from laser-generated plasmas, we proposed Coulomb implosion mechanism**. When clusters or underdense plasmas are irradiated by an intense laser pulse, positive ions are accelerated inside the clusters or in the self-focusing channel by the Coulomb explosion. This could lead to the acceleration of negative ions towards target center. The maximum energy of negative ions is typically several times lower than that of positive ions. A theoretical description and corresponding Particle-in-Cell simulations of Coulomb implosion mechanism are presented. We show the evidence of the negative ion acceleration observed in our experiments using high intensity laser pulse and the cluster-gas targets.
* S.Ter-Avetisyan et al., J. Phys. B 37 (2004) 3633.
** T.Nakamura et al., Phys. Plasmas 16 (2009) 113106.
The University of Tokyo, Tokyo
RAPID (Rutherford Backscattering Spectroscopic Analyzer with Particle Induced X-ray Emission and Ion Implantation Devices), the University of Tokyo has been dedicated to various scientific and engineering studies in a wide range of fields by the ion beam analysis availability, including RBS, NRA, PIXE and ion implantation. The system consists of a 1.7MV tandem accelerator (Model 4117-HC,provided by HVEE corp., Netherland), two negative ion sources (a Cs sputter solid ion source and duoplasmatron gas ion source) and three beam lines. RAPID was installed in 1994 at Research Center for Nuclear Science and Technology, the University of Tokyo at first and since then it has been used for various research fields using ion beams. As the Center was reorganized to be a department of School of Engineering in 2005, the educational utilization came to be an important mission of RAPID. Besides several application studies with PIXE analysis, environmental analysis (pond sediments and atmospheric SPM (Suspended Particulate Matter) is performed as a student experiment. Recently, a low level ion irradiation system was also developed and applied for the study of CR-39 track detector with proton beam.
UTTAC, Tsukuba, Ibaraki
KEK, Ibaraki
University of Tokyo, Research Center for Nuclear Science and Technology, Tokyo
Accelerator Mass Spectrometry (AMS) is a highly sensitive mass spectrometric method for measuring rare isotopes. The technique is mainly applied in chronology, earth and environmental sciences to date samples using long-lived radioisotopes. With a multi-nuclide AMS system on the 12 MV Pelletron tandem accelerator at the University of Tsukuba (Tsukuba AMS system), we are able to measure environmental levels of long-lived radioisotopes of C-14, Al-26, Cl-36, Ca-41 and I-129 by employing a molecular pilot beam method. The high terminal voltage of 12 MV is an advantage for AMS to detect heavy radioisotopes. The principle of AMS and applications with the Tsukuba AMS system will be reported in this paper.
Department of Energy Sciences, Tokyo Institute of Technology, Yokohama
TIT, Yokohama
Kyushu University, Department of Applied Quantum Physics and Nuclear Engineering, Fukuoka
BNL, Upton, Long Island, New York
Warm Dense Matter (WDM) is an challenging problem because WDM, which is beyond ideal plasma, is low temperature and high density state with partially degenerate electrons and coupled ions. WDM is a common state of matter in astrophysical objects such as cores of giant planets and white dwarfs. The WDM studies require large energy deposition into a small target volume in a shorter time than the hydrodynamical time and need uniformity across the full thickness of the target. Since moderate energy ion beams (~ 0.3 MeV/amu) can be useful tool for WDM physics*, we propose WDM generation using Direct Plasma Injection Scheme (DPIS). In the DPIS, laser ion source is connected to the Radio Frequency Quadrupole (RFQ) linac directly without the beam transport line. The discussions of DPIS for WDM are presented.
* L. R. Grisham, Physics of Plasmas, 11, 5727 (2004).
GSI, Darmstadt
The FAIR SIS100 accelerator at GSI Darmstadt will be equipped with fast ramped superconducting magnets. The high current Uranium beam modes with intermediate charge states, require ultra low vacuum pressures that can be achieved in long term operation only by cold beam pipes acting as a cryopump with stable temperatures well below 12 K for all operating cycles. The straightforward layout for reliable cooling usually conflicts with an efficient design for fast ramped superconducting accelerator magnets, strongly affected by AC loss generation, field distortion and mechanical stability problems. A full functional vacuum chamber design for SIS 100 has to take into account all these conflicting boundary conditions and trade off between mechanical stability, acceptable field distortions, AC loss minimisation and achievable temperatures. We discuss the cooling conditions for the dipoles and for the beam pipe including first test results. The analysis of the principal design aspects for the vacuum chamber with respect to the magnets operation parameters and an integral design approach are given. We present a technological feasible solution for model testing and full scale manufacturing.
RCNP, Osaka
The RCNP accelerator cascade consists of an injector Azimuthally Varying Field (AVF) cyclotron (K=140) and a ring cyclotron (K=400). It provides ultra-high-quality beams and moderately high-intensity beams for a wide range of research in nuclear physics, fundamental physics, applications, and interdisciplinary fields. The maximum energy of protons and heavy ions are 400 and 100 MeV/u, respectively. Experimental apparatuses are used like a pair spectrometer, a neutron time of flight facility with a 100 m long tunnel, a radioactive nuclei separator, a super-thermal ultra cold neutron (UCN) source, a white neutron source, and a RI production system for nuclear chemistry. Such ultra high resolution measurements as dE/E = 5x10-5 are routinely performed with the Grand-Raiden spectrometer by utilizing the dispersion matching technique. The UCN density was observed to be 15 UCN/cm3 at the experimental port at a beam power of 400 W. Some topics on the research are discussed in the talk.
JINR, Dubna, Moscow Region
NICA (Nuclotron-based Ion Collider fAcility) is the new accelerator complex currently under construction at JINR. The facility is aimed to provide collider experiments with heavy ions up to uranium (gold at the beginning stage) with a centre of mass energy up to 11 GeV/u and an average luminosity up to 1027 cm-2 s-1. The collisions of polarized deuterons and protons are foreseen also. The accelerator complex includes two injector linacs, a superconducting booster synchrotron, a 6 GeV/u superconducting synchrotron (existing Nuclotron) and a collider consisting of two storage rings. Different modifications of superferric magnets based on a hollow composite NbTi cable operating at 4.5 K is proposed to be used for the NICA booster and collider rings. The twin-aperture collider dipole consists of two vertically assembled cold masses placed inside a common thermal shield and a common cryostat. The dipole good field aperture is fixed to 60 mm. The 2 T option, which design is very similar to the Nuclotron's one, was fixed as basis for the collider of 350 m long. R&D work on a curved 4 T Cosine(θ)-dipoles based on a hollow Nuclotron-type cable is proposed to be continued.
CERN, Geneva
The layout of the interaction region for the LHC upgrade project is based on a number of new magnets that will provide the required strengths to focus the colliding beams as well as to separate them after the collision. As in the nominal LHC, a triplet of quadrupole magnets is foreseen for the upgrade optics and in addition a separator dipole to limit the parasitic bunch crossings of the two counter rotating bunch trains. Due to the smaller beta function at the IP however, the requirements for the free aperture of these IR magnets are more demanding and the effect of the higher order multipoles is more severe than under the nominal LHC conditions. Using the tracking simulations to study these effects, target values for the multipole coefficients of the new magnets have been defined as well as a multipole correction scheme that will be used to compensate those field errors which cannot be avoided due to design and construction tolerances. Based on these considerations the required field quality of the new LHC low beta magnets is discussed and the resulting dynamic aperture for different multipole correction scheme is presented.
CERN, Geneva
Following the LHC injection tests of 2008, two injection tests took place in October and November 2009 as preparation for the LHC restart on November 20, 2009. During these injection tests beam was injected through the TI2 transfer line into sector 23 of ring 1 and through TI8 into the sectors 78, 67 and 56 of ring 2. The beam time was dedicated to injection steering, optics measurements and debugging of all the systems involved. Because many potential problems were sorted out in advance, these tests contributed to the rapid progress after the restart. This paper describes the experiences and issues encountered during these tests as well as related measurement results.
BNL, Upton, Long Island, New York
During the acceleration process, heavy ion beams in RHIC cross the transition energy. When RHIC was colliding deuterons and gold ions during Run-8, lattices with different integer tunes were used for the two rings. This resulted in the two rings crossing transition at different times, which proved beneficial for the "Yellow" ring, the RF system of which is slaved to the "Blue" ring. For the symmetric gold-gold run in FY2010, lattices with different transition energies but equal tunes were implemented. We report the optics design concept as well as operational experience with this configuration.
RCNP, Osaka
An upgrade program of the RCNP cyclotron facility for increase of beam intensity and improvement of beam quality is in progress to meet requirements from research in nuclear physics and industrial applications using secondarily produced particles such as neutrons, muons and radioisotopes. A 2.45 GHz ECR ion source using a set of permanent magnets was developed for high intensity proton beam production. The proton beam intensity more than 0.5 mA at an extraction energy of 15 keV has been obtained with a proton ratio more than 80 %. The quality of the pre-accelerated beam from the K140 injector AVF cyclotron has been improved by a flat-top(FT) acceleration system to enhance the beam transmission to the K400 ring cyclotron. Transversal resonant mode of a dee electrode with a span angle of 180 degrees was investigated to achieve the FT acceleration in the frequency region from 50 to 60 MHz. In this paper, developments for high intensity proton beam acceleration and beam quality improvement using the FT acceleration system of the AVF cyclotron will be mainly presented.
JINR, Dubna, Moscow Region
In order to decrease the energy of an ion accelerated in a cyclotron on value of some MeV/eau it is possible to run an ion beam through a thin metal foil (degrader). One can calculate the final ion energy, angular and energy stragglings, which the beam attains in the degrader, for example, by means of code LISE++. The formulae for calculation of the beam second order moments after degrader were obtained. The formulae for calculation of final beam momentum spread, new values of rms beam emittances, Twiss parameters and the dispersion functions were also obtained. The new ion beam parameters allow one to calculate the beam transportation along the beam line after degrader.
EPFL, Lausanne
TERA, Novara
Hadrontherapy, the technique of tumor radiotherapy employing heavy ion beams, is developing rapidly(*). The TERA Foundation proposes an innovative dedicated accelerator, called Cyclinac(**). It is composed of a 230 MeV/u cyclotron providing fast pulsed beams of H2+, for proton therapy with standard techniques, or C6+, injected into a high gradient linac. Its energy can thus be modulated from pulse to pulse (up to 400 MeV/u), for optimal irradiation of solid tumors with the most modern techniques of dose active spreading. A preliminary design of a superconducting synchrocyclotron for this application is presented. Its advantages are the reduced construction and operating costs (small magnet and low RF power consumption), and the good adaptation of its beam characteristics to therapy (low current and fast repetition rate). The magnet features a central field of 5 T, which has azimuthal symmetry and decreases with the radius, ensuring radial and vertical focusing. The weight is around 300 t. Ions are produced in an EBIS, injected axially and resonantly extracted at 1 m radius. The RF is mechanically modulated by a rotating capacitor, providing the required 400 Hz repetition rate.
* U. Amaldi, G. Kraft, J.Rad. Res., 48 Suppl A (2007) 27
** U. Amaldi, S. Braccini, P. Puggioni, Reviews of Accelerator Science and Technology, Vol.2 (2009)
KEK, Ibaraki
Nagaoka University of Technology, Nagaoka, Niigata
New acceleration system using an induction cell has been developed at KEK by using KEK 12-GeV PS*. We call an accelerator using the induction acceleration system "Digital Accelerator". The PS-Booster is now being renovated as the first Digital Accelerator (DA) by introducing the induction acceleration instead of rf**. Argon ion beam from the ECR ion source is injected to the DA by an electrostatic beam kicker. Another electrostatic device with the same structure is used for chopping the beam before injection. The accelerated beam is extracted by the existing extraction system, which comprises bump, septum and kicker magnets. Since these magnets are installed in a vacuum chamber, vacuum pressure deteriorates due to outgas from them. In order to reduce a beam loss in the DA ring, the pressure level is crucial especially for an ion beam. Therefore, we decided to put the septum magnet outside the vacuum chamber and insert a vacuum duct in the gap, since it dominantly contributes to the vacuum pressure more than the other magnets. This paper describes the electrostatic beam chopper, injection kicker and septum magnet containing the vacuum duct for the KEK DA and beam dynamics.
*K. Takayama, Phys. Rev. Lett. 98, 054801 (2007)
**K. Takayama, "KEK Digital Accelerator for Material and Biological Sciences", T. Iwashita, "Induction Acceleration System", in this conference
KEK, Ibaraki
SAMEER, Mumbai
Tokyo City University, Tokyo
The KEK-DA (Digital Accelerator) is a modification of the KEK 500 MeV booster*, in which an induction acceleration system is employed. It has an ability to accelerate arbitrary ions with their possible charge states**. An outline of the acceleration scenario is described and a necessary control system fully integrating the induction acceleration system is given in details. The KEK-DA is a rapid cycle synchrotron operating at 10 Hz; the accelerating pulse voltage must be dynamically varied in time to follow the ramping magnetic field. A novel technique combining the pulse density control and intermittent operation of acceleration cells is required. The intelligent gate control system which uses 1 GHz digital signal processors (DSPs) has been designed. Construction of the KEK-DA is in the final stage; installation of the induction cells and the power supplies are done. The whole system including gate control system is demonstrated with high voltage outputs,long-term stability of the system through a heat run is examined. Also a future plan which replaces DSPs by FPGA (Field Programmable Gate Array)is discussed.
* K.Takayama et al., JOURNAL OF APPLIED PHYSICS 101, 063304 (2007).
** K.Takayama et al., "KEK Digital Accelerator for Material and Biological Sciences" in this conference.
KEK, Ibaraki
Nagaoka University of Technology, Nagaoka, Niigata
Sokendai, Ibaraki
Tokyo City University, Tokyo
RBRC, Upton, Long Island, New York
Nippon Advanced Technology Co. Ltd., Ibaraki-prefecture
Iwate university, Morioka, Iwate
A novel circular accelerator capable of accelerating any ions from an extremely low energy to relativistic energy is discussed. A digital accelerator (DA)* is based on the induction synchrotron concept, which had been demonstrated in 2006. All ions are captured and accelerated with pulse voltages generated by induction acceleration cell (IAC). The IAC is energized by the switching power supply, in which power solid-state conductors are employed as switching elements and their tuning on/off is maneuvered by gate signals digitally manipulated from the circulating signal of an ion beam. Acceleration synchronized with the revolution of the ion beam is always guaranteed. The concept is realized by renovating the KEK 500 MeV booster into the DA, introducing a laser ablation ion source. Ion energy of 85-140 MeV/au and intensity of 10+9 - 10+10 /sec are estimated and these ions will be delivered without any large-scale injector. Companion papers** will discuss more details of instruments of DA. Applications for innovative material sciences and life sciences will be briefly introduced as well as the outline of DA.
*K. Takayam, J. of Appl. Phys. 101 (2007) 063304.
**K.Takayama "Ion source and LEBT", T.Adachi "Injection and extraction system", T.Iwashita "Induction acceleration system" in this conference.
KEK, Ibaraki
Nagaoka University of Technology, Nagaoka, Niigata
Sokendai, Ibaraki
Nippon Advanced Technology Co. Ltd., Ibaraki-prefecture
KEK digital accelerator (DA) capable of accelerating all species of ion* is an induction synchrotron employing no large scale injectors. At the beginning of its operation, Ar ions from the ECR ion source (ECRIS) embedded in the 200 kV high voltage terminal (HVT) are directly injected into KEK-DA though the low energy BT line (LEBT). The permanent magnet ECRIS was assembled at KEK. Its characteristics such as a charge-state spectrum, emittance, and intensity are presented. The 200 kV HVT has been also assembled at KEK. Its voltage stability in the pulse mode operation, where a plasma of 1 msec is created by x-band microwaves at 10 Hz, is discussed. The LEBT consists of the Eintzel lens, momentum analyzer, B magnets with edge focusing, electrostatic chopper**, and a combination of Q magnets. In the upper LEBT from the ion extraction hall to the entrance of the analyzer, possible charge-state ions are contaminated in the space-charge limit and beam focusing is realized through the Eintzel lens and tandem acceleration gaps. In the lower LEBT from the analyzer to the KEK-DA injection point, the lattice has been optimized so as to meet optics matching at the injection point.
*K. Takayama, J. of Appl. Phys. 101 063304(2007), "KEK digital accelerator for material and biological sciences" in this conference
**T.Adachi, "Injection and extraction system" in this conference
IAP, Frankfurt am Main
TU Darmstadt, Darmstadt
GSI, Darmstadt
StrahlSim is a unique code for the simulation of charge exchange driven beam loss and dynamic vacuum effects in heavy ion synchrotrons. Dynamic vacuum effects are one of the most challenging problems for accelerators using intermediate charge state, high intensity heavy ion beams (e.g. AGS Booster, LEIR, SIS18). StrahlSim can be used as a design tool for synchrotrons, e.g. for the estimation of pumping power needed to stabilize the dynamic vacuum. Recently, StrahlSim has been extended to simulate time dependent longitudinal pressure profiles. The new code calculates a self-consistent static pressure distribution along the accelerator and simulates local pressure rises caused by dynamic and systematic beam losses. StrahlSim determines the loss distribution of charge exchanged beam ions and respects the beam energy dependence of the charge exchange cross sections. The beam loss calculated by means of the new time dependent longitudinal pressure profiles has been benchmarked with measured data from the latest SIS18 machine experiments.
