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.
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
NIRS, Chiba-shi
Construction of new treatment facility as an extension of the existing HIMAC facility, in which all treatment room will be equipped with a 3D pencil beam scanning system, is in progress at NIRS. The challenge of this project is to realize treatment of a moving target by scanning irradiation, because pencil beam scanning is more sensitive to organ motions compared with the conventional broad-beam irradiation. To accomplish practical moving target irradiation, a prototype of the scanning irradiation system was constructed and installed into existing HIMAC physics experiment course. One of the most important features of the system to be tested is fast scanning toward moving target irradiation with a relatively large number of rescannings within an acceptable irradiation time. Commissioning of the prototype is successfully in progress cooperating with highly stabilized beam provided by the HIMAC accelerator complex. We will report the design of the system and the status of the beam study.
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).
TUB, Beijing
Tsinghua University, Beijing
The method of intensity-modulated radiotherapy (IMRT) is increasingly concerned by the medical world in recent years. Based on the performance characteristic of IMRT accelerator, a 6MeV S-band on axis-coupled SW, Suitable for IMRT, electron linear accelerating tube has been developed in Accelerator Lab of Tsinghua University. This paper provides the design performance characteristics of the tube and the results of the high-power tests,analyzes the performance and problems in the operation.
KAERI, Daejon
Proton therapy has features of minimal effect on tumor surrounding healthy tissue and huge damage on tumor volumes specifically. Due to these characteristics of proton therapy the number of patients with receiving proton therapy is increasing every year. Proton therapy is useful for tumor treatment but still not know mechanism of proton beam that how to kill the tumor cells. In korea, a lot of current research progressed at the cellular level by using a proton accelerator, the animal experiments was not held virtually because of the absence of the device. In this study, we installed a animal experiment device for proton beam irradiation in MC-50 cyclotron LEPT (Low Energy Proton Therapy) beam line. Bouls and collimator, we easily made to be installed and we used PMMA sheet in order to reduce the energy. In addition, we used ridge filter type modulator for making SOBP and depth-dose measurement system for a proton beam dosimetry.
SLAC, Menlo Park, California
Shortages of 99Mo, the most commonly used diagnostic medical isotope, have caused great concern and have prompted numerous suggestions for alternate production methods. A wide variety of accelerator-based approaches have been suggested. In this paper we survey and compare the various accelerator-based approaches.
The University of Tokyo, Nuclear Professional School, Ibaraki-ken
JAEA, Ibaraki-ken
UTNL, Ibaraki
Dual energy X-ray system using high energy X-ray from linear accelerator (Linac) applies two times X-ray irradiation which have different energy spectrum each other in many cases. Two different X-rays yield two tomography images which is analyzed through numerical calculation with pixel values for material recognition of a object. However if the X-ray generation is not stable, the results of numerical calculation shows irregular tendency during the inspection. We propose the scintillator array in detection part, because two tomography images are obtained by just one irradiation. That leads to the time saving during inspection and the cost down for additional facilities. The optimal condition is researched to increase the ability of material recognition in interesting materials designing the detector with CsI and CdWO4 scintillators. We focus on the discrimination between heavy materials and light materials with the system in the research. X-ray source is 950 keV X-band Linac we developed for industrial application, which produce pulsed X-ray, 10 pps with around 400 mA beam current.
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.
KAERI, Daejon
During the beam irradiation experiments with more than a few MeV energetic protons, nuclear reactions are occurred in sample materials. Because of these nuclear reactions, the samples are activated so many kinds of additional problems for the post-processing of the samples are caused; such as time-loss, inconvenience of sample handling, personal radiation safety, etc. For in-vitro experiments, we observe death of tumor cells by proton irradiation. The use of large activated container material can cause erroneous results in this case. To solve these problems, we studied why the samples are activated and how the level of the activation can be reduced. In our proton beam irradiation experiments, the target materials can be defined as the container and sample itself. We could easily reduce activation of container material comparing to activation of sample itself. Therefore, we tried to find less activated container material by irradiating proton beam in PS (Polystyrene), PMP (Polymethypenten), and PMMA (Poly methacrylate). We used 45 MeV proton beams (MC-50 Cyclotron, KIRAM) with 10 nA.
Manchester University, Manchester
UMAN, Manchester
University of Huddersfield, Huddersfield
Thorium fueled Accelerator Driven Subcritical Reactors have been proposed as a more comprehensive alternative to conventional nuclear reactors for both energy production and for burning radioactive waste. Several new classes have been added by the authors to the GEANT4 simulation code, extension which allows the state-of-the-art code to be used for the first time for nuclear reactor criticality calculations. In this paper we investigate the impact of the subcriticality and injected proton beam energy on the ADSR performance for novel ADSR configurations involving multiple accelerator drivers and associated neutron spallation targets within the reactor core.
Muons, Inc, Batavia
Fermilab, Batavia
We study electron-positron in-flight annihilation as a potential source of quasi-monoenergetic photon (or gamma-ray) beams. A high-intensity tunable-energy (1.5 MeV to 15 MeV) gamma source has many potential uses in medical, industrial and security applications. Several electron-positron collision geometries are considered: a) head-on; b) collinear; and c) positron beam incident on a fixed electron target. We analyze advantages of each of the geometries in order to optimize parameters of the generated gamma-ray beams.
Muons, Inc, Batavia
Positrons produced by electrons impinging on a target cover a broad momentum range. By bending the positrons 180° in a dipole magnetic field the momenta are dispersed according to their momenta along the exit plane of the magnet. A wedge-shaped absorber placed at the exit plane can reduce the momenta accordingly to produce a quasi-monochromatic beam of positrons. Simulation results are presented for 2 to 10 MeV/c quasi-mono-chromatic positrons produced by 75 MeV electrons on a tungsten target.
Muons, Inc, Batavia
Fermilab, Batavia
A compact tunable gamma ray source has many potential uses in medical and industrial applications. One novel scheme to produce an intense beam of gammas relies on the ability to create a high flux of positrons. We present various positron production methods that are compatible with this approach for producing the intense beam of gammas.
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.
Università di Brescia, Brescia
I.N.F.N., Pavia
CERN, Geneva
The AEGIS experiment is expected to be installed at the CERN Antiproton Decelerator in a very close future, since the main goal of the AEGIS experiment is the measurement of gravity impact on antihydrogen, which will be produced on the purpose. Antihydrogen production implies very challenging environmental conditions: at the heart of the AEGIS facility 50 mK temperature, 10-12 mbar pressure and a 1 T magnetic field are required. Interfacing extreme cryogenics with ultra high vacuum will affect very strongly the design of the whole facility, requiring a very careful mechanical design. This paper presents an overview of the actual design of the AEGIS experimental facility, paying special care to mechanical aspects. Each subsystem of the facility - ranging from the positron source to the recombination region and the measurement region - will be shortly described. The ultra cold region, which is the most critical with respect to the antihydrogen formation, will be dealt in detail. The assembly procedures will be considered too, as they are expected to be critical to make the set-up phase easier, as well as to make possible any future improvement of the facility itself.