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken
KEK, Ibaraki
The J-PARC RFQ (length 3.1m, 4-vane type, 324 MHz) accelerates a beam from the ion source to the DTL. The beam test of the linac was started in November 2006 and 181 MeV beam was successfully accelerated in January 2007. Since then, the linac has been delivered beams for commissioning of the linac itself, downstream accelerators and facilities. Trip rates of the RFQ, however, unexpectedly increased in Autumn 2008, and we have been suffering from this issue for user run operation since then. We tried to recover by tender conditioning, modification of RF control, improvement of vacuum properties and so on. By taking these measures, we manage to have 2 to 3 days continuous beam operation. In this report, we describe the status of the RFQ.
STFC/RAL/ISIS, Chilton, Didcot, Oxon
Imperial College of Science and Technology, Department of Physics, London
Fundación TEKNIKER, Eibar (Gipuzkoa)
University of Warwick, Coventry
Bilbao, Faculty of Science and Technology, Bilbao
ESS-Bilbao, Zamudio
University of the Basque Country, Faculty of Science and Technology, Bilbao
STFC/RAL/ASTeC, Chilton, Didcot, Oxon
ESS Bilbao, Bilbao
Fermilab, Batavia
STFC/RAL, Chilton, Didcot, Oxon
The Front End Test Stand (FETS) under construction at the Rutherford Appleton Laboratory is the UK's contribution to research into the next generation of High Power Proton Accelerators (HPPAs). HPPAs are an essential part of any future Spallation Neutron Source, Neutrino Factory, Muon Collider, Accelerator Driven Sub-critical System, Waste Transmuter etc. FETS will demonstrate a high quality, high intensity, chopped H-minus beam and is a collaboration between RAL, Imperial College and the Universtity of Warwick in the UK and the Universidad del Pais Vasco in Spain. This paper describes the current status and future plans of FETS.
University of Warwick, Coventry
Fundación Tekniker, Elbr (Guipuzkoa)
Bilbao, Faculty of Science and Technology, Bilbao
Fundación TEKNIKER, Eibar (Gipuzkoa)
STFC/RAL, Chilton, Didcot, Oxon
STFC/RAL/ASTeC, Chilton, Didcot, Oxon
STFC/RAL/ISIS, Chilton, Didcot, Oxon
Elytt Energy, Madrid
Imperial College of Science and Technology, Department of Physics, London
The Front End Test Stand (FETS) at the Rutherford Appleton Laboratory is intended to demonstrate the early stages of acceleration (0-3 MeV) and beam chopping required for high power proton accelerators, including proton drivers for pulsed neutron spallation sources and neutrino factories. A Low Energy Beam Transport (LEBT), consisting of three solenoids and four drift sections, is used to transport the H- beam from the ion source to the FETS Radio Frequency Quadrupole. We present the status of the installation and commissioning of the LEBT, and compare particle dynamics simulations with preliminary measurements of the H- beam transport through the LEBT.
ORNL, Oak Ridge, Tennessee
The Spallation Neutron Source accelerator complex consists of a 2.5 MeV H- front-end injector system, a 186 MeV normal-conducting linear accelerator, a 1 GeV superconducting linear accelerator, an accumulator ring, and associated beam transport lines. Since initial operation began in 2006, the beam power has been steadily increasing toward the design goal of 1.4 MW. In September 2009 the power surpassed 1 MW for the first time, and operation at the 1 MW level is now routine. The status of the beam power ramp-up program and present operational limitations will be described.
Kyoto ICR, Uji, Kyoto
We aim to develop a small and high intensity proton source for a compact accelerator based neutron source. Because this proton source shall be located close to RFQ for simplification, ratio of H+ to molecular ions such as H2+ or H3+ must be large. Therefore, we selected an ECR ion source with permanent magnets as small and high intensity ion source. ECR ion sources can provide high H+ ratio because of their high plasma temperature. Using permanent magnets makes the ion source small and running cost low. Because there is no hot cathode, longer MTBF is expected. Usually, gas is fed into ion sources continuously, even if ion sources run in pulse operation mode. But, continuous gas flow doesn't make vacuum in good level. So, we decided to install pulse gas valve directly to the plasma chamber. Feeding the gas only when the ion source is in operation reduces the gas load to the evacuation system and the vacuum level can be kept high. Up to now, we developed the first and second model of the ion source. And the research is being conducted using the second model. Recent experimental results will be presented.
GSI, Darmstadt
FIAS, Frankfurt am Main
After partially completing the upgrade program of SIS18, the number of intermediate charge state heavy ions accelerated to the FAIR booster energy of 200 MeV/u, could be increased by a factor of 50. Meanwhile, more than 1010 Uranium ions with charge state 27+ have been accelerated with moderate beam loss by ionization and reasonably stable residual gas pressure conditions. The specific challenge for the SIS18 booster operation is the high cross section for ionization due to the low charge state in combination with gas desorption processes and the dynamic vacuum pressure. Especially for this operation mode which is requied to match the intensity requirements for FAIR, an extended upgrade program of SIS18 is presently ongoing and partially completed. The achieved progress in minimizing the ionization beam loss underlines that the chosen technical strategies described in this report are appropriate.
JINR, Dubna, Moscow Region
JINR/LHE, Moscow
The main goal of the Nuclotron booster construction are following: accumulation up to 4·10+9 Au32+ ions; acceleration of the ions up to energy of 600 MeV/u that is sufficient for stripping of the ions to the bare nucleus state; simplification of the requirements to the vacuum conditions in the Nuclotron; forming of the required beam emittance at the energy of 100 MeV/u with electron cooling system. The features of this booster, the requirement to the main synchrotron systems and their parameters are presented.
JINR, Dubna, Moscow Region
BINP SB RAS, Protvino, Moscow Region
JINR/LHE, Moscow
The 'Nuclotron-M' project started in 2007 is considered as the key point of the first stage of the NICA/MPD project. General goal of the 'Nuclotron-M' project is to prepare all the systems of the Nuclotron for its long and reliable operation as a part of the NICA collider injection chain. Additionally the project realization will increase the Nuclotron ability for realization of its current experimental program. Results of the last runs of the Nuclotron operation are presented.
JINR, Dubna, Moscow Region
RAS/INR, Moscow
IHEP Protvino, Protvino, Moscow Region
MEPhI, Moscow
The injector complex of the NICA facility consists of existing Alvarez-type linac LU-20 and new heavy ion linac HILac. The LU-20 is under modernization now, the HILac will be constructed during coming years. Parameters of the accelerators are presented.
JINR, Dubna, Moscow Region
JINR/LHE, Moscow
The Nuclotron-based Ion Collider fAcility (NICA) is the new accelerator complex being constructed at JINR aimed to provide collider experiments with heavy ions up to uranium at the center of mass energy from 4 to 11 GeV/u. It includes 6 Mev/u linac, 600 MeV/u booster, upgraded SC synchrotron Nuclotron and collider consisting of two SC rings, which provide average luminosity of the level of 1027cm-2s-1.
WERC, Tsuruga , Fukui
We have operated the accelerator system which consists of a tandem accelerator and a synchrotron since the completion of the construction and beam commissioning at the Wakasa-wan Energy Research Center, Tsuruga, Japan in 2000. The acceleration voltage of the tandem accelerator amounts to 5 MV and is generated by the Dynamitron-type cascade voltage doubler rectifier. The beam from the tandem accelerator is transported to the MeV-ion experimental area for the irradiation to the industrial or biological material and for the ion beam analysis. The tandem beam is also injected to the 200 MeV proton synchrotron. The synchrotron beam has been used for the high energy irradiation and the cancer therapy. The tandem accelerator is used for a lot of purposes including cancer therapy, therefore, stable operation of the system and efficient sharing of the operation duration are required. Developments of the accelerator are presented putting a stress on the stable and efficient operation of the system in this paper.
BINP SB RAS, Novosibirsk
An electrostatic tandem accelerator with 1.25 MV at the high voltage terminal was designed, assembled and successfully commissioned at BINP. The accelerator of ELV-type will be used as injector for cancer therapy facility by carbon ions beams. The 10 keV beam of negative carbon ions with current up to 100 mkA is injected into the tandem and charge exchange in the vacuum heat insulation magnesium vapor target. The results of commissioning tests and beam parameters measurements are presented.
KACST, Riyadh
JINR, Dubna, Moscow Region
Cockcroft Institute, Warrington, Cheshire
At the National Centre for Mathematics and Physics (NCMP), at the King Abdulaziz City for Science and Technology (KACST), Saudi Arabia, a versatile low energy ion injector has been developed in collaboration with the QUASAR group. This project will allow for a broad experimental program with most different kinds of ions both in single pass setups, but also with ions stored in a fixed-energy electrostatic storage ring. In this contribution, the design of the injector is presented. It was designed for beams with energies of up to 30 kV/q and will allow for switching between different ion sources from e.g. duoplasmatron to electrospray ion sources and to thus provide the users with a wide range of different beams. The mechanical construction of the injector is summarized and the status of its assembly at KACST presented.
JINR, Dubna, Moscow Region
Cockcroft Institute, Warrington, Cheshire
The Ultra-Low energy Storage Ring (USR) within the future Facility for Low-energy Antiproton and Ion Research (FLAIR) will decelerate antiproton beams from 300 keV to energies of only 20 keV. Cooled beams will then be extracted and provided to external experiments. The large variety of planned experiments requires a highly flexible longitudinal time structure of the extracted bunches, ranging from ultra-short pulses in the nanosecond regime to quasi DC beams. This requires fast as well as slow extraction in order to cover whole range of envisaged beam parameters. A particular challenge was to combine elements for fast and slow extraction in one straight section of this electrostatic ring. In this contribution we present the results of beam dynamic simulations and describe the overall extraction scheme in detail.
Cockcroft Institute, Warrington, Cheshire
The University of Liverpool, Liverpool
The Marie Curie Initial Training Network DITANET covers the development of advanced beam diagnostic methods for a wide range of existing or future accelerators, both for electrons and ions. The network brings together research centres like CERN or DESY, Universities, and private companies. DITANET currently has 27 partners from Europe and the USA and is committed to training young researchers in this field, performing cutting edge research in beam instrumentation, and exploiting synergies within this community. This contribution presents an overview of the research outcomes within the first two years of DITANET and summarizes the network's training activities.
on behalf of the DITANET Consortium.
Cockcroft Institute, Warrington, Cheshire
INFN/LNS, Catania
The University of Liverpool, Liverpool
Future atomic and nuclear physics experiments put challenging demands on the required beam instrumentation. Low energy (<1 MeV), low intensity (<107 pps) beams will require highly sensitive monitors. This is especially true for the Facility for Low-energy Antiproton and Ion Research (FLAIR) where antiproton beams will be decelerated down to 20 keV and as few as 5·105 particles per second will be slowly extracted for external experiments. In order to investigate the limits of scintillating screens for beam profile monitoring in the low energy, low intensity regime a structured analysis of several screen materials, including CsI:Tl, YAG:Ce and scintillating fibre optic plate (SFOP), has been done under different irradiation conditions with keV proton beams. This contribution will present the experimental setup and summarize the results of this study.
GSI, Darmstadt
IAP, Frankfurt am Main
The super heavy element research is one of the outstanding projects at GSI. At SHIP* six new elements have been discovered; moreover, nuclear chemical experiments with transactinides were recently performed at TASCA**. This experimental program strongly benefits from high average beam intensities. In the past beam currents were raised significantly by a number of improvements. The present upgrade program comprises the installation of a superconducting (sc) 28 GHz ECR ion source, a new frontend (low energy beam transport and RFQ), and, in the long term, an sc cw Linac. For the short term, the new RFQ will raise the duty factor by a factor of two (50%), limited by the following accelerator only. This bottleneck will be resolved by the applied cw Linac. Beam tests with a newly developed sc CH cavity are scheduled for 2012. The setup of the RFQ as the major upgrade of the 20 year old HLI*** is in progress, the commissioning will be finished in March 2010. Besides a higher duty factor, improved longitudinal beam quality and transmission are expected. This paper reports on the challenging rf and beam commissioning.
* Separator for Heavy Ion Reaction Products
** TransActinide Separator and Chemistry Apparatus
*** High charge state injector, a part the UNILAC
GSI, Darmstadt
This paper describes the development of a new rf accelerating cavity based on novel magnetic alloy materials (MA-materials) for operation at harmonic number h=2 (f=0,43- to 2,8 MHz) to provide the necessary accelerating voltage for SIS18 injector operation with high intensity heavy ion beams in a fast operation mode with three cycles per second. The acceleration system consist of three units which are able to operate independently from each other. That is important, since each ion for FAIR has to cross the h=2-rf-system and in the case of a damage a reduced operation has to be ensured. Since the cavities are filled with lossy MA-ring-cores, which are iron based Finemet FT3M ring cores from Hitachi, the cavities show a broadband behaviour and thus no cavity tuning during the acceleration ramp will be necessary. Due to the high saturation field strength of Finemet (1,2 T) the overall length of all three cavity units can be very short. This is an important feature since due to many insertions which were additionally inserted into the synchrotron ring SIS12/18 in the meantime, the available length in SIS12/18 for the cavity units is with 4 m very short.
IAP, Frankfurt am Main
GSI, Darmstadt
At the Institute for Applied Physics a superconducting CH-Cavity (Crossbar H-Mode) has been developed. It is the first multi-cell drift tube cavity for the low and medium energy range of proton and ion linacs. A 19 cell, β = 0.1 prototype cavity has been fabricated and tested successfully with a voltage of 5.6 MV corresponding to gradients of 7 MV/m. The construction of a new superconducting 325 MHz 7-gap CH-cavity has started. This cavity has an optimized geometry with respect to tuning possibilities, high power RF coupling, minimized end cell lengths and options for surface preparation. Static tuning is carried out by small niobium cylinders on the girders. Dynamic tuning is performed by a slow bellow tuner driven by a step motor and a fast bellow tuner driven by a piezo. Additional thermal and mechanical simulations have been performed. It is planned to test the cavity with a 10 mA, 11.4 AMeV (β = 0.158) beam delivered by the Unilac at GSI. Another cavity (f = 217 MHz, β = 0.059) is currently under development for the cw Heavy Ion Linac at GSI. It is the first of nine sc CH-Cavities planned for this project covering an energy range from 1.4 to 7.3 AMeV.
IAP, Frankfurt am Main
The goal of the Frankfurt Funneling Experiment is to multiply beam currents by merging two low energy ion beams. In an ideal case this would be done without any emittance growth. Our setup consists of two ion sources, a Two-Beam-RFQ accelerator and a multi cell deflector which bends the beams to one common beam axis. The end section of the RFQ electrodes are designed to achieve a 3d focus at the crossing point of the two beam axis. New simulations with the RFQSIM-Code for a matching system with extended electrodes will be presented.
IAP, Frankfurt am Main
Funneling is a method to increase low energy beam currents in multiple stages. The Frankfurt Funneling Experiment is a model of such a stage. The experiment is built up of two ion sources with electrostatic lens systems, a Two-Beam-RFQ accelerator, a funneling deflector and a beam diagnostic system. The two beams are bunched and accelerated in a Two-Beam RFQ. A funneling deflector combines the bunches to a common beam axis. Current work is beam tests with the new beam matching section. First funneling beam and energy measurements with the improved Two-Beam-RFQ will be presented.
Consorzio RFX, Associazione Euratom-ENEA sulla Fusione, Padova
INFN/LNL, Legnaro (PD)
GREPHE/LAPLACE, Toulouse
The thermonuclear fusion experiment ITER, requires 33 MW of auxiliary heating power from two Neutral Beam Injectors (NBI), each of them providing 40 A of negative deuterium ions. The EU activities oriented to the realisation of the electrostatic accelerator comprise the construction in Padova of SPIDER, a facility devoted to the optimisation of the beam source. SPIDER parameters are: 100 keV acceleration, 40/60 A (deuterium/hydrogen) current. For the optimised SPIDER accelerator the present contribution provides a characterisation of secondary particles, which include electrons produced by impact of ions on grid surfaces, stripped from negative ions inside the accelerator, and produced by ionisation of the background gas, and the corresponding positive ions. Currents and heat deposited on the various grids and spatial distribution by secondaries will be described. It is found that most of the heat loads on the accelerator grids is due to electrons; moreover the features of secondaries exiting the accelerator and back-streaming towards the source will be presented. The results will be compared with old investigations concerning the NBI 1 MeV accelerator.