KEK, Ibaraki
JAI, Egham, Surrey
OXFORDphysics, Oxford, Oxon
Optical Transition Radiation (OTR) appearing when a charged particle crosses a boundary between two media with different dielectric properties has widely been used as a tool for transverse profile measurements of charged particle beams in various facilities worldwide. The resolution of the conventional monitors is defined by so-called Point Spread Function (PSF) dimension - the source distribution generated by a single electron and projected by an optical system onto a screen. In our experiment we managed to create a system which can practically measure the PSF distribution. We demonstrated that is it is non-uniform. In this paper we represent the development of a novel sub-micrometer electron beam profile monitor based on the measurements of the PSF structure. The visibility of the structure is sensitive to micrometer electron beam dimensions. In this report we shall represent the recent experimental results. The future plans on the optimization of the monitor will also be presented.
KEK, Ibaraki
JAI, Egham, Surrey
INPR, Tomsk
TPU, Tomsk
RISE, Tokyo
High-brightness and reliable sources in the VUV and the soft X-ray region may be used for numerous applications in such areas as medicine, biology, biochemistry, material science, etc. 4th generation light sources based on X-ray free electron lasers are being built in a few world's leading laboratories. However, those installations are very expensive and the access to wider community is very limited. We propose a new approach to produce the intense beams of X-rays in the range of less than 500 eV based on compact electron accelerator. An ultimate goal of the project is to create a compact soft X-ray source based on Thomson scattering of Coherent Diffraction Radiation (CDR) using a small accelerator machine. CDR is generated when a charged particle moves in the vicinity of an obstacle. The radiation is coherent when its wavelength is comparable to or longer than the bunch length. The CDR waves will be generated in an opened resonator formed by two mirrors. In this report we represent the status of the experiment. The pilot experimental results and general hardware design will be demonstrated.
KEK, Ibaraki
FAIS, Akatsuka, Tsukuba, Ibaraki
A new type of rotating anticathode X-ray generator has been developed, in which the electron beam irradiates the inner surface of a U-shaped Cu anticathode. A high-flux electron beam is focused on the inner surface of the anticathode by optimizing the geometry of the bending magnet. In order to minimize the sizes of the X-ray source, the electron beam is focused in a short distance by the combined function magnets. A shape on the surface of the bending magnet was determined by simulation. The beam trajectories and bending magnet were optimized by the General Particle Tracer(GPT) and Opera-3D code simulation. The result of simulation clearly shows that the bending magnet gap surface angle parameters are important to the beam focused in a short distance. FWHM sizes of the beam from the simulation were obtained to be 0.45mm(horizontal) and 0.05mm(vertical) of which the anticathode with a beam voltage and current were 120kV and 75mA, respectively. The effective brilliance to be about 500kW/mm2 simulated predict that with the supposition of a two-dimensional Gaussian distribution. In this paper, the optimization of the focusing magnet and the results of the prototype test are reported.
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).
KAERI, Daejon
Uniform irradiation is very important for many kinds of experiments of proton beam utilization. In general, scanning magnet have been used for the uniform irradiation of high energy proton beam in the type of wobbler scanning, raster scanning, spiral scanning, etc. In the case of using magnets, it is not easy and needs high cost to install and operate because the magnet size and power become bigger with increase of beam energy accordingly. In this paper, we proposed simpler method and apparatus for uniform irradiation using 2D motional stage. It is composed of two motion systems for X- and Y- direction motion and goniostage. The maximum area is 20cm x 20cm and the incident angle can be controlled from +15 to -15 degree. Maximum sample weight have to be less than 5kg. In this paper, preliminary results for simple wobbler scanning is shown when the proton energy and beam current are about 40MeV and 1~10 nA respectively. The uniform scanning area was checked by using GAF film, MD-55 or HD-810. The stage can be used for the beam alignment and beam profile measurement at any position of beam line.
KAERI, Daejon
The solid target of the RFT-30 30 MeV cyclotron in KAERI was designed to produce the metalic radioisotopes, such as Zn-62, Cu-67, Ge-68, Pd-103, and In-111. The target control system should provide high reliability to prevent any kind of failure. Moreover, the operating procedures and maintenance cycle should be optimized and well organized to cover the unexpected situations. In this study, a simulation of the control system for the solid target in KAERI was carried out to confirm the operability of the solid target transport system. The receiving and irradiation stations are connected each other through square tube, and the control software was also checked. The developed solid target control system controls vacuum, cooling, and the whole procedures before, during, and after the irradiation.
University of Huddersfield, Huddersfield
Manchester University, Manchester
STFC/RAL, Chilton, Didcot, Oxon
GEANT4 provides an extensive set of alternative hadronic models. Simulations of the ISIS muon production using three such models applicable in the energy range of interest are presented in this paper and compared with the experimental data.
University of Huddersfield, Huddersfield
Manchester University, Manchester
STFC/RAL, Chilton, Didcot, Oxon
ISIS is the world's most successful pulsed spallation neutron source that provides beams of neutrons and muons that enable scientists to study the properties of the matter at the atomic level. Restrictions are imposed on the muon target regarding thickness as this will affect the proton transmission to the second neutron target. However, it could be possible to improve the muon production by optimizing the target geometry. Currently the muon target is a 7 mm thick graphite plate oriented at 45 degrees with respect to the proton beam. A set of slabs placed at variable distance is proposed instead of the 7 mm thick graphite target. The performance of the set of slabs is examined in this paper.
University of Huddersfield, Huddersfield
Manchester University, Manchester
STFC/RAL, Chilton, Didcot, Oxon
The ISIS neutron spallation source uses a separate muon target 20 m upstream of the neutron target for MuSR research. Because ISIS is primarily a neutron source, it imposes restrictions upon the muon target, which normally are not present at other muon facilities like PSI or TRIUMF. In particular it is not possible to use thicker targets and higher energy proton drivers because of the loss of neutrons and the increased background at neutron instruments. In this paper we investigate possible material choices for the ISIS muon target for increased muon yield.
University of Huddersfield, Huddersfield
Manchester University, Manchester
The European Spallation Source (ESS) is one of Europe's biggest and most prestigious science projects to design and construct the next generation facility for research with neutrons. ESS will be the world's most powerful spallation source and it will provide a unique tool for research into the atomic structure and dynamics of matter. We investigate the effects of the dimensions of the ESS spallation target on the total neutron yield integrated over the neutron energy and emission angle. We also investigate different material choices for the ESS target.