RLNR, Tokyo
A new type Linac, HSC (hybrid single cavity) linac for cancer therapy, which configuration combines RFQ (Radio Frequency Quadrupole) accelerating structure and DT (Drift Tube) accelerating structure is being finished designs and simulations now. This HSC linac design had adopted advanced power-efficiency-conformation, IH (Interdigital H) structure, which acceleration efficiency is extremely high in the low-middle energy region, and had also adopted most advanced computer simulation technology to evaluate cavity electromagnetic distribution. The study purposes of this HSC linac focus to design of injector linac for synchrotron of cancer radiotherapy facilities. Here, this HSC linac has an amazing space effect because of compact size by coupled complex acceleration electrode and integrated the peripheral device which is made operation easy to handle.
ITEP, Moscow
The new heavy ion high current injector for ITEP-TWAC Facility is now under construction at ITEP for acceleration of ions with 1/3 charge to mass ratio up to energy of 7 MeV/u and beam current of 100 mA. The 81.5 MHz RFQ section based on 4 vane resonator with magnetic coupling windows is constructed for the beam energy of 1.566 MeV/u. The RF tuning of RFQ section has been presently completed and basically confirms the expected parameters calculated by 3D OPERA codes. The windows improve both azimuthal and longitudinal stabilization of the operating mode by increasing the separation from parasitic modes. The second section of 163 MHz H-type resonator is designed and in progress for construction. Status of machine construction activity and beam dynamics calculation are presented.
Imperial College of Science and Technology, Department of Physics, London
STFC/RAL/ISIS, Chilton, Didcot, Oxon
STFC/RAL, Chilton, Didcot, Oxon
This paper will present the mechanical engineering design for a 324 MHz 4-vane RFQ, which has been developed for the Front End Test Stand (FETS) project based at the Rutherford Appleton Laboratory (RAL) in the UK. The design criteria will be discussed along with particular design features of the RFQ including the tuners, vacuum ports, main body cooling pocket design and the support / alignment structure. Different techniques for creating the RF and vacuum seal between major and minor vanes are also discussed.
STFC/RAL/ISIS, Chilton, Didcot, Oxon
STFC/RAL/ASTeC, Chilton, Didcot, Oxon
Imperial College of Science and Technology, Department of Physics, London
The front end test stand (FETS) [1] is entering the next stage of construction and commissioning, with the three-solenoid magnetic low energy beam transport (LEBT) line being installed. A thorough characterization of the beam leaving the Penning H- ion source has been performed. This includes measurements of the beam current using toroids and of the transverse emittance using slit-slit scanners. These measurements are performed over a wide range of source discharge and extraction parameters in order to understand how the transmission may be improved. Comments on the quality of the beam to be injected into the FETS radio frequency quadrupole (RFQ) are given.
Imperial College of Science and Technology, Department of Physics, London
JAI, Egham, Surrey
The PAMELA (Particle Accelerator for MEdicaL Applications) project aims to design an ns-FFAG accelerator for cancer therapy using protons and carbon ions. For the injection system for carbon ions, an RFQ is one option for the first stage of acceleration. Our integrated RFQ design process* has been developed further using Comsol Multiphysics for electric field modelling. The design parameters for the RFQ are automatically converted to a CAD model using Autodesk Inventor, and the electric field map for this model is simulated in Comsol. Particles can then be tracked through this field map using Pulsar Physics' General Particle Tracer (GPT). Our software uses Visual Basic for Applications and MATLAB to automate this process and allow for optimisation of the RFQ design parameters based on particle dynamical considerations. Possible designs for the PAMELA RFQ, including super-conducting and normal-conducting solutions, will be presented and discussed, together with results of the field map simulations and particle tracking for these designs.
* M J Easton et al., RFQ Design Optimisation for PAMELA Injector, PAC09, Vancouver, Canada, April 2009, FR5REP066.
LANL, Los Alamos, New Mexico
We are developing high-efficiency normal-conducting RF accelerating structures based on inter-digital H-mode (IH) cavities and the transverse beam focusing with permanent-magnet quadrupoles (PMQ), for beam velocities in the range of a few percent of the speed of light. Such IH-PMQ accelerating structures following a short RFQ can be used in the front end of ion linacs or in stand-alone applications, e.g. a compact deuteron-beam accelerator up to the energy of several MeV. Results of combined 3-D modeling for a full IH-PMQ accelerator tank ' electromagnetic computations, beam-dynamics simulations with high currents, and thermal-stress analysis ' are presented. The accelerating field profile in the tank is tuned to provide the best beam propagation using coupled iterations of electromagnetic and beam-dynamics modeling. A cold model of the IH-PMQ tank is being manufactured.
GSI, Darmstadt
Nagaoka University of Technology, Nagaoka, Niigata
FZJ, Jülich
JINR, Dubna, Moscow Region
The stochastic cooling is employed to reduce the momentum spread of accelerated 2 GeV proton beam at COSY. In addition the barrier voltages are successfully used to compensate the mean energy loss of the beam due to the thick internal target such as pellet target. To analyze the experimental results at COSY, we have developed the particle tracking code which simulate the particle behavior under the influences of stochastic cooling force, Schottky diffusion, thermal diffusion and IBS effects. The synchrotron motion due to the RF fields are included with 4th order symplectic way. The simulation results are well in agreement with the observed cooling process for the case of barrier voltage as well as RF field of harmonic number=1. In the present paper, the systematic analysis of the experimental results with use of the developed tracking codes are described. In addition the process of short bunch formation at the heavy ion collider at NICA project is investigated with use of the stochastic cooling. In that case the strong IBS effects are main limiting factor of making and keeping the short bunch as well as the space charge effects. Details of the simulation study will be presented.
GSI, Darmstadt
Nagaoka University of Technology, Nagaoka, Niigata
FZJ, Jülich
JINR, Dubna, Moscow Region
Anti-proton beam accumulation at CERN and FNAL has been performed with use of stochastic stacking in the momentum space. Thus accumulated beam has a large momentum spread and resultantly large radial beam size with large dispersion ring. In the present proposed scenario, beams from the pre-cooling ring are injected into the longitudinal empty space prepared by the barrier voltages and subsequently the stochastic cooling is applied. After the well cooling, barrier voltages will prepare again the empty space for the next beam injection. We have simulated the stacking process up to 100 stacking with use of the bunched beam tracking code including the stochastic cooling force and the diffusion force such as Schottky diffusion term, thermal diffusion, IBS effects. The synchrotron motion by barrier voltages are included with 4th order symplectic method. Examples of the application to 3 GeV anti-proton beam for the HESR ring in FAIR project are presented as well as the accumulation of heavy ion beam 3.5 GeV/u Au, at the NICA collider at JINR project.
GSI, Darmstadt
The ESR storage ring at GSI is operated with a wide range of heavy ions. In addition to stable heavy ions also rare isotope beams are studied in various experiments. A novel method to provide one- or few-component cooled fragment beams has been demonstrated experimentally. This technique uses a primary high energy heavy ion beam (several hundred MeV/u) bombarding a thick target in front of the storage ring. The reaction products are first separated by the magnetic structure of the storage ring. After storage of isotopes in a rigidity window of typically ± 2 per mille the isotopes are cooled to the same velocity by electron cooling. The cooled ions are circulating on different orbits according to their mass and charge. The momentum spread of the individual components is on the order 0.01 per mille or smaller depending on the intensity. The different components are radially well separated in regions with large dispersion. By the use of mechanical scrapers beam components in a certain radial region, corresponding to a range in masses and charges, can be selected, This way the stored rare isotope beam is curtailed to the components of choice.
National Technical University of Athens, Zografou
A compact ring with an internal target for the production of Li-8 or B-8 as neutrino or antineutrino emitters has been proposed*, to enhance the flux of radioactive isotopes for a beta-beam facility. The circulating beam is expected to survive for thousands of turns and, according to this scheme, the ionization cooling provided by the target itself and a suitable RF system will be enough to keep the beam transverse and longitudinal emittances under control. The ionization cooling potential for a preliminary ring design is here investigated by means of tracking simulations and analytical considerations, keeping in mind that a correct modeling of the beam-target interactions is fundamental for these studies. Technological issues for such a ring and possible show-stoppers are also briefly discussed.
* C.Rubbia et al, NIM-A 2006..
Kyoto ICR, Uji, Kyoto
Kyoto IAE, Kyoto
NIRS, Chiba-shi
In order to achieve three dimensional crystal beam, laser cooling forces are required not only in the longitudinal direction, but also in the transverse directions. With the resonance coupling method*, transverse temperature is transmitted into longitudinal direction, and we have already demonstrated horizontal laser cooling experimentally **. In the present paper, we describe an approach to extend this result to three dimensional cooling. The vertical cooling requires that the horizontal oscillation couples with the vertical oscillation. For achieving horizontal-vertical coupling, a solenoid in electron beam cooling apparatus is utilized with an experiment (Qx=2.07,Qy=1.07). For various solenoidal magnetic fields from 0 to 40Gauss, horizontal and vertical betatron tunes are measured by beam transfer function. For a certain region of the solenoidal magnetic field, these tunes are mixed up each other. By optimization of such a coupling, we aim to proceed to three dimensional laser cooling.
* H. Okamoto Phys. Rev. E 50, 4982 (1994)
** H. Souda et.al.,contribution to this conference
Kyoto ICR, Uji, Kyoto
MPI-K, Heidelberg
Kyoto IAE, Kyoto
HU/AdSM, Higashi-Hiroshima
NIRS, Chiba-shi
JINR, Dubna, Moscow Region
Experiments of transverse laser cooling for 24Mg+ beam have been performed at the small ion storage and cooler ring, S-LSR. It is predicted that the longitudinal cooling force is transmitted to the horizontal direction with synchro-betatron coupling at the resonant condition*. The laser system consists of a 532nm pumping laser, a ring dye laser with variable wavelength around 560nm, and a frequency doubler. The horizontal beam size and the longitudinal momentum spread were optically measured by a CCD and a PAT (Post Acceleration Tube) respectively**, ***. The CCD measures the beam size by observing spontaneous emission from the beam and records in sequence of 100ms time windows the development of the beam profile. The time variation of the beam size after beam injection indicates the transverse cooling time. The initial horizontal beam size, which was about 1mm, was decreased by 0.13mm in 1.5s. The longitudinal momentum spread measured by PAT is increased at the resonant condition. This suggests transverse temperature was transferred to longitudinal direction by synchro-betatron coupling. Both measurements denote the horizontal cooling occurred only in the resonant condition ****.
* H. Okamoto, Phys. Rev. {E50}, 4982 (1994)
** M. Tanabe et. al, Appl. Phys. Express 1 (2008) 028001
*** T. Ishikawa Master Thesis, Kyoto Univ.(2008)
**** H. Souda et. al., contribution to IPAC10.
Kyoto ICR, Uji, Kyoto
NIRS, Chiba-shi
S-LSR is a compact ion storage and cooler ring to inject beam of the 7MeV proton and the 40MeV Mg+. The average vacuum pressure measured by the vacuum gauges without beam was achieved up to about 4x10-9 Pa in 2007. Many experiments have been carried out using the proton and Mg beam, for example the one-dimensional beam ordering of protons utilizing the electron cooler, the extraction tests of the short bunched beam and the laser cooling for the Mg beam had been performed. The beam lifetime can be estimated with the vacuum pressure or the loss-rate of the beam energy. The values of the estimated lifetime are nearly equal to the measured lifetime values. The present status of the proton beam lifetime and the vacuum pressure is reported.
Fermilab, Batavia
AAntiprotons in Fermilab's Recycler ring are cooled by a 4.3 MeV, 0.1 ' 0.5 A DC electron beam (as well as by a stochastic cooling system). The unique combination of the relativistic energy (γ = 9.49), an Ampere - range DC beam, and a relatively weak focusing makes the cooling efficiency particularly sensitive to ion neutralization. A capability to clear ions was recently implemented by way of interrupting the electron beam for 1-30 μs with a repetition rate of up to 40 Hz. The cooling properties of the electron beam were analyzed with drag rate measurements and showed that accumulated ions significantly affect the beam optics. For a beam current of 0.3 A, the longitudinal cooling rate was increased by factor of ~2 when ions were removed.
BNL, Upton, Long Island, New York
We report recent progresses on analytical studies of Coherent Electron Cooling. The phase space electron beam distribution obtained from the 1D FEL amplifier is applied to an infinite electron plasma model and the electron density evolution inside the kicker is derived. We also investigate the velocity modulation in the modulator and obtain a closed form solution for the current density evolution for infinite homogeneous electron plasma.
TRIUMF, Vancouver
The ISAC accelerators presently deliver various stable and radioactive CW heavy ion beams to experiments with energies ranging from 2keV/u up to about 4.5 MeV/u ( for A/q = 6 ). Beam intensities also vary enormously being as low as a few hundred ions per second for certain radioactive ion species and as high as 100 enA for stable and pilot beams. Monitoring of beams with currents of less than ~0.5 epA requires a dedicated diagnostics instrumentation which typically makes use of radiation hard single particle detectors. Several such devices have been built and are under development at TRIUMF. Electron multiplier based SEEM monitors, solid state and scintillator detectors with a count rate capability in excess of 106 pps are employed. Device controls are integrated into the EPICS environment and provide standardized, simple and transparent operation. Details of the design, tests and beam measurements will be present.
HIP, University of Helsinki
Comenius University in Bratislava, Faculty of Mathematics Physics and Informatics, Bratislava
Helsinki University, Department of Physics, University of Helsinki
The Super-FRS is a superconducting fragment separator that will be built as part of the FAIR facility. For the slow-extraction part of the beam diagnostics system a total of 32 detectors are needed for beam monitoring and for tracking and characterization of the produced ions. Since GEM-TPC detectors can perform over wide dynamic range without disturbing the beam, they are suitable for this kind of in-beam detection. We have studied the performance of a prototype GEM-TPC. The current status of the prototype detector and the measurement results are shown.
MPI-K, Heidelberg
Kyoto ICR, Uji, Kyoto
A cryogenic storage ring (CSR) is under construction at MPI für Kernphysik, which will be a unique facility for low velocity phase space cooled ion beams. Among other experiments the cooling and storage of molecular ions in there rotational ground state is planed. To meet this requirement the ring must provide a vacuum with a residual gas density below 10000 molecules/cm3, which will be achieved by cooling the vacuum chamber of the ion beam to 2-10 K. The projected stored beam current will be in the range of 1 nA - 1 μA. The resulting low signal strengths on the beam position pickups, current monitors and Schottky monitor put strong demands on these diagnostics tools. The very low residual gas density of the CSR does not allow using a conventional residual gas monitor to measure the profile of the stored ion beam. Other methods were investigated to measure the profile of a stored ion beam. In the paper an overview of the CSR diagnostics tool and diagnostics procedures will be given.
NIRS, Chiba-shi
For the beam profile diagnosis of heavy ion cancer therapy in HIMAC (Heavy Ion Medical Accelerator in Chiba), a MWPC (Multi-Wire Proportional Counter) detector is employed as a beam profile monitor. Due to the high rate beams (~ 108 pps), a gain reduction of output signals, which is caused by space charge effects, have been observed in the scanning beam experiments at HIMAC. In order to reduce the gain reduction by optimizing the parameters of MWPCs including anode radius, and distance between electrodes, a numerical calculation code was developed by employing two-dimensional fluid model. In order to understand the relations between the gain reduction and space charge distribution, the temporal evolution of the ion/electron distribution were calculated for several hundredμseconds, which is significantly longer than the time period required for ions to travel between the electrodes. The output signal was also evaluated by the current flux into the anode and compared with that obtained by the beam experiment at HIMAC. The dependence of the gain reduction on the MWPC parameters was analyzed from these calculation results.
JAEA/TARRI, Gunma-ken
It is important to match the injection beam emittance to the acceptance of an accelerator for high beam transmission A system to evaluate transverse beam matching has been developed in the JAEA AVF cyclotron facility. In this presentation, concepts of an apparatus for transverse acceptance measurement will be reported. The apparatus consists of a phase-space collimator in the injection beam line and beam current monitor after the cyclotron. The collimator consists of two pairs of position defining slits and angle defining slits to inject an arbitrarily small portion of transverse phase-space into the cyclotron. Measurement of the acceptance is made by testing every portion in the whole phase-space, which should large enough to cover the acceptance. The acceptance can be estimated from the sum of the portions of the beam which passes through the system.
J-PARC, KEK & JAEA, Ibaraki-ken
AEC, Chiba
Morimoto Engineering, Iruma, Saitama
NIRS, Chiba-shi
KEK, Ibaraki
Kyoto University, Radioisotope Research Center, Kyoto-shi
A nondestructive beam profile monitor using a nitrogen-molecule gas-jet sheet has been developed for intense ion beams. The density of the gas-jet sheet corresponds to 1 x 10-3 Pa. A light emitted from nitrogen excited by an ion beam collision is measured with a high sensitive camera attached a radiation hard image intensifier. In tests, beam profiles of 6 MeV/u full-stripped oxygen beams whose peak current was 600 μA. were measured. This paper describes characteristics of the instruments and the beam test results.