University of Huddersfield, Huddersfield
Manchester University, Manchester
STFC/RAL, Chilton, Didcot, Oxon
Simulations studies have been carried out to examine the impact of the energy of the proton driver on muon production. The muon flux is calculated as a function of proton energy over a wide range, which covers the energies at the existing muon and neutron facilities worldwide. The muon and higher energy pion yields are normalised per beam current and accelerator power. The case of a higher energy of the proton driver at the ISIS muon facility is also examined.
LBNL, Berkeley, California
Fermilab, Batavia
BNL, Upton, Long Island, New York
Advanced superconductors such as Nb3Sn are being considered for future magnet upgrades of the Large Hadron Collider (LHC) at CERN. The US LHC Accelerator Research Program (LARP) has developed a large bore (120mm) Nb3Sn IR quadrupole (HQ) capable of reaching 15 T at its conductor and a gradients of 199T/m at 4.4K and 219T/m at 1.9K. HQ is addressing coil alignment and accelerator field quality in a shell-based mechanical structure. In this paper we summarize the fabrication, assembly and initial test results of the 1 m long two-layer magnet.
Air Liquide, Division Techniques Avancées, Sassenage
F4E, Barcelona
STFC/RAL/ISIS, Chilton, Didcot, Oxon
ANSTO, Menai, New South Wales
Thanks to its experience in past projects in the field of neutron sources, Air Liquide DTA was involved in recent years in two major projects : a new Cold Neutron Source (OPAL) at ANSTO, Australia and a Spallation Neutron Source at ISIS, United Kingdom. The OPAL CNS is a liquid deuterium moderated source operating with a cold box with a refrigeration capacity of 5 kW at 25K designed and manufactured by Air Liquide DTA. ISIS Target Station 2 is a liquid hydrogen and solid methane moderated source for which Air Liquide DTA provided two Helium cold boxes (about 600W) operating at 20K derived from the standard Helial product, one customised cryogenic hydrogen loop, and very specific remote dismountable cryogenic transfer lines. These two cryogenic systems were fully commissioned on Air Liquide DTA dedicated test area before delivery to the customers. The purpose of this paper is to give a compared overview of the design and testing of the proposed cryogenic systems for these two projects.
INFN/LNF, Frascati (Roma)
INFN-Roma, Roma
A neutron source, based on photo-neutron production, has been designed and is under construction to upgrade the electron/positron/photon DAΦNE Beam Test Facility (BTF). We present the feasibility study, the solution chosen and the optimization done in order to maximize the neutron/photon yield as well as the comparison between different simulation codes (FLUKA/GEANT4/MCNPX). The first experimental test is foreseen in March 2010.
University of Fukui, Faculty of Engineering, Fukui
KURRI, Osaka
As for BNCT (boron neutron capture therapy) medical applications, an accelerator-based intense thermal or epithermal neutron source has been strongly requested recently. A scaling type of FFAG accelerator with ERIT (energy/emittance recovery internal target) scheme has been developed for this purpose. In this scheme, the beam emittance degradation caused by the neutron production target are cured by ionization cooling method. In this presentation, recent beam study of ionization cooling and neutron production will be described.
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken
KEK/JAEA, Ibaraki-Ken
In J-PARC, Materials and Life Science experimental Facility (MLF) is aimed at promoting experiments using the world highest intensity pulsed neutron and muon beams which are produced at a thick mercury target and a thin carbon graphite target by 3-GeV proton beams, respectively. The first beam was achieved at the target without significant beam loss in May 2008. It is succeeded stable operation with beam power of larger than 300 kW. After beam irradiation, the residual dose of radiation on the beam transport line is remarkably small where the highest dose is 20 microSv/h. In order to confirm stable operation of the facility, especially for the wellness of the target, it is important to obtain the beam profile at the target. We developed new technique by using imaging plate which is attached on the target vessel by remote handling technique via master slave manipulators. It is found that the beam profile shows good agreement with the calculation. It is also found that the beam scattering effect on the muon production target shows good agreement with the simulation calculation.
Kyungpook National University, Daegu
POSTECH, Pohang, Kyungbuk
PAL, Pohang, Kyungbuk
CHEP, Daegu
We report the activities by using the pulsed neutron facility which consists of an electron linear accelerator, a water-cooled Ta target, and a 12-m time-of-flight path. It can be possible to measure the neutron total cross-sections in the neutron energy range from 0.01 eV to few hundreds eV by using the neutron time-of-flight method. A 6LiZnS(Ag) glass scintillator was used as a neutron detector. The neutron flight path from the water-cooled Ta target to the neutron detector was 12.1 m. The background level was determined by using notch-filters of Co, In, Ta, and Cd sheets. In order to reduce the gamma rays from Bremsstrahlung and those from neutron capture, we employed a neutron-gamma separation system based on their different pulse shapes. The present measurements of several samples (Dy, Nb) are in general agreement with the evaluated data in ENDF/B-VII. The resonance parameters were extracted from the transmission data from the SAMMY fitting and compared with the previous ones. We also report the isomeric yield ratios for isomeric pairs produced from photonuclear reactions by using the bremsstrahlung photons from the 70-MeV electron linac.
BNL, Upton, Long Island, New York
For improved reproducibility of good operating conditions and ramp commissioning efficiency, new dual-plane slow orbit feedback during the energy ramp was implemented during run-10 in the Relativistic Heavy Ion Collider (RHIC). The orbit feedback is based on steering the measured orbit, after subtraction of the dispersive component, to either a design orbit or to a previously saved reference orbit. Using multiple correctors and beam position monitors, an SVD-based algorithm is used for determination of the applied corrections. The online model is used as a basis for matrix computations. In this report we describe the feedback design, review the changes made to realize its implementation, and assess system performance.
IAP, Frankfurt am Main
IKF, Frankfurt-am-Main
An intense 2 MeV, 200 mA proton beam will drive a neutron source by the reaction Li7(p,n)Be7 on solid as well as on liquid lithium targets. Actually, the facility is under construction at the physics faculty new experimental hall in Frankfurt. To study in detail the burning of elements in stars by the s-process, a pulsed beam operation with a bunch compressor at the linac exit will offer several Ampere beam current within 1 ns pulse length and with 250 kHz rep. rate at the n - production target. As the upper limit of generated neutrons and the total n- flux at this source are well defined the sample for neutron capture measurements can be placed after a time of flight path as short as 0.8 m only. This will provide highest accessible pulsed neutron flux rates for neutron energies in the 1 - 500 keV range. The highly space charge dominated bunch forming process as well as the ion source, the rf coupled 175 MHz RFQ/DTL - resonator and the target development will be explained.
JAEA/LINAC, Ibaraki-ken
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken
JAEA, Ibaraki-ken
KEK, Ibaraki
RAS/INR, Moscow
J-PARC, KEK & JAEA, Ibaraki-ken
The mass production of the ACS (Annular Coupled Structure) cavity started from March 2009 for the J-PARC Linac energy upgrade from 181 MeV to 400 MeV. This upgrade project requires 18 ACS accelerating modules and two debunchers additionally within three years. The construction schedule is so tight that we have to optimize the fabrication process. For example the geometrical beta is varied for each accelerating module, thus the several test cells were fabricated and for the all beta before the mass production to confirm the initial design and the frequency tuning procedure. This paper describes our approach for the mass production and the current status and results.
TUB, Beijing
LANL, Los Alamos, New Mexico
IHEP Beijing, Beijing
NUCTECH, Beijing
CIAE, Beijing
Institute of Physics, Chinese Academy of Sciences, Beijing
IMP, Lanzhou
Tsinghua University, Beijing
CERN, Geneva
This paper reports the design and construction status, technical challenges, and future perspectives of the proton-linac based Compact Pulsed Hadron Source (CPHS) at the Tsinghua University, Beijing, China.
PSI, Villigen
A new current monitor (MHC5) based on a re-entrant cavity tuned at the 2nd RF harmonic (101.26 MHz) has been in operation since April 2009 at PSI. It monitors the current of the high intensity 590 MeV proton beam at 8 m downstream of the graphite meson production target (TgE). The scattered particles and their secondaries from TgE introduce a heavy thermal load approximately of 230 W on MHC5 at 2 mA beam intensity, which is carried away by active water cooling. The inhomogeneous temperature profile in MHC5 results in thermomechanical deformations which leads to a change in its HF electromagnetic characteristics. Indeed, an anomalous RF drifts were observed during initial operations, which had to be compensated for, to obtain correct beam current monitoring. In this paper, the physics of the observed RF drift is analyzed by using advanced multiphysics simulation technologies.
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.
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.
IFMIF/EVEDA, Rokkasho
CEA, Gif-sur-Yvette
INFN/LNL, Legnaro (PD)
Fusion for Energy, Garching
CIEMAT, Madrid
JAEA, Rokkasho, Kamikita, Aomori
In the frame of the IFMIF/EVEDA project, a high-intensity (125 mA) CW deuteron accelerator will be installed and commissioned at the Rokkasho's Broader Approach (BA) site. The main objective of this 9 MeV prototype is to provide information on the feasibility of the design, the manufacturing and the operation of the two linacs (up to 40 MeV) foreseen for IFMIF*. Based on the requirements for each System (Accelerators, Lithium target and Tests Facility) which are deduced from the IFMIF fusion material irradiation requirements, given by the users, the objectives of this accelerator prototype are defined and presented here. Also, because of the distributed nature of the design work and the procurement of the accelerator, organization of the installation and commissioning phase is essential. The installation and commissioning schemes, the organization proposed and the overall plans are presented.
*IFMIF International Team, IFMIF Comprehensive Design Report (CDR) 2003.
ORNL, Oak Ridge, Tennessee
The chopper system for the Spallation Neutron Source (SNS) provides a gap in the beam for clean extraction from the accumulator ring. It consists of a pre-chopper in the low energy beam transport and a faster chopper in the medium energy beam transport (MEBT). It took several iterations to develop a working design with the required parameters. In this paper we describe the latest design of the MEBT chopper deflector and give results of the experimental verification of the chopper effectiveness, the gap cleanness and the rise time measured with high resolution using the SNS laser wire. The effect on the losses will be discussed as well.
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.
FZJ, Jülich
GSI, Darmstadt
Numerical studies of longitudinal filter and time-of-flight (TOF) cooling suggest that the strong mean energy loss due to an internal Pellet target in the High Energy Storage Ring (HESR) at the FAIR facility can be compensated by cooling and operation of a barrier bucket (BB) cavity. In this contribution detailed experiments at COSY to compensate the mean energy loss are presented. The internal Pellet target was similar to that being used by the PANDA experiment at the HESR. A BB cavity was operated and either TOF or filter stochastic momentum cooling was applied to cool a proton beam. Experimental comparisons between the filter and TOF cooling method are discussed. Measurements to determine the mean energy loss which is used in the simulation codes are outlined. The experiments proved that the mean energy loss can be compensated with a BB cavity. Results are compared with numerical tracking simulations which include the synchrotron motion in a barrier bucket as well as in an h = 1 cavity and stochastic momentum cooling. A detailed discussion of the tracking simulation code will be outlined in a separate contribution to this conference.
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..
Nagaoka University of Technology, Nagaoka, Niigata
FZJ, Jülich
GSI, Darmstadt
A small momentum spread of proton beam has to be realized and kept in a storage ring during an experiment with a dense internal target such as a pellet target. A stochastic cooling alone does not compensate the mean energy loss by the internal target. Barrier bucket operation will cooperate effectively the energy loss. In addition, the further small momentum spread can be realized with use of an electron cooling. In the present study, the simulation results on the simultaneous use of stochastic cooling and electron cooling at COSY are presented.
IHEP Beijing, Beijing
IHEP Beiing, Beijing
The analytic solution of a microchannel target for a uniform beam is given in one-dimentional model. The target surface temperature, maximum acceptable power density, and the function of various geometric parameter are deduced. The solution is modified for an axi-symmetric Gaussian beam. The analytic results are coincident with the numerical solution. A slit target used to measure beam energy spectrum for a beam with energy of 3.54MeV, average beam power of 36kW is developed.
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.
ICEPP, Tokyo
KEK, Ibaraki
University of Tokyo, Tokyo
In this paper, we describe a system design and current status of Shintake beam size monitor. Shintake monitor is a laser-based beam diagnostics tool, which provides a non-invasive measurement of transverse beam sizes. The interaction target probing the electron beam is interference fringes build up by the two coherent lasers that have narrow bandwidth and long coherent length. A scale of the target structure corresponds to approximately one fourth of the laser wave length, and the smallest measurable size reaches down to several tens of nanometers. The monitor we described here is installed at the virtual interaction point of the ATF2 beam line, which is built to confirm the proposed final focus system for Future Linear Colliders. We adopt second harmonics of Nd:YAG laser of 532 nm wavelength, and phase stabilization feedback system to allow to measure the designed beam size of about 37 nm. To widen a measurable range up to about 5 microns (wire scanner's range), we also prepare three crossing modes that change an effective wavelength for the fringes. The monitor is used to measure a focus size during the tuning process. The system is based on the Shintake monitor for FFTB.