J-PARC, KEK & JAEA, Ibaraki-ken
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken
A single-wire proportional counter which has the maximum gain of 6·104 is used as a beam loss monitor (p-BLM), thus low-level beam loss can be monitored. However, it involves gain reduction problem by the space charge effect. It is essential to estimate the space charge effect to utilize a proportional counter for beam loss monitoring. The calibration procedure is discussed for the p-BLMs for 3-50BT and MR. Measurements of residual dose were made and some nuclei were identified. Radiation from the short-life nucleus, Fe53 (T1/2=8.51m), may be a good index to predict a residual dose after a long term beam operation.
JAEA, Rokkasho, Kamikita, Aomori
NIFS, Gifu
Tohoku University, School of Engineering, Sendai
Doshisha University, Graduate School of Engineering, Kyoto
We propose a negative ion beam probe system as a new scheme to diagnose beam profile of high power positive ion beams. Two RF linacs of IFMIF have to drive the neutron source by providing continuous-wave (CW) positive deuterium ion beams with the intensity of 125 mA each at the beam energy of 40 MeV. During the CW beam operations, the extreme intensity of the beam and the severe radiation levels make the beam diagnostics with conventional techniques in the transport lines terribly difficult. A beam of negative ions liable to lose the additional electron at the occasion of impact with a high energy particle can work as a probe to measure the positive ion beam profile. On possible configuration to achieve high intensity beam profile measurement is to inject a negative ion probe beam into the target beam perpendicularly, and measure the attenuation of the negative ion beam by beam-beam interaction at each position. We have started an experimental study for the proof-of-principle of the new beam profile monitoring system. The paper presents the status quo of this beam profile monitor system development and the prospects to apply the system to the IFMIF beam line controls.
JAEA/J-PARC, Tokai-mura
KEK, Ibaraki
JAEA, Ibaraki-ken
A wire scanner monitor (WSM) is one of essential measurement devices for beam commissioning of current accelerators. J-PARC Linac also employs a number of WSMs for transverse beam profile. The transverse matching is performed based on the measured beam width. In addition, we have tried to measure halo component with the BSMs. In this paper, we present the experimental results obtained in a beam study to characterize the operational performance of the WSM.
KNU, Deagu
Kyungpook National University, Daegu
PAL, Pohang, Kyungbuk
The synchrotron-radiation interferometer was employed for the beam size measurement of electron beam circulating in the storage ring at 2.5 GeV Pohang Light Source. We measured the beam sizes in both vertical and horizontal directions as function of stored beam current. In this presentation, we will discuss the interferometer system, analysis method for the measurement and the measured results. We also compared the measured beam sizes with predicted values from the lattice parameters in the ring.
ITEP, Moscow
Application of a plasma lens to focusing of ion beams has a number of essential advantages. It is important that the focusing capabilities of the lens depend on the stage of plasma development. Under certain conditions a magnetic field is linear, that allow to focus the beam to a very small spot. In other conditions, the magnetic field is nonlinear, that allow formation of hollow and other beam structures. Hollow cylinder-shaped beams of high energetic heavy ions are efficient drivers for implosion targets to create matter in a highly compressed state. The work deals with the study the possibility of using a plasma lens to transformation the density distribution of ions in the beam. Calculations and measurements were performed for a C6+ and Fe26+ beams of 200 MeV/a.u.m. energy. The obtained results and analysis are reported.
RAS/INR, Moscow
Bunch shape monitors with low energy secondary electrons transverse modulation have found a use for measurements of longitudinal distribution of charge in bunches for ion linear accelerators. Temporal bunch structure is coherently transformed into the spatial distribution through transverse rf scanning. The fields of the analyzed beam can influence the trajectories of the secondary electrons thus resulting in a distortion of the transformation and hence to a deterioration of measurement accuracy revealed in worsening of a phase resolution and in appearance of an error of phase reading. The first error component aggravates observation of the bunch fine structure. The second one distorts the measured shape of the bunch as a whole. Two models have been used for the effect analysis. In the first model a target potential of the bunch shape monitor is supposed to be undistorted by the analyzed beam space charge. In the second model a target potential is completely defined by the potential of the analyzed beam bunch. The applicability of the two models is discussed. The results of simulations for typical beam parameters are presented for the latest bunch shape monitor elaborations.
CERN, Geneva
As part of the CERN LHC injector chain upgrade, LINAC4 will accelerate H- ions from 45 keV to 160 MeV. A movable diagnostics test bench will be used to measure the beam parameters during the different construction stages (at 45 keV, 3 MeV and 12 MeV) at first in a laboratory setup and later in the LINAC4 tunnel. Given the beam properties at 3 and 12 MeV, the existing slit-grid system developed for the measurement of the transverse emittance at the source (45 keV) cannot be reused at these higher energies. At 3MeV and above the energy deposition would damage the steel slit in a single LINAC4 pulse. For this reason a new slit has been designed following detailed analytical and numerical simulations for different materials and geometries. The energy deposition patterns as simulated by FLUKA for the different cases are presented in detail. In addition, the choice of SEM grid wires for achieving the required measurement accuracy in terms of material, diameter and spacing, are discussed.
CERN, Geneva
SLAC, Menlo Park, California
The University of Liverpool, Liverpool
Synchrotron radiation is currently used on LHC for beam imaging and for monitoring the proton population in the 3 microsecond abort gap. In addition to these existing detectors, a study has been initiated to provide longitudinal density profiles of the LHC beams with a high dynamic range and a 50ps time resolution. This would allow for the precise measurement both of the bunch shape and the number of particles in the bunch tail or drifting into ghost bunches. A solution is proposed based on counting synchrotron light photons with two fast avalanche photo‐diodes (APD) operated in Geiger mode. One is free‐running but heavily attenuated and can be used to measure the core of the bunch. The other is much more sensitive, for the measurement of the bunch tails, but must be gated off during the passage of the core of the bunch to prevent the detector from saturating. An algorithm is then applied to combine the two measurements and correct for the detector dead time, after pulsing and pile‐up effects. Initial results from laboratory testing of this system are described in this paper.
The University of Liverpool, Liverpool
MPI-K, Heidelberg
Cockcroft Institute, Warrington, Cheshire
Supersonic gas-jets have attracted much interest as experimental targets in several fields of science since they combine low internal temperatures with high directionality. Axisymmetric jets have found widespread application, triggering a wealth of studies on their properties, while only a limited number of detailed studies have been done on planar jets. In this paper, the design of a beam profile monitor based on a planar supersonic gas-jet for use in the Ultra-low energy Storage Ring (USR) at the Facility for Antiproton and Ion Research (FAIR) in Germany is described. Optimization of the monitor requires investigation into different characteristic jet parameters. For that purpose extensive simulation work with the Gas Dynamics Tool (GDT) was done. The results of these studies are presented together with a description of a novel nozzle-skimmer configuration and an experimental test stand to benchmark the numerical results.
ORNL, Oak Ridge, Tennessee
ORNL RAD, Oak Ridge, Tennessee
A laser wire system* has been developed in the Spallation Neutron Source (SNS) superconducting linac (SCL). The SNS laser wire system is the world largest of its kind with a capability of measuring profiles of an operational hydrogen ion (H-) beam at each of the 23 cryomodule stations along the SCL by using a single light source. Presently 9 laser wire stations have been commissioned that measure profiles of the H- beam at energy levels from 200 MeV to 1 GeV. The laser wire diagnostics has no moving parts inside the beam pipe and can be run parasitically on a neutron production H- beam. This talk reports our recent study of the laser wire profile measurement performance. Parasitic profile measurements have been conducted at multiple locations of SCL on an operational one-megawatt neutron production beam that SNS recently achieved as a new world record. We will describe experimental investigations of the laser wire system performance including the stability and repeatability of the measurement and the influence of the laser parameters. We will also discuss novel beam diagnostics capabilities at the SNS SCL by using the laser wire system.
* Liu et al., "Laser wire beam profile monitor in the SNS superconducting linac," Nucl. Instr. and Meth. A, to appear.
BNL, Upton, Long Island, New York
The Relativistic Heavy Ion Collider (RHIC) operates with either ions or polarized protons. After increasing the heavy ion luminosity by two orders of magnitude since its commissioning in 2000, the current luminosity upgrade program aims for an increase by another factor of 4 by means of 3D stochastic cooling and a new 56 MHz SRF system. An Electron Beam Ion Source is being commissioned that will allow the use of uranium beams. Electron cooling is considered for collider operation below the current injection energy. For the polarized proton operation both luminosity and polarization are important. In addition to ongoing improvements in the AGS injector, the development of a new high-intensity polarized source has started. In RHIC a number of upgrades are under way to increase the intensity and polarization transmission to 250 GeV beam energy. Electron lenses will be installed to partially compensate the head-on beam-beam effect.
CEA, Gif-sur-Yvette
An important issue for the new high power class ion linac projects is the preservation of the beam quality through the acceleration in the linac. An extremely low fraction of the beam (from 10-4 down to 10-7) is sufficient to complicate the hands on maintenance in such accelerator. This paper reviews the theory and the codes for the design and simulation of MW ion linacs. Basics rules for the definition of their architecture and the results applied to existing machines and projects are covered.
GSI, Darmstadt
Non-destructive profile measurements are preferred not only for single-pulse diagnostics at different locations in a transfer line, but also to enable time resolved observations of stored the beam within a synchrotron. Moreover, the large beam power available at modern hadron accelerators excludes intersecting materials like screens, SEM-grids or scanners. Over the last years advanced concepts were realized: Ionization profile monitors are based on residual gas ionization and their spatially resolved detection. A complimentary method uses single photons detection of beam induced residual gas excitation. A third method is based on the deflection of a crossing electron beam to reconstruct the beam's transverse distribution. At LINACs for negative hydrogen acceleration, a scanning laser beam combined with a photo-electron detector was developed. The transverse profile can be monitored by means of a dedicated pick-up for the determination of the beam's quadrupole moment, i.e. the difference of the horizontal and vertical beam variance. The physical principles and technical realizations of these monitors are discussed.
Fermilab, Batavia
As the Fermilab Tevatron Collider program draws to a close, a strategy has emerged of an experimental program built around the high intensity frontier. The centerpiece of this program is a superconducting H- linac that will support world leading programs in long baseline neutrino experimentation and the study of rare processes. Based on technology shared with the International Linear Collider, Project X will provide multi-MW beams at 60-120 GeV from the Main Injector, simultaneous with very high intensity beams at lower energies. Project X also supports development of a Muon Collider as a future facility at the energy frontier.
JINR, Dubna, Moscow Region
This presentation will describe the accelerators - basic facilities at JINR and briefly discuss research programs for applications and basic research, which are performed at these accelerators.
NIRS, Chiba-shi
AEC, Chiba
Based on more than ten years of experience of the carbon cancer therapy with HIMAC, we have proposed a new treatment facility for the further development of the therapy with HIMAC. This facility will consist of three treatment rooms: two rooms equipped with horizontal and vertical beam-delivery systems and one room with a rotating gantry. For the beam-delivery system of the new treatment facility, a 3D hybrid raster-scanning method with gated irradiation with patient's respiration has been proposed. A R&D study has been carried out toward the practical use of the proposed method. In the R&D study, we have improved the beam control of the size, the position and the time structure for the proposed scanning method with the irradiation gated with patient's respiration. Further, owing to the intensity upgrade of the HIMAC synchrotron, we can successfully extend the flattop duration, which can complete one fractional irradiation with one operation period. The building construction of the new treatment facility will be completed at March 2010 and treatment of 1st patient is scheduled at March 2011. We will report the recent progress on the new treatment facility project at HIMAC.
HU/AdSM, Higashi-Hiroshima
Hiroshima University, Higashi-Hiroshima
LLNL, Livermore, California
S-POD (Simulator for Particle Orbit Dynamics) is a tabletop, non-neutral plasma trap system developed at Hiroshima University for fundamental beam physics studies. The main components of S-POD include a compact radio-frequency quadrupole trap, various AC and DC power supplies, a vacuum system, a laser cooler, several diagnostics, and a comprehensive computer control system. A large number of ions, produced through the electron bombardment process, are captured and confined in the RFQ trap to emulate collective phenomena in space-charge-dominated beams traveling in periodic linear focusing lattices. This unique experiment is based on the isomorphism between a one-component plasma in the laboratory frame and a charged-particle beam in the center-of-mass frame. We here employ S-POD to explore the coherent betatron resonance instability which is an important issue in modern high-power accelerators. Ion loss behaviors and transverse plasma profiles are measured under various conditions to identify the parameter-dependence of resonance stopbands. Experimental observations are compared with PIC simulation results obtained with the WARP code.
MEPhI, Moscow
The undulator linear accelerator using electrostatic undulator (UNDULAC-E) is suggested as an initial part of high intensity ion linac*. In UNDULAC ion beam accelerating and focusing are realized by of the combined field of two non-synchronous harmonics. Indeed, the main factor limiting beam intensity in ion accelerator is a space charge force. There exist, at least, two ways to increase ion beam intensity: to enlarge the beam cross section and to use the space charge neutralization. The ribbon ion beam dynamics in UNDULAC-E was discussed in**. Accelerating force value in UNDULAC is proportional to squared particle charge and oppositely charged ions with the identical charge-to-mass ratio can be accelerated simultaneously within the same bunch and the beam space charge neutralization can be realized. These methods will be studied analytically and verified by numerical simulation for UNDULAC-RF in this paper.
*E.S. Masunov, Sov. Phys. ' Tech. Phys., 1990, v. 35 (8), pp. 962-965. **Masunov, S.M. Polozov. NIM A, 558 (2006), pp. 184-187.
PPPL, Princeton, New Jersey
To achieve high focal spot intensities in ion-beam-driven high energy density physics and heavy ion fusion applications, the ion beam must be compressed longitudinally by factors of ten to one hundred before it is focused onto the target. The longitudinal compression is achieved by imposing an initial velocity profile tilt on the drifting beam, and allowing the beam to compress longitudinally until the space-charge force or the internal thermal pressure stops the longitudinal compression of the charge bunch. In this paper, the problem of longitudinal drift compression of intense charged particle beams is analyzed analytically and numerically for the two important cases corresponding to a cold beam, and a pressure-dominated beam, using a one-dimensional warm-fluid model describing the longitudinal beam dynamics. The hodograph transformation is used to transform the nonlinear fluid equations into a single, second-order, linear partial differential equation (PDE). The general solution of this equation describing the intense beam system with stagnation point is analyzed and illustrated with several examples.
KEK, Ibaraki
RIKEN Nishina Center, Wako
An asymmetrical con-focal cavity is composed of tow concave mirrors with different focal length, placed face to face, and their axes and focal points coincide. When a laser beam is injected in parallel with the mirror axis, from backward of and just outside of the mirror with the smaller focal length, the laser beam is trapped in the cavity and repeats reflection by mirrors. Then, the beam reflected by the mirror with the larger focal length passes every time the focal point and the period by which pulses return to the focal point is constant. Therefore, if the repetition period of the injected laser pulse is equal to the repetition period in the cavity, all laser pulses comes to the focal point at the same time and the beam intensity is stacked up. Calculation on the performance of an asymmetrical con-focal cavity shows that a laser pulse can be recycled more than a few tens turns and the beam intensity can be stacked to more than a few tens times of the original beam intensity when the laser beam is a Gaussian beam and the reflectance of the mirrors is 100%. Results of calculation is examined using a He-Ne laser and a pair of high reflection mirrors.
GSI, Darmstadt
The heavy ion synchrotron SIS18 at the GSI facility will be upgraded by a dual harmonic RF acceleration system in the process of using SIS18 as booster for the future FAIR SIS100 accelerator. The dual harmonic mode will extend the SIS18 operating towards higher beam currents. As a part of a large LLRF upgrade at the synchrotron RF systems at GSI, new FPGA and DSP based electronics have been designed, built and commissioned. To prove the functionality of the LLRF equipment as well as the general dual harmonic topology, machine development experiments using the existing cavities have been performed. During these experiments, the main parameters of the control loop were determined. Additionally, the impact of RF gap voltage amplitude and phase variations onto the ion beam have been investigated, like e.g. creation of a dual harmonic bucket or fast changes in harmonic number. The experiments showed a high sensitivity of the ion beam to small deviations in the phase between both harmonics and thereby confirmed the requirements on the high precision regarding phase accuracy of the electronic setup especially for the closed loop phase control systems.
CERN, Geneva
The Low Energy Ion Ring (LEIR) is an accumulation ring in the Large Hadron Collider ion injector chain. After its successful start in 2005, it has been running in three operational campaigns. The LEIR LLRF system is the first all-digital low-level RF (LLRF) system to be made operational in a CERN circular machine. Composed of modular VME 64X hardware, it carries out extensive digital signal processing via Field Programmable Gate Arrays and Digital Signal Processors. System capabilities include beam control tasks, such as frequency program, beam phase, radial and synchronization loops, as well as cavity voltage/phase loops. All the system's control parameters are fully configurable, remotely and in-between cycles; extensive built-in diagnostics and signal observation features are available. The system has proven to be not only flexible and powerful but also extremely reliable. This is very important as the LEIR LLRF system is the pilot project for the LLRF renovation of other CERN's machines. This paper gives an overview of the main system building blocks and outlines their capabilities and operational features, along with results obtained during the first years of beam operation.