KEK, Tsukuba
RCNP, Osaka
Optical beam measurement such as OTR(Optical Transition Radiation), ODR(Optical Diffraction Radiation), gas Cerenkov, and so on is a powerful tool to observe a two-dimensional information of high intensity beam profile, so that this method is widely used at various electron and hadron accelerators. However, high radiation field to damage an optical system gradually becomes a major issue with increasing the beam intensity to explore new physics. Our present effort is devoted to develop a high efficient optical system to resist such high radiation field. We newly designed an optical system composed of two spherical mirrors which do not have any lenses vulnerable to radiation. Detailed optics design and a result of optical performance test will be presented. Also we will report a result of a beam test experiment of this optics system combined with an OTR screen performed at high intensity proton extraction beamline of the J-PARC.
SSRF, Shanghai
Bunch charge uniformity control is very important for storage ring top-up operation. In order to monitor filling pattern and measure bunch charge precisely an PXI waveform digitizer based data acquisition system was developed to retrieve bunch charge information from BPM pickup signals. Effective sampling rate could be extended to 400GHz by waveform rebuilding technology, which folds multi turns data into single turn with real time sampling rate of 8GHz. Online evaluation shows charge resolution could be better than 0.5% for 1nC range.
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.
TPU, Tomsk
Tomsk Polytechnic University, Nuclear Physics Institute, Tomsk
A noninvasive technique to determine a sub-mm length of electron bunches (rms < 100 um) based on a measurement of the coherent Cherenkov radiation (CChR) spectrum in THz range is proposed. CChR is generated when electron bunch moves in a vacuum near dielectric target. If the optical properties and geometry of a target are chosen in order to achieve a low absorption with a dispersion allowing expanding the Cherenkov cone, such target may be considered as the «natural Cherenkov prism». We demonstrated a feasibility of using of CsI prism for measurement of a bunch length in the range 50-200 um for Lorentz factor = 100. We also measured CChR power from Teflon target generated by the 6.1 MeV bunched electron beam with bunch rms length 1.2 mm and compared it with coherent diffraction radiation one for identical conditions. CChR seems to be a promising radiation mechanism for a new beam diagnostics technique.
Fundación TEKNIKER, Eibar (Gipuzkoa)
Bilbao, Faculty of Science and Technology, Bilbao
STFC/RAL/ISIS, Chilton, Didcot, Oxon
A Front End Test Stand is being built at the Rutherford Appleton Laboratory in the UK to demonstrate a chopped H− beam of sufficiently high beam quality for future high-power proton accelerators (HPPA). The test stand consists on a negative Hydrogen ion source, a solenoid LEBT, a 324 MHz four vane RFQ, a MEBT composed of rebunching cavities and choppers and a set of diagnostics ending with a beam stop. The beam stop, which has to accept a 3 MeV, 60 mA, 2 ms, 50 Hz (10% duty factor) H− beam, consists of a coaxial double cone configuration where the inner cone's inner surface is hit by the beam and the inter-cone gap is cooled by high-speed water. The cones are situated inside a water tank and mounted at one end only to allow thermal expansion. In order to minimize both prompt and induced radiation pure aluminium is used, but the poor mechanical properties of pure aluminium are overcome by employing a metal spinning process that increases the yield strength to several times the original value of the non-deformed material. CFD and FEM codes have been used to avoid high temperature gradients, to minimize thermal stresses, and to minimize fatigue caused by the pulsed beam.
IFIC, Valencia
SLAC, Menlo Park, California
In this paper we describe the design, installation and first calibration tests of a Multi Optical Transition Radiation (OTR) monitor system in the beam diagnostic section of the Extraction (EXT) line of ATF2, close to the multi wire scanner system. This system will be a valuable tool for measuring beam sizes and emittances from the ATF Damping Ring (DR). With an optical resolution of about 2 um an original OTR design demonstrated the ability to measure a 5.5um beam size in one beam pulse and to take many fast measurements. This gives the OTR the ability to measure the beam emittance with high statistics, giving a low error and a good understanding of emittance jitter. Furthermore the near by wire scanners will be a definitive test of the OTR as a beam emittance diagnostic device. The muti-OTR system design proposed here is based on the existing OTR1X, located after the septums at the entrance of the EXT line.
PSI, Villigen
For high intensity beam operation (3mA, 1.8MW) in the PSI cyclotron, a new current monitor for proton beams has been installed during the 2009 maintenance period. This current monitor is an actively cooled re-entrant cavity with its resonance tuned at the 2nd RF harmonic (101 MHz). Operating this system presents several challenges due to the heavy shower of energetic particles, the resonator being placed 8 m behind a graphite target. The resonator is actively cooled with water, its external surface was blackened to improve the radiation cooling and its mechanical structure was optimized for good heat conduction. The resonance characteristics are extremely sensitive to structural changes of the resonator. Because of non-uniform temperature distribution and dynamical changes the observed gain drift during operation is of the order of 10%. To correct these drifts 2 tests signals 50 kHz off the RF frequency are measured on-line during beam operation. They provide an innovative mean to estimate and to correct on-line the resonator gain. This paper will present the measurement method and the achieved performances.
PSI, Villigen
ORNL, Oak Ridge, Tennessee
Operation and upgrade of very intense proton beam accelerators like the PSI facility and the SNS spallation source at ORNL is typically constrained by potentially large machine activation. Besides the standard beam diagnostics, beam tomography techniques provide a reconstruction of the beam transverse phase space distribution, giving insights to potential loss sources like irregular tails or halos. Unlike more conventional measurement approaches (pepper pot, slits) beam tomography is a non destructive method that can be performed at high energies and, virtually, at any beam location. Results from the application of the Maximum Entropy Tomography (MENT) algorithm to different beam sections at PSI and SNS will be shown. In these reconstructions the effect of nonlinear forces is made visible in a way not otherwise available through wire scanners alone. These measurements represent a first step towards the design of a beam tomography implementation that can be smoothly employed as a reliable diagnostic tool.
JAI, Egham, Surrey
CERN, Geneva
Royal Holloway, University of London, Surrey
A setup for the investigation of Coherent Diffraction Radiation (CDR) from a conducting screen as a tool for non-invasive longitudinal electron beam profile diagnostics has been designed and installed in the Combiner Ring Measurement (CRM) line of the CLIC Test Facility (CTF3, CERN). In this report the status of the monitor development and results on the interferometric measurements of CDR spectra are presented. The CDR signal correlation with an RF pickup and a streak camera is reported. The future plans for the system improvements are also discussed.