CASA, newport news
JLAB, Newport News, Virginia
A unique design feature of a polarized Medium Energy Electron-Ion Collider (MEIC) based on CEBAF is its 'Figure-8' storage rings for both electrons and ions, which significantly simplifies beam polarization maintenance and manipulation. While electron (positron) polarization is maintained vertical in arcs of the ring, a stable longitudinal spin at four collision points is achieved through solenoid based spin rotators and horizontal orbit bends. The proposed MEIC lattice was developed in order to preserve a very high polarization (more than 70%) of the electron beams injected from the CEBAF machine. The otherwise coupled beam trajectory due to solenoids used in the spin rotators was decoupled by design. Aspin matching technique needs to be implemented in order to enhance quantum self-polarization and minimize depolarization effects.
BNL, Upton, Long Island, New York
The luminosity of a ring-ring electron-ion collider is limited by the beam-beam effect on the electrons. Simulation studies have shown that for short ion bunches this limit can be significantly increased by head-on beam-beam compensation via an electron lens. However, due to the large beam-beam parameter experienced by the electrons, together with an ion bunch length comparable to the beta-function at the IP, electrons perform a sizeable fraction of a betatron oscillation period inside both the long ion bunches and the electron lens. Recent results of our simulation studies of this effect will be presented.
BNL, Upton, Long Island, New York
A fast transition instability presents a limiting factor for ion beam intensity in RHIC. Several pieces of evidence show that electron clouds play an important role in establishing the threshold of this instability. In RHIC Runs 7 and 8 dedicated measurements of the instability, using different beam instrumentation tools (Button BPM, Wall Current Monitor, transition monitors) were done in order to observe the instability development over hundreds turns. The papers presents and discusses the results of those measurements in time and frequency domains.
CERN, Geneva
The beam profile screens in the long SPS to LHC transfer lines were used to measure with high precision the emittance growth arising from scattering. The effective thickness of the scatterer could be varied by adding thick Al2O3 fluorescent screens, with the emittance measurement made using very thin Ti OTR screens. The technique allows the intrinsic variation in the emittance from the injector chain to be factored out of the measurement, and was applied to Pb82+ and protons, both with 450 GeV rigidity. The results are presented and the possible applications to the accurate benchmarking of nuclear interaction codes discussed.
BNL, Upton, Long Island, New York
Booster extraction presents a number of problems that include strengths and waveforms of the pulsed magnets and design of the vacuum chamber. Instabilities in the booster extraction may compromise the extracted beam quality deteriorating value of high-performance injector design. Here we discuss requirements and tolerances for the extraction system components and methods of increasing its performance.
BNL, Upton, Long Island, New York
We present our studies on various aspects of the beam dynamics in 'racetrack' design of the first stage electron-ion collider at RHIC (eRHIC), including transverse beam break up instabilities, electron beam emittance growth and energy loss due to synchrotron radiation, electron beam losses due to Touschek effects and residue gas scattering, beam-beam effects at the interaction region and emittance growth of ion beam due to electron bunch to bunch noises. For all effects considered above, no showstopper has been found.
TEMF, TU Darmstadt, Darmstadt
GSI, Darmstadt
For the future operation as an injector for the FAIR project the SIS18 synchrotron has to deliver intense and high quality ion bunches with high repetition rate. One requirement is that the initial momentum spread of the injected coasting beam should not exceed the limit set by the SIS18 rf bucket area. Also the Schottky spectrum should be used to routinely measure the momentum spread and revolution frequency directly after injection. During the transverse multi-turn injection the SIS18 is filled withμbunches from the UNILAC linac at 36 MHz. For low beam intensities theμbunches debunch within a few turns and form a coasting beam with a Gaussian-like momentum spread distribution. With increasing intensity we observe persistent current fluctuations and an accompanying pseudo-Schottky spectrum. We will explain that the multi-stream instability of theμbunch filaments is responsible for the turbulent current spectrum that can be observed a few 100 turns after injection. The current spectrum observed in the SIS18 and the results from a longitudinal simulation code will compared to an analytical model of the multi-stream instability induced by the space charge impedance.
TEMF, TU Darmstadt, Darmstadt
GSI, Darmstadt
Electron clouds generated by residual gas ionization pose a potential threat to the stability of the circulating heavy ion beams in the existing SIS-18 synchrotron and in the projected SIS-100. The electrons can potentially accumulate in the space charge potential of the long bunches. As an extreme case we study the accumulation of electrons in a coasting beam under conditions relevant in the SIS-18. Previous studies of electron clouds in coasting beams used Particle-In-Cell (PIC) codes to describe the generation of the cloud and the interaction with the ion beam. PIC beams exhibit much larger fluctuation amplitudes than real beams. The fluctuations heat the electrons. Therefore the obtained neutralization degree is strongly reduced, relative to a real beam. In our simulation model we add a Langevin term to the electron equation of motion in order to account for the heating process. The effect of natural beam fluctuations on the neutralization degree is studied. The modification of the beam response function as well as the stability limits in the presence of the electrons is discussed. Finally we will also address the electron accumulation in long bunches.
TUB, Beijing
Tsinghua University, Beijing
HU/AdSM, Higashi-Hiroshima
LBNL, Berkeley, California
JAEA/TARRI, Gunma-ken
During the beam crystallization process, the main heating source is Intra-beam scattering (IBS), in which the Coulomb collisions among particles lead to a growth in the 6D phase space volume of the beam. The results of molecular dynamics (MD) simulation have shown an increase of heating rate as the temperature is increased from absolute zero, but then a peak in the heating rate, and subsequent decrease with ever increasing temperature*. This phenomenon has been carefully studied by Y. Yuri, H. Okamoto, and H. Sugimoto**. On the other hand, in the traditional IBS theory valid at high temperatures, heating rate is monotonically increasing as the temperature becomes lower***. In this paper we attempt to understand the "matching" at low temperatures between the MD results and traditional IBS theory, by including many body effects in the traditional IBS theory. In particular the Debye shielding is included. We shall present how the traditional theory is modified by shielding, and show how this effect improves the "matching" with the results from MD.
* J. Wei, H. Okamoto, and A. Sessler, Phys. Rev. Lett. 80, 2606
** Y.Yuri, H. Okamoto, and H. Sugimoto, J. Phys. Soc. Jpn. 78, 124501
***A. Piwinski, Lect. Notes Phys. 296, 297 (1988)
IMP, Lanzhou
Two electron cooling devices have been used at HIRFL-CSR in order to provide high quality heavy ion beams for nuclear and atomic research. The momentum spread is one of the most important characteristics of the beam quality. At HIRFL-CSR, the momentum spread is measured directly with the aid of longitudinal Schottky spectra system. In this paper, the measurements for various ion species are presented. At relatively high intensity, longitudinal Schottky spectra is double peak due to collective phenomena and the momentum spread can be obtained by fitting the spectra. The dependence of momentum spread on stored particle number is proportional to N**a. Moreover, the heating factor was investigated after switching off the electron cooling. The residual gas scattering, the intrabeam scattering and instabilities are studied according to the measured data.
MPI-K, Heidelberg
GSI, Darmstadt
JINR, Dubna, Moscow Region
Cockcroft Institute, Warrington, Cheshire
Electrostatic storage rings have proven to be invaluable tools for atomic and molecular physics. Due to the mass independence of the electrostatic rigidity, these machines are able to store a wide range of different particles, from light ions to heavy singly charged bio-molecules. However, earlier measurements showed strong space charge limitations; probably linked to non-linear fields that cannot be completely avoided in such machines. The nature of these effects is not fully understood. In this contribution, we present the results from simulating an electrostatic storage ring under consideration of non-linear fields as well as space charge effects using the computer code SCALA.
SOLEIL, Gif-sur-Yvette
Ever since the commissioning times, transverse instabilities, which now have been identified as the so called Fast Beam-Ion Instability (FBII), have existed in the SOLEIL storage ring. Though along with the improvement of the vacuum level with increasing beam dose its relative importance has decreased to a large extent as compared to the classical instabilities due to the coupling impedance, the FBII still exists persistently at high current, making it difficult to attain a stable beam at the final goal of 500 mA. In particular, sudden beam losses are frequently encountered after keeping the beam stable over a certain time with transverse feedback at the final current, which raised a question as to whether the observed phenomena are compatible with the saturating effect of the FBII. Experimental analysis using the bunch by bunch feedback diagnostics as well as theoretical and numerical analysis using multibunch tracking have been carried out to understand the instability quantitatively and to elucidate the mechanism of the beam losses.
MPI-P, München
SINAP, Shanghai
SSRF, Shanghai
Fast ion instability has been observed in the early commissioning and operation of the Shanghai Synchrotron Radiation Facility (SSRF) storage ring. In this paper, a weak-strong code is used to simulate the fast ion instability in SSRF storage ring. Various fill patterns and gas pressures are investigated. The results show that the mini-train fill patterns are very effective to suppress the growth of the fast ion instability. By employing a fast feedback system, it is possible to damp the growth of beam oscillation amplitude below the beam size.
SLAC, Menlo Park, California
PEP-X, a next generation, ring-based light source is designed to run with beams of high current and low emittance. Important parameters are: energy 4.5 GeV, circumference 2.2 km, beam current 1.5 A, and horizontal and vertical emittances, 150 pm by 8 pm. In such a machine it is important that impedance driven instabilities not degrade the beam quality. In this report we study the strength of the impedance and its effects in PEP-X. For the present, lacking a detailed knowledge of the vacuum chamber shape, we create a straw man design comprising important vacuum chamber objects to be found in the ring, for which we then compute the wake functions. From the wake functions we generate an impedance budget and a pseudo-Green function wake representing the entire ring, which we, in turn, use for performing instability calculations. In this report we consider in PEP-X the microwave, transverse mode-coupling, multi-bunch transverse, and beam-ion instabilities.
BNL, Upton, Long Island, New York
In this paper, we present an overview of the impact of collective effects upon the performance of the NSLS-II booster.
BNL, Upton, Long Island, New York
Case Western Reserve University, Center for Synchrotron Biosciences, Upton, New York
Stony Brook University, Stony Brook
The diamond amplified photocathode has the potential to dramatically increase the average current available from photoinjectors, perhaps to the amphere-class performance necessary for flux-competitive fourth-generation light sources. Electron emission from a diamond amplifier has been observed from hydrogen-terminated diamond, using both photons and electrons to generate carriers. The diamond electron amplifier has been demonstrated, with an emission gain of 40. Very high average current densities (>10 A/cm2) have been transported through the diamond using x-ray generated carriers. The device relies on high-purity intrinsic diamond with low crystalline defect density, as well as a negative electron affinity achieved by hydrogen termination. The effects of diamond purity and crystalline defects on charge transport in the material, and emission from the diamond surface have been studied using a number of techniques and the process is now well understood. The electron affinity of diamond has been measured to be -1.1 eV; the fraction of the electrons produced in the material which are emitted from the surface has also been measured.
JAEA/Kansai, Kyoto
Kyoto Univeristy, Kyoto
Interactions of x-ray free electron laser (XFEL) light with a single cluster target are numerically investigated. The irradiation of XFEL light onto material leads to the ionization of the target by photo-ionization and generation of high energy electrons. This results in the further ionization via Auger effect, collisional ionization, and field ionization. The ionization rate or time scale of each process depends on the condition of XFEL (intensity, duration, photon energy) and target size. In order to understand the ionization dynamics, we used a three-dimensional Particle-in-Cell code which includes the plasma dynamics as well as relevant atomic processes such as photo-ionization, the Auger effect, collisional ionization/relaxation, and field ionization. It is found that as the XFEL intensity increases to as high as roughly 1021 photons/pulse/mm2, the field ionization, which is the dominant ionization process over the other atomic processes, leads to rapid target ionization. The target damage due to the irradiation by XFEL light is numerically evaluated, which gives an estimation of the XFEL intensity so as to suppress the target damage within a tolerable range for imaging.
* T. Nakamura, et al., Phys. Rev. A, vol. 80, 053202 (2009)
SLAC, Menlo Park, California
Simulations of ion migration in the LCLS RF gun and injector A. Brachmann On behalf of the LCLS commissioning team The motivation for this work was the observed surface contamination of the first LCLS RF gun copper cathode. We will present the results of simulations in regards to ion migration in the LCLS gun. Ions of residual gases will be created by interaction of molecular gas species with the UV drive laser beam and by the electron beam itself. The larger part of those ionized molecules remain in the vicinity of creation, are transported towards beam line walls or away from the cathode. However a significant fraction gains enough kinetic energy to be focused by RF and magnetic fields, reaching the cathode and producing an undesirable increase of the cathode's surface work function. Although this fraction is small, during long term operation, this effect becomes a significant factor limiting the source performance.
HU/AdSM, Higashi-Hiroshima
JAEA/ERL, Ibaraki
KEK, Ibaraki
A NEA-GaAs photocathode is an important component for the next generation light source based on the ERL. Although the NEA-GaAs cathode has high quantum efficiency, deterioration of the NEA surface becomes serious with a high current operation. Therefore improvement of a vacuum in the cathode chamber is essential to get a long lifetime of the NEA-GaAs cathode. We are developing a photocathode test bench consisting of titanium (TP340) chamber, whose outgas rate is 1/1000 smaller than one of a SUS chamber, a cryo-pump (4000l/s) and a NEG pump (1900l/s). We report mainly the vacuum performance of the system.
GSI, Darmstadt
The FAIR accelerator project at GSI should increase the intensity of primary proton and heavy ion beams by up to two orders of magnitude, relative to the existing GSI facility. In addition to the design of the new synchrotron SIS-100 and the storage rings, the intensity upgrade of the SIS-18 synchrotron plays a key role for the FAIR project. Recently a new record beam intensity for intermediate charge state uranium ions has been achieved in the SIS-18. Still several challenges related to beam intensity effects and phase space conservation have to be mastered in order to reach the beam parameters required for the injection into SIS-100. In SIS-100 beam loss control and machine protection are of major concern. Lost energetic heavy ions can cause a more severe damage of accelerator components than the corresponding amount of protons. Gradual beam loss of energetic ions is expected to occur in SIS-100 mainly during slow extraction of intense beams. Coherent transverse instabilities induced by the beam pipe impedance are a potential cause of fast beam loss and emittance increase. Cures and protection measures together with the result of simulation studies will be summarized.
Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Elektronen-Speicherring BESSY II, Berlin
PTB, Berlin
The Metrology Light Source* is the first storage ring optimized for THz generation**. It applies a bunch shortening mode, based on a flexible momentum compaction factor 'alpha'. The emitted THz radiation is very sensitive to the machine tuning, its power could vary by many orders of magnitude. We report on coherent THz signal intensities as a function of different machine parameters, such as beam energy, beam current, rf voltage and alpha tuning.
* R. Klein et al., Phys. Rev. ST. Accel. Beams vol. 11, 110701 (2008). ** J. Feikes et al., The Metrology Light Source: The First Electron Storage Ring Optimized for Generating Coherent THz Radiation, submitted to Phys. Rev. ST. Accel. Beams (2009).
NSC/KIPT, Kharkov
The status of X-ray generator NESTOR that is under construction in Kharkov Institute of Physics and Technology is described in the paper.
PKU/IHIP, Beijing
A compact remote control system with the SIMATIC S7-300 PLC is being designed for Peking University Neutron Imaging FaciliTY (PKUNIFTY). PKUNIFTY consists of a 2.45GHz ECR Deuteron ion source, LEBT, a 201.5MHz RFQ cavity, HEBT and Be target. Now PLC control system for ECR ion source and LEBT has been completed and tested. This paper will present the structure of the control system, the HMI with useful data recording system, and some measures took to improve the system safety.
Cosylab, Ljubljana
GSI, Darmstadt
Present GSI control system uses an in-house developed CORBA based middleware called IFC. For FAIR project that will be build on the GSI site, a new control system is foreseen. New devices that are being integrated into the control system preferably will be developed in FESA. In this article, an IFC to FESA gateway will be presented. The gateway provides an intermediate layer that is able to talk to FESA device servers on one side and provide their functionality to existing IFC clients. The gateway will allow coexistence of FESA front-end implementations and existing GSI device servers, providing a smooth transition path to the future FAIR front-end environment. New GSI and FAIR devices that will be implemented in FESA will have to match GSI standards for nomenclature and device modeling. Exact match of new devices is not possible due to different hardware and software architecture of the new system, therefore a gateway solution is required. The gateway can translate the complete device model, including conversion from FESA to GSI data types. In the process of gateway design and implementation, valuable input was collected for the design of the future FAIR control system.
DELTA, Dortmund
A stable beam orbit is essential for safe operation of particle accelerators. This applies to electron machines and even more to hadron machines running high beam currents. Based on developments at DELTA, basic designs of fast orbit feedbacks systems for the FAIR rings SIS18 and HESR (planned) and COSY at the Forschungszentrum Jülich are presented.
KEK, Ibaraki
Sokendai, Ibaraki
In development of superconducting radio-frequency niobium cavities, there are problems in low performances of electro-polished (EP) cavities with a fresh EP solution due to stains on the surfaces with discoloration. Although the stain problems have been known from the past researches, the detailed study with surface analysis has not been carried out. In this study, the stains on the niobium surfaces were observed with x-ray photoelectron spectroscopy (XPS), Auger electron spectroscopy and scanning electron microscope. According to results of XPS, there are some differences in atomic components at the stained and non-stained surfaces, ex, a little amount of fluorine and no metal oxide were found only at the stained surface. In this article, we will describe the detail of the XPS results.
KEK, Ibaraki
Sokendai, Ibaraki
We have constructed an Electro-polishing (EP) Facility in the Superconducting RF Test Facility (STF) at KEK in 2008. The EP facility has been used for the EP process of Superconducting RF (SRF) 9-cell cavities for more than one year. In the EP facility, the capacity of the EP-electrolyte reservoir tank is 2,000 L. This size is relatively large if compared with EP facilities in other laboratories. It means that the quality control of EP electrolyte is more difficult because the status of EP-electrolyte changes as the aging of EP-electrolyte proceeds. In the real EP-process operations, we circulated the EP electrolyte of 1,100 L which was firstly delivered into the tank in January 2008 and was disposed in May 2009. During this period, we performed the EP processes 40 times and periodically measured the concentration of Nb ,Al ,HF in the EP electrolyte. In this article, we report the detailed results of the EP-electrolyte monitoring as well as the observation of changing electronic current oscillation in the EP processes during this period in the EP facility at STF/KEK.
Peking University, School of Physics, Beijing
PKU/IHIP, Beijing
This paper introduce a possible solution to improve the efficiency of the very low beta SC accelerating structure, via extending the gaps number of 4-gap interdigital QWR by doubling its stems number. The new cavity is a 8-gap QWR, which is comprised of two parallel TEM resonant lines operating in opposing phase from each other. It maintains the 4-gap QWR's good EM parameters and enables the use of demountable flange. The more important advantage is the potential improvement of efficiency. According to a preliminary estimation of longitudinal dynamics, the 8-gap QWR could stably accelerate heavy ion at the velocities 0.01<v/c<0.05.
Cockcroft Institute, Lancaster University, Lancaster
JLAB, Newport News, Virginia
The planned luminosity upgrade to LHC is likely to necessitate a large crossing angle and a local crab crossing scheme. For this scheme crab cavities align bunches prior to collision. The scheme requires at least four such cavities, a pair on each beam line either side of the interaction point (IP). Upstream cavities initiate rotation and downstream cavities cancel rotation. Cancellation is usually done at a location where the optics has re-aligned the bunch. The beam line separation near the IP necessitates a more compact design than is possible with elliptical cavities such as those used at KEK. The reduction in size must be achieved without an increase in the operational frequency to maintain compatibility with the long bunch length of the LHC. This paper proposes a suitable superconducting variant of a four rod coaxial deflecting cavity (to be phased as a crab cavity), and presents analytical models and simulations of suitable designs.
KEK, Ibaraki
Osaka University, Graduate School of Engineering, Osaka
RLNR, Tokyo
Magnets of the synchrotron accelerator which extracts the accelerated beams are excited by pulse operation power supply, and then the load fluctuation should be a severe problem. An energy storage system, such as SMES, fly-wheel generator so far, will be required for compensating the pulse electric power, and reducing the disturbances of the connected power line. The system is also expected to protect the instantaneous voltage drop and contributes the reliability of the storage ring. Present status of R & D and the features for the energy storage systems are discussed. The application of the energy storage systems to synchrotrons for the medical use is described. The compensation of the typical pulse electric power of the synchrotron for the cancer therapy is studied.
CERN, Geneva
The maximum tolerable pressure value in the chamber of the CLIC electron Main Linac is determined by the threshold above which the fast ion instability sets in over a bunch train. Instability calculations must take into account that, since the accelerated beam becomes transversely very small, its macroscopic electric field can reach values above the field ionization threshold. In this paper we first discuss threshold values of the electric field for field ionization and the extent of the transverse region that gets fully ionized along the ML. Then, we show the results of the instability simulations from the FASTION code using the new model, and consequently review the pressure requirement in the ML.
CERN, Geneva
INFN/LNF, Frascati (Roma)
CEA, Gif-sur-Yvette
Uppsala University, Uppsala
The objective of the CLIC Test Facility CTF3 is to demonstrate the key feasibility issues of the CLIC two-beam technology: the efficient generation of a very high current drive beam and its stable deceleration in 12 GHz resonant structures, to produce high-power RF pulses and accelerate the main beam with an accelerating gradient of 100 MV/m. The construction and commissioning of CTF3 has taken place in stages from 2003. Many milestones had already been reached, including the first demonstration at the end of 2009 of a factor 2 x 4 re-combination of the initial drive beam pulse, thus reaching a beam current of 25 A. In this paper we summarise the commissioning highlights and the issues already validated at the earlier stages. We then show and discuss the latest results obtained, in view of the completion of the CLIC feasibility demonstration due for the end of 2010.
Fermilab, Batavia
Muons, Inc, Batavia
IIT, Chicago, Illinois
ANL, Argonne
University of Chicago, Chicago, Illinois
Voss Scientific, Albuquerque, New Mexico
A high pressurizing hydrogen gas filled RF cavity has a great potential to apply for muon colliders. It generates high electric field gradients in strong magnetic fields with various conditions. As the remaining demonstration, it must work under high radiation conditions. A high intensity muon beam will generate a beam-induced electron swarm via the ionization process in the cavity. A large amount of RF power will be consumed into the swarm. We show the recent non-beam test and discuss the electron swarm dynamics which plays a key role to develop a high pressure RF cavity.
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire
Ion induced pressure instability is a potential problem for the ILC positron damping ring (DR)if the chosen pumping scheme does not provide sufficient pumping. The ion induced pressure instability effect results from ionisation of residual gas molecules by the beam particles, their acceleration in the field of the beam towards the vacuum chamber walls, causing ion induced gas desorption from vacuum chamber walls; these gas molecules in their turn can also be ionised, accelerated and cause further gas desorption. If the pumping is insufficient, this effect may cause a pressure instability, in which the pressure in the beam chamber grows rapidly to an unacceptable level. To analyse the ion induced pressure instability in the ILC positron DR the energy gained by ions was calculated for the appropriate beam parameters; it was found that the energy gain of ions will be about 300 eV. The ion induced gas desorption was estimated, and pumping solutions to avoid the ion induced pressure instability are suggested. The cheapest and most efficient solution is to use NEG coated vacuum chamber.
IMP, Lanzhou
CSR has recently made significant progress in commissioning a variety of light to heavy ion in the cooler ring. Also, carbon therapy was successfully carried out. A significant achievement is the energy modulation extraction using slow extraction realizing 3D conformal treatment.
HU/AdSM, Higashi-Hiroshima
Hiroshima University, Faculty of Science, Higashi-Hirosima
An ion plasma confined in a compact trap system is Coulomb crystallized near the absolute zero temperature. The emittance of the crystallized ion plasma is close to the ultimate limit, far below those of any regular ion beams. This implies that, if we can somehow accelerate a crystal without serious heating, an ion beam of extremely low emittance becomes available*. Such ultra-low emittance beams, even if the current is low, can be used for diverse purposes including precise single ion implantation to various materials and for systematic studies of radiation damage effects on semiconductors and bio-molecules. We performed proof-of-principle experiments on the extraction of Coulomb crystals from a linear Paul trap system developed at Hiroshima University. A string crystal of 40Ca+ ions is produced with the Doppler laser cooling technique and then extracted by switching DC potentials on the trap electrodes. We demonstrate that it is possible to transport the ultra-low temperature ion chain keeping its ordered configuration.
* M. Kano et al., J. Phys. Soc. Jpn. 73, No.3, 760 (2004).
SLAC, Menlo Park, California
A Marx-topology klystron modulator is under development for the International Linear Collider (ILC) project*. It is envisioned as a lower cost, smaller footprint, and higher reliability alternative to the present, bouncer-topology, baseline design. The application requires 120 kV (±0.5%), 140 A, 1.6 ms pulses at a rate of 5 Hz. The Marx constructs the high voltage pulse by combining, in series, a number of lower voltage cells. The Marx employs solid state elements; IGBTs and diodes, to control the charge, discharge and isolation of the cells. Active compensation of the output is used to achieve the voltage regulation while minimizing the stored energy. The developmental testing of a first generation prototype, P1, has been completed. This modulator has been integrated into a test stand with a 10 MW L-band klystron, where each is undergoing life testing. Development of a second generation prototype, P2, is underway. The P2 is based on the P1 topology but incorporates an alternative cell configuration to increase redundancy and improve availability. Status updates for both prototypes are presented.
* ILC Reference Design Report, http://www.linearcollider.org/cms/?pid=1000437
JAEA/J-PARC, Tokai-mura
KEK/JAEA, Ibaraki-Ken
KEK, Ibaraki
We have been operating the RF cavities loaded with MA cores with a high field gradient of more than 20 kV/m since October 2007. We have been measuring the RF cavity impedance at the shutdown periods, and we detected the impedance reductions of RCS RF cavities on January and June 2009. Taking out the RF cavities from the beam line and opening them, we found that many of cores showed a buckling at the inner radius. Also detachment of the epoxy coating intended to prevent rusting was observed. We report the detail of condition of MA cores and the relation between the impedance reduction and core condition.
KAERI, Daejon
In the RF linac, the RF system is roughly half of the total cost. The 13.56MHz rf generator is cheap and readily available. Therefore, an rf implanter which uses a cavity operating at the frequency of 13.56MHz has now been considered and developed at Proton Engineering Frontier Project (PEFP) - Korea. The implanter consists of a Duoplasmatron ion source, a triplet focusing magnet, an rf cavity, a bending magnet and an end chamber. It can accelerate particles up to 32keV/u for charge to mass ratio of 1/4. The implanter design concept, fabrication, testing and commissioning are presented in this presentation.
ITEP, Moscow
GSI, Darmstadt
Terra Watt Accumulator project (ITEP-TWAC) is aiming the accumulation of an ion beam accelerated up to 0.7 GeV/u in a storage ring providing intensity of heavy ions up to 10 power 12 particles per pulse for experiments on heavy ion beam-plasma interaction. For advanced experiments on high energy density physics the hollow cylindrical target is needed. A new method for RF rotation of the ion beam is applied for reliable formation of the hollow cylindrical beam. A principle of fast beam rotation by using a system of the multi-cell RF deflectors is considered in this paper. A four-cell H-mode deflecting cavity operating at the frequency of 298 MHz has been developed; similar 1.5 m long cavities being applied for both x- and y- directions. The shape of the deflecting electrodes has been optimized in order to provide the uniform deflection over the whole aperture taking into account both electric and magnetic components of the RF field. A deflecting system and a focusing quadrupole triplet applied to the beam with the energy of 450 MeV/u and normalized transverse emittance of 10*pi mrad*mm may form the quasi-hollow configuration with the inner radius up to 1.5 mm and thickness of 1 mm.
KEK, Ibaraki
For future high-intensity positron or proton accelerators, beam instability caused by electron cloud is one of the most important problems. Some coatings on inner surface of beam chambers with materials having low secondary emission yields such as titanium nitride (TiN), non-evaporable getter and so on have represented good effects against the electron cloud instability. In this study, diamond like carbon (DLC) and TiN coated chambers, and a copper chamber without coating were installed to an arc section of KEKB LER to make comparisons of total pressure, residual gas components and electron cloud activity during the beam operation under the same condition. Residual gas observation for the DLC coating revealed much higher hydrogen gas desorption because a process gas including hydrogen was used for the film growth. No remarkable hydrocarbon gas desorption was found. On the other hand, a mass peak of amu=14, that is N+ was prominent in the TiN coating. The electron cloud activity in the DLC coating was lower than the TiN coating and the copper chamber.
CELLS-ALBA Synchrotron, Cerdanyola del Vallès
The mechanical installation of the booster synchrotron of ALBA started in January 2009 and finished by having the system under vacuum in April 2009. The preparation of the booster vacuum system for the installation (partial assembly with the pumps and instrumentation, bakeout, etc) started already in September 2008. For the storage ring, the main mechanical installation was done from May to September 2009. The average pressure in the booster synchrotron is in the range of low 10-9 mbar and in the storage ring is in the low 10-10 mbar. The preparation of the installation, the installation and the present performance will be presented in this contribution. The first round of the booster commissioning took place at the end of 2009 and the beginning of 2010. The first data of the booster vacuum system commissioning are presented as well.
CERN, Geneva
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken
Pressure increases are observed with the first beams circulating in the CERN Large Hadron Collider (LHC) close to some collimators. This paper describes the vacuum performances of the collimators as measured in the laboratory and also the performances obtained in the machine. Based on these observations, estimations of some operational behavior such as pressure increase and NEG reactivation scenario are given.
GSI, Darmstadt
The present heavy ion synchrotron SIS-18 will be upgraded to be used as a booster for further synchrotrons being part of the FAIR project underway at GSI. We present a technique to measure the acceptance of an accelerator based on the extension of a previous method by the measurement of particle loss which we have applied to SIS-18. Here, we used an RF voltage to transversally excite a coasting heavy ion beam. The resulting transverse growth of the beam leads to particle loss when the beam width exceeds the limiting aperture. The acceptance has been determined from the time evolution of the beam current measured after particle have started to hit the aperture.
IAP, Frankfurt am Main
The beam transport experiments in toroidal magnets were first described in EPAC08 within the framework of a proposed low energy ion storage ring at Frankfurt University. The experiments with two room temperature 30 degree toroids are needed to design the accumulator ring with closed magnetic fields up to 6~8T. The test setup aims on building an injection system with two beam lines. The primary beam line for the experiments was installed and successfully commissioned in 2009. A special probe for ion beam detection was installed. This modular technique allows online diagnostics of the ion beam along the beam path. In this paper we present new results on beam transport experiments and discuss transport and transverse beam injection properties of that system.
INFN/LNF, Frascati (Roma)
CNAO Foundation, Milan
CERN, Geneva
University of Pavia, Pavia
The National Centre for Oncological Hadrontherapy (CNAO) is the first Italian centre for the treatment of patients affected by tumours with proton and carbon ions beams. Its status and commissioning results are presented in this conference in several papers. The synchrotron beam extraction is based on the use of a betatron core. The possibility of using the RF-knockout method as alternative system is being investigated, trying to optimise the performances with the already present hardware and minimum upgrades. A multiparticle tracking program has been written to simulate the beam dynamics during the extraction of the synchrotron, and to optimise the parameters of the radio frequency system. Two types of signals have been studied in order to obtain a constant spill with the minimum ripple: a carrier wave with a frequency and amplitude modulation, and a noise at a given range of frequencies modulated in amplitude. The results of the optimisation and the parameters of the proposed system are presented.
University of Fukui, Faculty of Engineering, Fukui
KEK, Ibaraki
KURRI, Osaka
In Kyoto University Research Reactor Institute (KURRI), the FFAG accelerator for accelerator driven sub-critical reactor (ADSR) system has been constructed and world's first ADSR experiments have started in March 2009. In order to upgrade beam intensity, multiturn charge exchange injection system for scaling FFAG accelerator is being studied. The 11MeV H- beam is injected from linac and is accelerated up to 100MeV in FFAG main ring. In this presentation, the detail of injection system is described and feasibility of such a low energy H- injection system is discussed.
KEK, Ibaraki
RIKEN Nishina Center, Wako
JAEA, Ibaraki-ken
The measurement of 12C(alpha,gamma) reaction is planned at TRIAC(Tokai Radioactive Ion Accelerator Complex). An intense pulsed alpha beam with the width of less 10ns and the interval between 250ns and 500ns is required for this experiment. Because the Split Coaxial RFQ (SCRFQ), which is one of the TRIAC accelerators, has a radio frequency of 26MHz, the bunch interval becomes 38.5ns. In order to make the bunch interval of 250ns or more, the pre-buncher with a frequency of 2-4MHz, is considered to be installed upstream of the SCRFQ. It is designed as the pre-buncher has two gaps with non-Pi mode. In order to make the bunching beam profile like a pseudo sawtooth-wave, the RF voltage synthesized three harmonic frequencies is applied to these gaps. Consequently, the pre-buncher has a compact size and no leakage electric field outside gaps, and can keep the RF voltage low. Recently, the beam test of this pre-buncher with a case of 2MHz-RF and SCRFQ was performed by using 16O4+ and 12C3+ beams. The clear bunch structure with a interval of 500ns was obtained by the SSD set downstream of the SCRFQ. The results of the beam test are almost consistent with those of the beam simulation code.