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.
University of Notre Dame, Notre Dame
Royal Holloway, University of London, Surrey
JAI, Egham, Surrey
KEK, Ibaraki
SLAC, Menlo Park, California
The demonstration of the stability of the position of the focused beam is a primary goal of the ATF2 project. We have installed a laser interferometer system that will eventually correct the measurement of high-precision Beam Position Monitors used in the ATF2 Final Focus Steering Feedback for mechanical motion or vibrations. Here, we describe the installed system and present preliminary data on the short- and long-term mechanical stability of the BPM system.
PSI, Villigen
CIAE, Beijing
With an average beam power of 1.3MW the PSI proton accelerator facility is presently at the worldwide forefront of high intensity accelerators. This talk describes critical aspects and recent improvements related to generation and transport of the high intensity beam in a cyclotron based facility. The installation of new accelerating resonators in the second of two cyclotrons led to a significant improvement in view of beam intensity but also the reliability of the facility. Besides the overall performance and further upgrade plans the discussed topics include: space charge dominated beam dynamics, beam loss handling, activation and specialized technical interlock systems.
LANL, Los Alamos, New Mexico
Nearly all risks to future generations arising from long-term disposal of used LWR nuclear fuel are attributable to the transuranic elements and long-lived fission products, about 2% of its content. The transuranic elements of concern are plutonium, neptunium, americium, and curium. Long-lived (>100,000-year half-life) isotopes of iodine and technetium are also created by nuclear fission of uranium. If we can reduce or otherwise securely handle this 2% of the used fuel, the toxic nature of the remaining used fuel after a few centuries of cooling is below that of the natural uranium ore that was originally mined for nuclear fuel. Only a small fraction of the available energy in the fuel is extracted on a single pass and the majority of the 'problem wastes' could be burned in fast-neutron spectrum reactors or sub-critical accelerator driven transmuters. The goals of accelerator transmutation are some or all of the following: 1) to significantly reduce the impacts due to the minor actinides on the packing density and long-term radiotoxicity in the repository design, 2) preserve/use the energy-rich component of used nuclear fuel, and 3) reduce proliferation risk.
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.
KURRI, Osaka
University of Fukui, Faculty of Engineering, Fukui
World's first ADSR experiments which use spallation neutrons produced by high energy proton beams accelerated by the FFAG synchrotron has started since March 2009 at KURRI. In these experiments, the prompt and delayed neutrons which indicate neutron multiplication caused by external source have been detected. The accelerator complex for ADSR study in KURRI consists of three FFAG proton rings. It delivers the 100MeV proton beam to the W target located in front of the subcritical nuclear fuel system constructed in the reactor core of KUCA (Kyoto University Critical Assembly) at 30Hz repetition rate. Current status of the facility and the future plans of ADSR system and high intensity pulsed spallation neutron source which employ a newly added 700MeV FFAG synchrotron to the existing FFAG complex in KURRI will be presented.
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.
GSI, Darmstadt
IPCP, Chernogolovka, Moscow region
Universidad de Castilla-La Mancha, Ciudad Real
CERN, Geneva
Safety of the personnel and the equipment is an issue of great concern when operating with mighty particle beams like the ones generated by the LHC. Any uncontrolled release of even a very small fraction of the beam energy could cause considerable damage to the equipment. A worst case scenario is in which the entire beam is lost at a single point. Over the past years, we have carried out extensive numerical simulations to assess the consequences of an accident of this magnitude. We have simulated the thermodynamic and the hydrodynamic response of cylindrical targets made of solid copper and solid graphite, respectively, that are facially irradiated with one LHC beam. Our simulations show that the 7 TeV/c LHC protons will penetrate up to about 35 m in solid copper and about 10 m in solid graphite during the 89 μs beam duration time. In both cases, the target is severely damaged and a substantial part of the target is converted into High Energy Density Matter state.
RIKEN/SPring-8, Hyogo
JASRI/SPring-8, Hyogo-ken
This paper describes the present status of a precise temperature-regulation system for the C-band accelerator at XFEL (X-ray Free Electron Laser)/SPring-8. It is essential to maintain a constant temperature of an rf cavity for stable lasing. We therefore installed a heater-assembly unit into a cooling water circuit of each rf cavity. By controlling the heater power, the temperature of the cavity can be stabilized. We constructed a prototype of this system at the SCSS (SPring-8 Compact SASE Source) test accelerator to check its feasibility for the XFEL. The prototype significantly contributes to a stable supply of SASE to users. For the XFEL, we simplified this system in consideration of cost and controllability. For example, to make one regulation system simultaneously controlling two C-band accelerating structures was tried. Keeping a temperature variation as tight as ±0.02 K at any operational mode could be achieved by this system. The preliminary test results of the system are also reported in this paper.
LAL, Orsay
INFN/LNF, Frascati (Roma)
IN2P3 IPNL, Villeurbanne
Providing a high quality and sufficient high current positron beam for the ultra high luminosity B-factory SuperB is a major goal. In this paper a proposition for positrons production and capture scheme based on low energy electrons up to1 GeV is presented. For this technique, several types of flux concentrator used to capture the positrons are being studied. The following accelerating section bringing the positrons up to 280 MeV and the total yield for L-band and S-band type accelerators are given. Also the result of the benchmark between ASTRA and a LAL code based on Geant4 toolkit simulation is discussed.
CERN, Geneva
DESY, Hamburg
The quality of the injection into the LHC is monitored by a dedicated software system which acquires and analyses the pulse waveforms from the injection kickers, and measures key beam parameters and compares them with the nominal ones. The beam losses at injection are monitored on many critical devices in the injection regions, together with the longitudinal filling pattern and maximum trajectory offset on the first 100 turns. The paper describes the injection quality check system and the results from LHC beam commissioning, in particular the beam losses measured during injection at the various aperture limits. The results are extrapolated to full intensity and the consequences are discussed.
SLAC, Menlo Park, California
The Phase II upgrade to the LHC collimation system calls for complementing the 30 high robust Phase I graphite secondary collimators with 30 high Z Phase II collimators. The Phase II collimators must be robust in various operating conditions and accident scenarios. This paper reports on the final construction and testing of the prototype collimator to be installed in the SPS (Super Proton Synchrotron) at CERN. Bench-top measurements have demonstrated the device is fully operational and has the mechanical and vacuum characteristics acceptable for installation in the SPS.
Cockcroft Institute, Lancaster University, Lancaster
Tech-X, Boulder, Colorado
The design of RF cavities is a multivariate multi-objective problem. Manual optimisation is poorly suited to this class of investigation, and the use of numerical methods results in a non-differentiable problem. Thus the only reliable optimisation algorithms employ heuristic methods. Using an evolutionary algorithm guided by Pareto ranking methods, a crab cavity design can be optimised for transverse voltage (VT) while maintaining acceptable surface fields and the correct operating frequency. Evolutionary algorithms are an example of a parallel meta-heuristic search technique inspired by natural evolution. They allow complex, epistatic (non-linear) and multimodal (multiple optima and/or sub-optima) optimization problems to be efficiently explored. Using the concept of domination the solutions can be ordered into Pareto fronts. The first of which contains a set of cavity designs for which no one objective (e.g. the transverse voltage) can be improved without decrementing other objectives.
UMAN, Manchester
The collimation system of the LHC will be critical to its success, as the halo of high energy (7 TeV) particles must be removed in such a way that they do not deposit energy in the superconducting magnets which would quench them, or showers in the experiments. We study the properties of the LHC collimation system as predicted by the Merlin and Sixtrack/K2 simulation packages, and compare their predictions for efficiency and halo production, and the pattern of beam losses. The sophisticated system includes many collimators, serving different purposes. Both programs include energy loss and multiple Coulomb scattering as well as losses through nuclear scattering. The MERLIN code also includes the effects of wakefields. We compare the results and draw conclusions on the performance that can be achieved.
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)
CERN, Geneva
Electron-cloud is one of the main limitations for particle accelerators with positively charged beams of high intensity and short bunch spacing, as SPS at CERN. The Secondary Electron Yield (SEY) of the inner surface of the vacuum chamber is the main parameter governing the phenomenon. The effect could be eliminated by coating the magnets vacuum chambers with a material of low SEY, which does not require bake-out and is robust against air exposure. For such a purpose amorphous carbon coatings were produced by magnetron sputtering of graphite targets. They exhibit maximum SEY between 0.9 and 1.1 after air transfer to the measuring instrument. After 1 month air exposure the SEY rises to values between 1.1 and 1.4. Storage under nitrogen or by packaging in Al foil makes this increase negligible. The coatings have a similar XPS C1s spectrum for a large set of deposition parameters and exhibit an enlarged line-width compared to pure graphite. The static outgassing without bake-out depends on deposition parameters and is in a range from 1 to 10 times higher than that of stainless steel. Instead, electron stimulated outgassing is lower than for stainless steel and is dominated by CO.
LAL, Orsay
IN2P3 IPNL, Villeurbanne
CERN, Geneva
BINP SB RAS, Novosibirsk
IHEP Beijing, Beijing
The CLIC study considers the hybrid source using channeling as the baseline for unpolarised positron production. The hybrid source uses a few GeV electron beam impinging on a crystal tungsten target. With the tungsten crystal oriented on its < 111 > axis it results an intense, relatively low energy photon beam due mainly to channeling radiation. Those photons are then impinging on an amorphous tungsten target producing positrons by e+e- pair creation. The downstream capture section is based on an adiabatic matching device and a 2 GHz pre-injector linac. The resulting studies are presented here.
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.
JAEA, Rokkasho, Kamikita, Aomori
Control System for IFMIF/EVEDA accelerator prototype consists of the six subsystems; Central Control System (CCS), Local Area Network (LAN), Personnel Protection System (PPS), Machine Protection System (MPS), Timing System (TS) and Local Control System (LCS). The subsystems have been designed and their test benches been fabricated at JAEA. The IFMIF/EVEDA accelerator prototype provides a deuteron beam with the power more than 1 MW, which is as same as that in cases of J-PARC and SNS. In the control system, MPS and TS with high performance and precision are strongly required to avoid the radio-activation of the accelerator components. The prototypes of the MPS and TS are testing in conjunction with the injector test starting at CEA/Saclay from autumn in 2010. These results will feedback the design and the fabrication of the control components. This paper presents the development status of the TS modules and EPICS drivers for TS and MPS, and the prospects to apply them to the Injector test.
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken
KEK/JAEA, Ibaraki-Ken
A 3GeV Rapid-Cycling Synchrotron (RCS) in Japan Proton Accelerator Research Complex (J-PARC) has continuously provided more than 100kW proton beam to the Neutron target since October 2009. And we also successfully accelerated 300kW beam for one hour on December 10th by way of trial. We found some problems through these experiences. We report those problems and the residual dose in such high intensity operation.
ORNL, Oak Ridge, Tennessee
ORNL RAD, Oak Ridge, Tennessee
All stages of the SNS development require significant research and development work in the field of radiological shielding design to assure safety from a radiation-protection point of view for facility operation and to optimize accelerator and target performance. Here we present an overview of on-going shielding work and associated with it procedures and regulations. In the present time, the most of the shielding work is focused on the neutron beam lines and their instrument enclosures in order to commission and provide save operation in the future. This effort is performed according to the guidelines for shielding calculations of SNS neutron beam lines, which sets standards for the analyses and helps to prepare for the Instrument Readiness Review (IRR). The IRR ascertains that the instruments has been design, constructed, and installed to allow safe operation and maintenance. In addition, there is still support for the accelerator facility to redesign parts of the accelerator structures, to design shielding for removed components and test stands for accelerator structures, and for radiation protection analyses for evaluations of accelerator and target safety systems.
LAL, Orsay
DESY, Hamburg
INFN/LNL, Legnaro (PD)
CSIC, Madrid
LAL-Orsay is developing an important effort on R&D and technology studies on RF power couplers for superconductive cavities. One of the most critical components of those devices is the ceramic RF window that allows the power flux to be injected in the coaxial line. The presence of a dielectric window on a high power RF line has a strong influence on the multipactor phenomena. The most important method to reduce the multipactor is to decrease the secondary emission yield of the ceramic window. Due to its low Secondary electron Emission Yield (SEY), TiN thin film is used as a multipactor suppressor coating on RF ceramic coupler windows. In this frame work, TiN deposition was made by magnetron reactive sputtering. XPS and XRD analysis were performed to control the film composition and stoechiometry. Coating thickness was optimized so that the TiN coating effectively reduces the SEY but does not cause excessive heating, due to ohmic loss. For this purpose, SEY measurements on covered and uncovered TiN Alumina substrates, multipactor level breakdown on TiN coated Cupper substrates and RRR measurements were performed for different deposit thicknesses.
IHEP Beijing, Beijing
HJL, Beijing
BIAM, Beijing
Ningxia Orient Tantalum Industry Co., Ltd., Dawukou District, Shizuishan city
IHEP Beiing, Beijing
The combination of the low-loss shape and large grain niobium material is expected to be the possible way to achieve higher gradient and lower cost for ILC 9-cell cavities. As the key component of the 'IHEP 1.3 GHz SRF Accelerating Unit and Horizontal Test Stand Project', a low-loss shape 9-cell cavity using Ningxia large grain niobium has been fabricated and surface treated at IHEP and will be tested at KEK. The fabrication procedure, surface treatment recipes as well as the SRF facilities are presented in this paper.