KEK, Ibaraki
RIKEN Nishina Center, Wako
JAEA, Ibaraki-ken
In TRIAC (Tokai Radioactive Ion Accelerator Complex), intense bunched beams are planned for measurements of 12C(alpha, gamma) reactions. For 2-4MHz bunching to the 26MHz linac beams, sawtooth-wave pre-buncher has been developed. Since the wave applied to the pre-buncher is pseudo sawtooth shape synthesized from three sine waves, particles in out-of-bunch phase become backgrounds to the bunched beams. In order to remove them, a multilayer chopper has been newly installed upstream the pre-buncher. The multilayer chopper has 20 electrodes (40mm wide, 10mm long, and 0.1mm thick) piled up with gaps of 1.9mm in vertically to the beam direction. And a square-shape electric potential (100V maximum, 2-4 MHz) is applied to each electrodes alternately. The short gap makes it possible to realize sharp beam-chopping with relatively low electric potential and weak leakage electric field, although beam particles could be lost by 5% or more, since this chopper is set on the way of beams. As a result, the ratio of bunched particles to backgrounds has been improved from 3:1 to 99:1 by the chopper. High intensity beam test by 16O4+ beam will be also reported.
KEK, Ibaraki
Thick carbon foils (>300ug/cm2) has been used for stripping of H- ion beam into protons at the injection stage of the 3GeV Rapid Cycling Synchrotron (3GeV-RCS) in J-PARC. The carbon stripping foils with high durability at high temperature >1800K are strongly required. We have recently developed a new irradiation system for lifetime measurement of the stripping foils using the KEK 650keV Cockcroft-Walton type of high voltage accelerator with high current pulsed negative hydrogen ion beam, which can simulate the high energy-depositions upon foils in the RCS. It is found that, by adjusting the peak intensity and the pulse length of the hydrogen ion beams appropriately, the energy deposition becomes equivalent to that exerted by the incoming hydrogen ions and the circulating protons at the injection process of the RCS. The most important factor that affects the foil lifetime is the foil temperature. During lifetime tests by this system, the temperature of foil is measured by a fast thermometer and by using a phototransistor in a pulsed mode (650keV, 10mA, 0.25msec, 25Hz). The new irradiation system and some preliminary results on lifetime of the carbon stripping foil will be presented.
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken
KEK, Ibaraki
J-PARC requires thick carbon stripper foils to strip electrons from the H- beam supplied by the linac before injection into the Rapid Cycling Synchrotron (RCS). Foil thickness is about 200 μg/cm2 corresponding to conversion efficiency of 99.7% from the primary H- beams of 181MeV energy to H+. For this purpose, we have successfully developed hybrid type thick boron-doped carbon (HBC) stripper foils, which showed a drastic improvement not only with respect to the lifetime, but also with respect to thickness reduction and shrinkage at high temperature during long beam irradiation. We started to study carbon stripper foils microscopically why carbon foils have considerable endurance for the beam impact by boron-doped. At first, we made a comparison between nominal carbon and HBC by the electric microscope and ion-induced analysis. In this paper, we will introduce some results for characteristics of HBC foils.
RIKEN Nishina Center, Wako
The RI beam factory at RIKEN Nishina Center needs high intensity of uranium ion beams. We constructed a new injector, RILAC2, which would provide several hundred times higher intensity. As a part of the RILAC2, we designed the low energy beam transport, LEBT, from the superconducting ECR ion source to the RFQ entrance. In this paper we present its requirements and problems, and show our design as the solutions to them. Especially we focus a technique of a pair of two solenoids to treat a rotational operation and a focusing operation independently. Based on this design, the LEBT was completed in March 2010. The RILAC2 will be operational this fall.
RIKEN Nishina Center, Wako
The RI beam factory at RIKEN Nishina Center needs high intensity of uranium ion beams. We have used so far the RFQ pre-injector upstream of the linac system, in which the extraction voltage of the ECR ion source is as low as 5.7 kV for the uranium beam. However, for much higher intensity beams from a newly developed superconducting ECR ion source, such a low voltage was expected to significantly increase their emittance due to the space charge effect. To reduce this effect, we prepared a new pre-injector line of 127 kV for uranium beams by placing the ion source on a high-voltage terminal. In this paper we present the design of the 127 kV medium energy beam transport, MEBT, and show the measured results through the line.
Imperial College of Science and Technology, Department of Physics, London
STFC/RAL, Chilton, Didcot, Oxon
JAI, Egham, Surrey
For the PAMELA medical non-scaling FFAG, carbon 6+ as well as proton particles are required. The general injection layout based on a cyclotron for proton and a Linac for carbon is considered. There are two options for pre-accelerating carbon ions for PAMELA, either accelerating carbon with the charge state 4+ from the ion source and stripping after the pre-accelerator or directly accelerating carbon 6+ ions all the way from the ion source. For both options solution has been investigated. Simulations of beam dynamics for both particle species are presented. The resulting schemes based on either the single turn or multiturn injection into the first FFAG ring are discussed.
GSI, Darmstadt
NSCL, East Lansing, Michigan
Electron Cyclotron Resonance Ion Sources (ECRIS) are increasingly used as ion source for different types of accelerator because of their high current densities for highly charged ions. To investigate the ion beam quality, normally delivered to the RFQ of the high charge state injector at GSI, we had the chance to install a viewing target close to the position of ion beam injection into the RFQ. The profile visible on the viewing target could be recorded through a regular glass window by a simple camera outside the vacuum. The RFQ itself has been removed for these measurements. We have found a highly structured ion beam distribution at that position. These structures, already caused by the hexapolar field within the ion source have already been observed directly behind the extraction. They are transported through the beam line without becoming homogeneous, which indicates a high degree of space charge compensation for that cw-beam. If the full beam line is mastered by the dipole, all charge states show similar ion beam distribution on the target for a given extraction voltage. This is also a hint, that the structures have been produced within the source already.
ISIR, Osaka
Femtosecond electron beam pulse radiolysis which has time resolution of 250 fs was achieved by a Photocathode RF gun LINAC in the ISIR, Osaka University. And geminate ion recombination (charged pair dynamics) in n-dodecane was studied. Kinetics of the Radical cation of n-dodecane was measured. As a result, the existence of the excited-radical cation, and generation of the radical cation via relaxation from the excited-radical cation were suggested. Those new results were obtained in the field of the radiation chemistry by the photocathode RF gun.
TU Darmstadt, Darmstadt
KVI, Groningen
The REX-ISOLDE facility at CERN delivers a great variety of radioactive ion beams with energies up to 3.0 MeV/u and therefore allows nuclear structure physics experiments far from stability. A crucial point for the experimentalist is the knowledge of possible unwanted beam contaminations, either from the bunching and charge-breeding procedure (residual gas ions) or directly from the ion-production process (isobaric contaminants). The sources of these contaminations will be discussed, as well as possible ways of elimination during the post-acceleration. Methods to analyse the beam composition in the relevant energy range will be presented with an emphasis on the experimental challenges in Gamma-spectroscopy experiments and data analysis.
INFN-Bari, Bari
BINP SB RAS, Novosibirsk
The charge breeding technique is used for Radioactive Ion Beam (RIB) production in the Isotope Separation On Line (ISOL) method in order of optimizing the re-acceleration of the radioactive element ions produced by a primary beam in a thick target. That technique is realized by using a device capable of increase the radioactive ion charge state from +1 to a desired value +n. In some experiments a continuous RIB of a certain energy could be required. The EBIS based charge breeding device cannot reach a real CW operation because the high charge state ions produced are extracted by the same part where the 1+ ions are injected, that is, from the electron collector. In this way, the ions extraction system, placed in the electron beam collector, can be left only to extract the n+ ions, and then the CW operation, at least in principle, could be reached. In this paper, a charge breeding test experiment based on a EBIS which has an e-gun with hollow cathode will be described. Furthermore, the status report of the experiment that is under way at the INFN Laboratori Nazionali di Legnaro (LNL) will be presented.
INFN/LNL, Legnaro (PD)
In singly charged positive ion sources, the study of beam extraction is greatly simplified by the existence of a well defined place for plasma to beam transition, given by the well known Bohm criterion, where the ion flow speed equals the speed of sonic perturbation, known as Bohm speed. Most of the ion extraction simulation codes are implicity based on the concept of quasi neutrality in the plasma region, as limited by the Bohm criterion. In negative ion source the existence of an electron coextracted beam and of a magnetic filter makes the relevant speed less clear. Moreover there are several scale lengths to be considered: the Debye length, that is typically 0.01 mm, the electron and ion gyroradius, the H- scattering, absorbtion and production length. In the development of negative ion source for NBI injector for ITER, the production of H- at wall and the negative sheath so generated is also important. A critical evaluation of these regimes is obtained with 1D (one space dimension) models, mostly restricted to magnetic filter parallel to the extraction wall. Some remarks on 2D simulation codes is also given.
INFN/LNL, Legnaro (PD)
Consorzio RFX, Associazione Euratom-ENEA sulla Fusione, Padova
The development of neutral beam injectors (NBI) for tokamak like the ITER project and beyond requires high performance and huge negative ion sources (40 A of D- beam required); it was recently accepted that inductive plasma coupled (ICP) radiofrequency sources are the preferred option. It is therefore useful to have a moderate size source of modular design to test and verify both construction technologies and components and simulation codes; here the NIO1 design (60 kV, 9 beamlets of 15 mA H- each) and construction status are described. Source is assembled from disk shaped modules, for rapid replacement; the beamlets are arranged in 3 times 3 square matrix so that 90 degree rotation of modules is possible and allows to cross or to align the magnetic filters used in the source. The 2 MHz rf coil and the rf window are a simply replaceable module. Extensive rf absorption and magnetic coil simulations were performed. Related beam simulation and fast emittance scanner development are described elsewhere.
Department of Energy Sciences, Tokyo Institute of Technology, Yokohama
BNL, Upton, Long Island, New York
RIKEN Nishina Center, Wako
In a laser ion source, a high power pulsed laser shot focused on a solid state target produces laser ablation plasma. This plasma has initial velocity towards the normal direction of the target and simultaneously expands three dimensionally. Since charge state distribution, velocity distribution and plasma temperature strongly depends on laser power density, power density is one of the important parameter to the angular distribution of plasma. Angular distribution of expanding plasma was measured by changing laser power density. Details of the experiment will be shown in the paper.
RCNP, Osaka
The upgrade program of the AVF cyclotron is in progress since 2004 at Research Center for Nuclear Physics (RCNP), Osaka Univ., for improving the quality, stability and intensity of accelerated beams. An 18 GHz superconducting ECRIS has been installed to increase beam currents and to extend the variety of ions, especially for highly charged heavy ions which can be accelerated by RCNP cyclotrons. The production development of several ion like B, C ~ Xe by gas mixing or MIVOC has been performed. In order to extend the variety of ions more, metal viper or spatter system has also been installed to 10GHz NEOMAFIOS with minimum modifications. The details of these recent developments will be presented.
RLNR, Tokyo
High intensity heavy ion beam acceleration in the low energy region is one of the most difficult conditions to achieve, because the space charge effect is extremely strong. In order to generate a high intensity beam using linacs, we have to avoid beam loss by the space charge effect as much as possible. Multibeam acceleration has been proposed as a possible method of reducing the space charge effect. If one cavity could be used to accelerate several beams, a significant gain would be made in installation space and operational cost saving. In this study we look at a multibeam type radio frequency quadrupole (RFQ) linac in order to accelerate several beams using a single cavity. The RFQ electrodes are placed in an IH type cavity; This structure is known as a IH-RFQ linac. GSI in Germany proposed a multibeam type IH-RFQ linac with several beam channels in a single cavity. However, this multibeam type IH-RFQ linac has yet to be manufactured. We manufactured a 2-beam type IH-RFQ linac as a prototype of the multibeam type IH-RFQ. The linac outputs C2+ beam of 60 keV/u and 44 mA/channel in the design value. We will report about the beam acceleration test of the linac.
RIKEN Nishina Center, Wako
SHI Accelerator Service Ltd., Tokyo
The next generation heavy ion accelerator facility, such as the RIKEN RIBF, requires great variety of high charged heavy ions with a magnitude higher beam intensity than currently achievable. In the last decade, performance of the ECR ion sources has been dramatically improved with increasing the magnetic field and RF frequency to enhance the density and confinement time of plasma. Furthermore, the effects of the key components (magnetic field configuration, gas pressure etc) on the ECR plasma have been revealed. Such basic studies give us how to optimize the ion source structure. Based on these studies and the technology, we successfully constructed the new 28GHz SC-ECRIS which has a flexible magnetic field configuration to enlarge the ECR zone and to optimize the field gradient at ECR point. In the test experiment, we obtained the direct evidence that the field gradient and the zone size strongly affect the beam intensity. It concludes that the gentler field gradient and large ECR zone size gives intense beam of highly charged heavy ions from ECR plasma. In this contribution, we report the systematic study of these effects on the beam intensity of highly charged heavy ions.
RIKEN Nishina Center, Wako
The superconducting ECR ion source enabled to use a 28 GHz microwave source had been developed to provide intense beam of highly charged heavy ions like U35+ to the RIKEN RI-beam factory (RIBF) since 2007. The first plasma was lit in May of 2009 and it was succeeded in providing the uranium beam to the RIBF in December. In this operation, uranium ions were supplied with sputter method and two 18 GHz microwave sources were used. The beam intensity of the uranium ion exceeded 14μAmps, which was more than five times larger than that for 18 GHz ECR ion source of a usual type. The extraction system consists of the accel-decel electrode system, a solenoid coil and a 90 degreeanalyzing magnet. We measured the profiles and emittances of the extracted beams for several ion species and compared with the calculated results with 'OPERA-3d' including space charge effect. And we shall discuss the beam dynamics at the extraction region such as the relationship between the beam emittance and the operating parameters.
Department of Energy Sciences, Tokyo Institute of Technology, Yokohama
BNL, Upton, Long Island, New York
Kyushu University, Department of Applied Quantum Physics and Nuclear Engineering, Fukuoka
The Electron Beam Ion Source (EBIS) project at Brookhaven National Laboratory is a new heavy ion pre-injector for Relativistic Heavy Ion Collider (RHIC) and NASA Space Radiation Laboratory science programs. An important requirement for EBIS is an ion source capable of efficiently providing a variety of heavy ion species to many users within short period of time. In that respect, Laser Ion Source (LIS), which can supply many heavy ion species from solid targets, is a good candidate for RHIC-EBIS, however, LIS has an issue to be resolved. This is the requirement of limited current in low energy beam transport. LIS in the condition that laser power density is low, is expected to provide limited current with long pulse length. The discussions of the experimental results are presented.
KAPRA, Cheorwon
SNU, Seoul
University of Ulsan, Ulsan
The physics design of a Photo Fission Ion Source (PFIS) which will be used in a heavy ion accelerator is introduced. The design variables being considered are asymmetric magnetic field, cooling, neutron reflector and modulator (high density graphite), UCx target, bremsstrahlung power, microwave power and fission fragments (ions). Based on the design studied performed by using Monte Carlo codes and nuclear data, we will present the results, performance, optimization, ion distribution, bremsstrahlung power dependent radiation distribution, and temperature distributions. Finally we will conclude the feasibility of PFIS.
JINR, Dubna, Moscow Region
The radioactive ion isotopes 11C6+, 10C6+ and others are produced at interaction of primary carbon ion beam with target. These isotopes can be applied for Positron Emission Tomography. The projectile-fragmentation method is used for the production of radioactive isotopes. The intensity of radioactive ion beam is defined by the target optimal thickness, material and by available longitudinal and transverse acceptances of transportation channel. An increase of target thickness permits to improve production rate of radioactive ion beams, however it increase the energy and angle spreads of secondary ions and finally it gives a reduction of number of useful radioactive ions which can be transported to the PET camera. The GEANT 4 simulations related to formation of 11C6+ secondary ion beams at interaction with different targets are discussed.
JINR, Dubna, Moscow Region
NIRS, Chiba-shi
The 11C isotopes are produced in the nitrogen gas target irradiated by a proton beam. If the nitrogen target contains 5% of hydrogen, about 5·E12 methane molecules can be produced each 20 minutes. The separated methane is loaded into the ion source. The technique used for formation of radioactive carbon beams was developed and tested in the JINR electron string ion source (ESIS) Krion-2. The measured conversion efficiency of methane molecules to carbon ions is rather high; it corresponds to 17 % for C4+ ions. The experimentally obtained C4+ ion intensity in ESIS was about 2·E9 ppp. The new ESIS-5T is under construction in JINR now at project ion intensity of 6·E9 ppp. Accelerated 12C ion beams are effectively used for cancer treatment at HIMAC. The positron emission tomography is the most effective way of tumor diagnostics. The intensive radioactive 11C ion beam could allow both these advantages to be combined. It could be used both for cancer treatment and for on-line PET. Formation of a primary radioactive ion beam at an intensity on the tumor target of 1·E8 pps allows the cancer treatment by the scanning radiation method and on-line dose verification.
JINR, Dubna, Moscow Region
VNIIEF, Sarov (Nizhnii Gorod)
JINR/LHE, Moscow
The Electron String Ion Source (ESIS) developed at JINR is effectively used here during the last decade. The Tubular Electron String Ion Source (TESIS) has been put forward recently to obtain a 1-2 orders of magnitude increase in the ion output as compared with ESIS. The project is aimed at creating TESIS and studying the electron string in the tubular geometry. The new tubular source with a superconducting solenoid up to 5 T is under construction now. The method of the off axis TESIS ion extraction will be realized to get TESIS beam emittance comparable with ESIS emittance. It is expected that this new TESIS will meet all rigid conceptual and technological requirements and should provide an ion output approaching 10 mA of Ar16+ ions in the pulsed mode and about 10 μA of Ar16+ ions in the average current mode. Design, construction and test of separate TESIS systems are discussed in this report.
ESS Bilbao, Bilbao
Fundación TEKNIKER, Eibar (Gipuzkoa)
Bilbao, Faculty of Science and Technology, Bilbao
University of the Basque Country, Faculty of Science and Technology, Bilbao
STFC/RAL/ISIS, Chilton, Didcot, Oxon
ESS-Bilbao, Zamudio
Imperial College of Science and Technology, Department of Physics, London
Elytt Energy, Madrid
The rationale behind the Bilbao Accelerator Ion Source Test Stand (ITUR) project is to perform a comparison between different kinds of hydrogen ion sources using the same beam diagnostics setup. In particular, a direct comparison will be made in terms of the emittance characteristics of Penning-type sources such as those currently being used in ISIS (UK) and those of microwave type such as CEA-Saclay and INFN. The aim here pursued is to build an Ion Source Test Stand where virtually any type of source can be tested and, thus, compared to the results of other sources under the same gauge. It would then be possible to establish a common ground for effectively comparing different ion sources. The work here presented reports on the first simulations for the H-/H+ extraction system, as well the devices that conform the diagnostic vessel: Faraday Cup, Pepperpot and Retarding Potential Analyzer (RPA), among others.
STFC/RAL/ISIS, Chilton, Didcot, Oxon
The Front End Test Stand (FETS) under construction at the Rutherford Appleton Laboratory is the UK's contribution to research into the next generation of High Power Proton Accelerators (HPPAs). Running at duty cycles of up 50 Hz with pulse lengths of 2 ms are required. This paper presents initial Hminus beam currents and emittance measurements for long pulse lengths.
Muons, Inc, Batavia
JLAB, Newport News, Virginia
The operation of the RHIC facility at BNL and the Electron Ion Colliders (EIC) under development at Jefferson Laboratory and BNL need high brightness ion beams with the highest polarization. Charge exchange injection into a storage ring or synchrotron and Siberian snakes have the potential to handle the needed polarized beam currents, but first the ion sources must create beams with the highest possible polarization to maximize collider productivity, which is proportional to a high power of the polarization. We are developing one universal H-/D- ion source design which will synthesize the most advanced developments in the field of polarized ion sources to provide high current, high brightness, ion beams with greater than 90% polarization, good lifetime, high reliability, and good power efficiency. The new source will be an advanced version of an atomic beam polarized ion source (ABPIS) with resonant charge exchange ionization by negative ions. An integrated ABPIS design will be prepared based on new materials and an optimized magnetic focusing system. Polarized atomic and ion beam formation, extraction, and transport for the new source will be computer simulated.
Muons, Inc, Batavia
ORNL, Oak Ridge, Tennessee
Development of novel modifications of H- source designs is proposed. The new source will be an advanced version of a Penning DT SPS (Dudnikov-Type Penning Surface Plasma Source) which will generate brighter beam in noiseless discharge, deliver up to 20 mA average current with better electrode cooling using new materials, and have longer lifetime, fast beam chopping capability, and reduced cesium loss.
Muons, Inc, Batavia
UMD, College Park, Maryland
ORNL, Oak Ridge, Tennessee
In this project we are developing an RF H- surface plasma source which will synthesize the most important developments in the field of negative ion sources to provide high pulsed and average current, high brightness, good lifetime, high reliability, and higher power efficiency. We describe two planned modifications to the present SNS external antenna source in order to increase the plasma density near the output aperture: 1) replacing the present 2 MHz plasma-forming solenoid antenna with a 13 MHz saddle-type antenna and 2) replacing the permanent multicusp magnetic system with a weaker electro-magnet. Progress of this development will be presented.
Muons, Inc, Batavia
LBNL, Berkeley, California
Induction linear accelerators are featured in accelerator-based research currently supported by the Office of Fusion Energy Sciences. Over the next few years, the research will concentrate on developing intense ion sources and on studying the physics of spatial compression, neutralized transport, and focusing of the beam. The large diameter of lithium alumino-silicate ion emitters for large currents represents the current state of the art for emission densities of 1-1.5 mA/cm2. Also, operating temperatures of the surface are limited by the temperature of alumina-potted heater packages. We propose a novel system for increasing the emission of lithium ions from β-eucryptite through modification of the surface morphology by sputter etching with argon plus other gases. The resulting local field enhancement will increase the ion emission over that of a microscopically flat surface. In addition, a free-standing graphite heater assembly will be used to increase the temperature of the surface of the emission source.
BNL, Upton, Long Island, New York
Kyushu University, Department of Applied Quantum Physics and Nuclear Engineering, Fukuoka
Department of Energy Sciences, Tokyo Institute of Technology, Yokohama
The Laser Ion Source is an efficient method for generating heavy ions for acceleration. The output produces high current and high charge-state beams from almost any type of elemental species. Using the Laser Ion Source apparatus, we consider improving the efficiency of this method by heating the target prior to laser irradiation. Prior deposition of any thermal energy into the target could add with the energy being delivered by the pulsed laser to produce higher current beams. These beams could be composed of higher charge-state ions and/or an increased net number of ions. We investigate by using a retrofitted heater to heat the target to a variety of high temperatures and subsequently analyze the produced beam.
Kyushu University, Department of Applied Quantum Physics and Nuclear Engineering, Fukuoka
BNL, Upton, Long Island, New York
Department of Energy Sciences, Tokyo Institute of Technology, Yokohama
A laser ion source can provide high-current highly-charged ions with a simple structure. Previously we have demonstrated acceleration of >60 mA carbon and aluminum ion beams using a direct plasma injection scheme. However, it was not easy to control the ion pulse width. Especially to provide longer ion pulse, a plasma drift length which is the distance between laser target and extraction point, has to be extended and the plasma is diluted severely. We apply a solenoid field to prevent reduction of ion density at the extraction point. A solenoid field of a few hundred Gauss enhanced the ion density up to 40 times. We present these results, including details of the solenoidal field effects on the expanding laser plasma.
TU Darmstadt, Darmstadt
GSI, Darmstadt
The central accelerator SIS100 of the FAIR-facility will provide high intensity, intermediate charge state heavy ion beams. In order to assure a reliable operation with the intermediate charge states, a special synchrotron design, including ion catcher system had to be developed. Intermediate charge state heavy ions suffer from high cross sections for ionization. Due to the dedicated synchrotron layout, ions which have been further stripped by collisions with residual gas atoms are not lost uncontrolled onto the beam pipe but are caught by the ion catcher system in the cryogenic arcs. The construction and test of a cryo-catcher prototype at GSI is a workpackage of the EU-FP7 project COLMAT. A prototype catcher including cryostat will be set-up at GSI to perform measurements with heavy ion beams of the heavy ion synchrotron SIS18.
GSI, Darmstadt
TU Darmstadt, Darmstadt
INFIM, Bucharest
Within the frame of the EuCARD program, the GSI Darmstadt is performing accelerator R&D in workpackage 8: ColMat. The effort is focused on materials important for building the FAIR accelerator facility at GSI and the LHC upgrade at CERN. Accelerator components and especially protection devices have to be operated in high dose environments. The radiation hazard occurs either by the primary proton and ion beams or the secondary radiation. Detailed numerical simulations have been carried out to study the damage caused to solid targets by the full impact of the LHC beam as well as the SPS beam. Tungsten, copper and graphite targets have been studied. Experimental an theoretical studies on radiation damage on materials used for the LHC upgrade and the FAIR accelerators are performed at the present GSI experimental facilities. Technical decisions based on these results will have an impact on the FAIR component specifications. A cryogenic ion-catcher prototype will be constructed and tested. The ion-catcher is essential for reaching highest heavy ion beam intensities in SIS100. The prototype will be set-up at GSI to perform measurements with heavy ion beams of synchrotron SIS18.
UBC & TRIUMF, Vancouver, British Columbia
TRIUMF, Vancouver
This paper describes tracking studies of non-scaling (NS) FFAGs using cyclotron codes in place of the more conventional lumped-element synchrotron codes. The equilibrium orbit code CYCLOPS determines orbits, tunes and period at fixed energies, while the general orbit code GOBLIN tracks a representative bunch of particles through the acceleration process. Results will be presented for the EMMA linear NS-FFAG under construction at Daresbury (10-20 MeV electrons), and for two non-linear NS-FFAG designs: Rees's isochronous IFFAG (8-20 GeV muons) and Johnstone's design for ADSR (250-1000 MeV protons). Our results are compared with those obtained using lumped-element codes. In the case of EMMA, results are presented for both the measured and design fields.
USTC/NSRL, Hefei, Anhui
Fixed-Field Alternating Gradient (FFAG) accelerator accelerates in smaller costs heavy-ion with higher beam current than conventional circular accelerator, which could be more useful for the study of radioactive material. In this paper, the periodic focusing structure model of a Helium ion FFAG with a few MeV energy, which is contributed to study the impact of Helium embitterment on fusion reactor envelope material is proposed. A large-aperture magnet for Helium ion FFAG synchrotron is designed by using a 3D magnetic field simulation code OPERA-3D. The linear and nonlinear beam dynamics is studied through tracking the particle in the magnetic field generated by OPERA-3D.
HHUD, Dusseldorf
National University of Defense Technology, Changsha, Hunan
By using multi-dimensional particle-in-cell simulations, we investigate the stability of proton beam acceleration in a two-specie ultra-thin foil. In this two-specie regime, the lighter protons are initially separated from the heavier carbon ions due to their higher charge-to-mass ratio Z/m. The laser pulse is well-defined so that it doesn't penetrate the carbon ion layer. The Rayleigh-Taylor-like (RT) instability seeded at the very early stage then only degrades the acceleration of the carbon ions which act as a "cushion" for the lighter protons. Due to the absence of proton-RT instability, the produced high quality mono-energetic proton beams can be well collimated even after the laser-foil interaction concludes.
JAEA, Kyoto
APRI-GIST, Gwangju
ILE Osaka, Suita
Central Research Institute of Electric Power Industry, Yokosuka-shi, Kanagawa
High-intensity laser and thin-foil interactions produce high-energy particles, hard x-ray, high-order harmonics, and terahertz radiation. A proton beam driven by a high-intensity laser has received attention as a compact ion source for medical applications. We have performed the high intensity laser-matter interaction experiments using a thin-foil target irradiated by Ti:sapphire laser (J-KAREN) at JAEA. In this laser system, the pulse duration is 40 fs (FWHM). The laser beam is focused by an off-axis parabolic mirror at the target. The estimated peak intensity is ~5x1019 W/cm2. We have developed on-line real time monitors such as a time-of-flight proton spectrometer which is placed behind the target and interferometer for electron density profile measurement of preformed plasma. We observed the maximum proton energy of ~7 MeV.
UCLA, Los Angeles
Manhattanville College, Purchase, New York
The Micro-Accelerator Platform is an optical-wavelength microstructure for laser acceleration of particles, currently under development at UCLA. It is a slab-symmetric structure and can be constructed in layers using existing nanofabrication techniques. We present several possible fabrication techniques and preliminary experimental outcomes for manufacturing this structure.
BNL, Upton, Long Island, New York
Imperial College of Science and Technology, Department of Physics, London
UMD, College Park, Maryland
Stony Brook University, StonyBrook
Recent theoretical and experimental studies point to better efficiency of laser-driven ion acceleration when approaching the critical plasma density regime. Simultaneously, this is the condition for observing solitons: "bubble"-like quasi-stationary plasma formations with laser radiation trapped inside. Exploring this regime with ultra-intense solid state lasers is problematic due to the lack of plasma sources and imaging methods at ~1021/cc electron density. The terawatt picosecond CO2 laser operated at Brookhaven's Accelerator Test Facility offers a solution to this problem. At 10 μm laser wavelength, the CO2 laser shifts the critical plasma density to 1019/cc which is attainable with gas jets and can be optically probed with visible light. Capitalizing on this approach, we focused a circular-polarized CO2 laser beam with a0=0.5 onto a hydrogen gas jet and observed monoenergetic proton beams in the 1 MeV range. Simultaneously, the laser/plasma interaction region has been optically probed with a 2nd harmonic picosecond Nd:YAG laser to reveal stationary soliton-like plasma formations. 2D PIC simulations agree with experimental results and aid in their interpretation.
CEA, Gif-sur-Yvette
A main interest in the high intensity ion linacs is the control of the particle loss in the vacuum chamber. A extremely low fraction of the beam (10-4 or 10-7) is sufficient to complicate the hands on maintenance in such accelerator. Beam mismatching being a major source of halo, it is proposed a non invasive technique to adapt the beam to a periodic focusing channel of a linac based on a FDO of FODO lattice. It is demonstrated that only the matched beam can correspond to a particular signature of the quadrupolar moment of the Beam Positions Monitors. This technique allows also to measure the emittance value or evolution along the channel.
JINR, Dubna, Moscow Region
The main losses of the injected beam are localized at the centre region of the cyclotron. One of the problems is the defocusing action of the spiral inflector. At the present work the method of decreasing of the vertical defocusing effect of the spiral inflector is presented. The decreasing of the vertical defocusing is achieved by means of special form of the inflector electric field. At FLNR, JINR, the new type of the inflector was investigated and manufactured. At the present time the inflector is installed and works at the U400 cyclotron. The experiments with the new inflector have shown the increasing of the beam intensity and more tuneble work of the cyclotron.
PPPL, Princeton, New Jersey
This paper presents results of advanced numerical simulations demonstrating the feasibility of tight collective focusing of intense ion beams for the Neutralizing Drift Compression Experiment (NDCX-I). In the collective focusing scheme, a weak magnetic lens provides strong focusing of an intense ion beam carrying an equal amount of neutralizing electron background [S. Roberston, Phys. Rev. Lett. 48, 149 (1982)]. For instance, a solenoidal magnetic field of several hundred gauss can focus an intense neutralized ion beam within a short distance of several centimeters. The enhanced focusing is provided by a strong self-electric field, which is produced by the collective electron dynamics. The numerical simulations are performed with the LSP particle-in-cell (PIC) code, and the results of the simulations are found to be in good agreement with analytical predictions. Collective focusing limitations due to possible heating of the co-moving electrons during the transverse compression are also discussed.
MEPhI, Moscow
At present a number of high energy heavy ion linear accelerator projects are discussed. FRIB accelerator is under R&D in Michigan University in USA, GANIL in France etc. The RIA (AEBF) project was designed in ANL, USA some years ago*. The linac should consist of a number of ion sources, matching system, pre-buncher and high energy sections. Using of independently phased short SC resonators with drift tubes is possible for beam acceleration and SC solenoids or quadruple can be used for focusing. The alternative phase focusing can be also useful**. The beam envelope control is one of the main problems in this linac. The method of analytically beam dynamics investigation will be discussed in the future report. The conditions of beam envelope control will be carried out by using of especially averaging method, discussed in*** initially.
* P.N.Ostroumov et al., Proc. of PAC01, p.4080
** E.S.Masunov, A.V.Samoshin, Proc. of PAC07, p.1568
*** V.S.Dyubkov, E.S.Masunov, Probl. of Atom. Sci.&Tech., Ser. Nucl. Phys. Investig. (in press)
National Taras Shevchenko University of Kyiv, Radiophysical Faculty, Kiev
The new type of oriental motion, so called parametric channeling of accelerated charged particles with internal energy structure in crystals or transversal focusing fields (TFF) is studied [*,**]. Peculiarities of this motion are connected with parametric coupling of transversal oscillations of fast particle in TFF (e.g. averaged field of crystal plains) and oscillations caused by internal processes in particle. Parametric channeling is investigated for small charged mesomolecules, atomic ions and nuclei with internal resonances, relativistic electrons. It was shown that such parametric coupling leads to the possibility of beam cooling and "collapse": critical decrease of transversal oscillations of moving structured ion in TFF due to energy transfer from this ion to its own internal electron (for atomic ion) or its internal low energy nuclear state (for fast nuclei). Also it was shown that parametric beam cooling with the decrease of transversal energy can take place at axial relativistic electron beams channeling. This process is caused by the parametric coupling between quantized channeling states and electron spin states in effective magnetic field in moving system.
* M.V.Vysotskyy V.I.Vysotskii, N.V.Maksuyta. Journal of Surface Investigation, V.2, No 2 (2008) 245.
** V.I.Vysotskii, M.V.Vysotskyy. Journal of Surface Investigation, 2008, V.2, No 2 (2008), 253.
CERN, Geneva
The CLOUD Project, where a high-energy physics accelerator is being used to study atmospheric and climate science for the first time, will be described.