CERN, Geneva
Cockcroft Institute, Lancaster University, Lancaster
Niobium thin film cavities have shown good and reliable performance for LEP and LHC, although there are limitations to overcome if this technique should be used for new accelerators such as the ILC. New coating techniques like High Power Impulse Magnetron Sputtering (HiPIMS) has shown very promising results and we will report on its possible improvements for Nb thin film cavity performance. Current materials used in accelerator SRF technologies operate at temperatures below 4 K, which require complex cryogenic systems. Researchers have investigated the use of High Temperature Superconductors (HTS) to form RF cavities, with limited success*. We propose a new approach to achieve a high-temperature SRF cavity based on the superconducting 'proximity effect'**. The superconducting proximity effect is the effect through which a superconducting material in close proximity to a non-superconducting material induces a superconducting condensate in the latter. Using this effect we hope to overcome the problems that have prevented the use of HTS for accelerating structures so far. We will report the preliminary studies of magnetron sputtered thin films of Cu on Nb.
* E. J. Minehara et al, Superconductivity 3, p277 (1990)
** R. Seviour et al, Superlattices and Microstructures, 25, p647 (1999)
ODU, Norfolk, Virginia
Using high-pressure RF cavities for muon colliders would provide higher accelerating gradients, that is crucial for fast acceleration of short-living muons .This approach requires a good evaluation for mechanisms of muon - low-Z gas interaction, including such effects as multiple scattering and space charge effects. Most present simulation tools (GEANT4, G4MICE) for muon beams are based on single particle tracking, where collective effects are not taken into account. We use a modified molecular dynamic simulation technique to study effects of both multiple scattering and space charge screening by the gas on scattering, energy loss, and propagation of muons during both ionization cooling and acceleration.
NSRRC, Hsinchu
Shimming magnetic field error on each pole in the Elliptically Polarized Undulator (EPU) is a time-consuming work and highly based on experience without scientific systematic methods. Therefore, an auto-field shimming program is developed to save time on pole shimming process. The program is including two major steps to analyze where the poles is defective or imperfect. Step one is to clarify the magnetic pole quality. If its quality is far away to user-defined standards, we change the pole instead of processing to balance them relatively for uniform magnetic field. The magnetic pole quality is based on deltaB/Bavg and deltaI/Iavg(half period of integral) percentage. The second step is to build the effective field and once integral model of pole and permanent magnet calculation. If we shim the defective pole by moving vertically and transversely, it would surge intrinsic change of the deltaB/Bavg and deltaI/Iavg at defective and surrounded poles. Auto-field shimming algorithm would assist us to plan shimming strategies to deal with magnetic poles.
Diamond, Oxfordshire
Diamond Light Source is currently operating with two multipole superconducting wigglers, one with 49 poles at 3.5 T and another with 49 poles at 4.2 T. The cryogenic arrangement is similar in both cases; each cryostat contains a liquid helium bath cooled by four cryocoolers. The design goal was to allow up to six months continuous operation in the storage ring between refilling the liquid helium bath. However, the helium boil-off is much higher than expected, necessitating much more frequent refills. As well as having a cost implication, this also currently poses a restriction on the operating beam current. In this report we present the results of measurements carried out under various beam conditions to try to understand the reason for the higher boil-off in terms of heat load seen by the cryostat and effective cryocooler performance. We also present our plans for dealing with the problem in the near and longer term.
KEK, Ibaraki
We are developing large grain/single crystal niobium material for ILC collaborating with Tokyo Denkai. These materials are very much promising to obtain high SRF cavity performance with cost-effective production. We have fabricated two 9-cell cavities from these large grain niobium materials and made cold test to evaluate the SRF performance. In this paper, we will report cavity fabrications and preparations and cold test results.
Imperial College of Science and Technology, Department of Physics, London
Muon ionization cooling provides the only practical solution to prepare high brilliance beams necessary for a neutrino factory or muon colliders. The muon ionization cooling experiment (MICE)* is under development at the Rutherford Appleton Laboratory (UK). It comprises a dedicated beam line to generate a range of input emittance and momentum, with time-of-flight and Cherenkov detectors to ensure a pure muon beam. A first measurement of emittance is performed in the upstream magnetic spectrometer with a scintillating fiber tracker. A cooling cell will then follow, alternating energy loss in liquid hydrogen and RF acceleration. A second spectrometer identical to the first one and a particle identification system provide a measurement of the outgoing emittance. In May 2010 it is expected that the beam and most detectors will be commissioned and the time of the first measurement of input beam emittance closely approaching. The plan of steps of measurements of emittance and cooling, that will follow in the rest of 2010 and later, will be reported.
This abstract is submitted by the chear of the MICE speaker bureau. A member of the collaboration will be soon identified to present the poster and added a co-author.
Osaka University, Osaka
The COMET is an experiment to search for the process of muon to electron conversion in a muonic atom, and is in its design phase to be carried out at J-PARC in near future. The experiment uses a long superconducting solenoid channels from a pion production target to a detector system. In order, to study the solenoid channel the g4beamline is used for the magnetic field calculation and beam tracking. This paper reports the status of the simulation studies.
STFC/RAL/ASTeC, Chilton, Didcot, Oxon
Imperial College of Science and Technology, Department of Physics, London
CERN, Geneva
Fermilab, Batavia
BNL, Upton, Long Island, New York
Muons, Inc, Batavia
LBNL, Berkeley, California
We discuss alternative designs of the muon capture front end of the Neutrino Factory International Design Study (IDS). In the front end, a proton bunch on a target creates secondary pions that drift into a capture channel, decaying into muons. A sequence of RF cavities forms the resulting muon beams into strings of bunches of differing energies, aligns the bunches to (nearly) equal central energies, and initiates ionization cooling. This design is affected by limitations on accelerating gradients within magnetic fields. The effects of gradient limitations are explored, and mitigation strategies are presented.
Imperial College of Science and Technology, Department of Physics, London
OXFORDphysics, Oxford, Oxon
In the Muon Ionization Cooling Experiment (MICE) at RAL muons are produced and transported in a dedicated beamline connecting the production point (target) to the diffuser, a mechanism inside the first spectrometer solenoid designed to inflate the initial normalized emittance up to 10 mm rad in a controlled fashion. In order to match the incoming muons to the downstream experiment, covering all the possible values of the emittance-momentum matrix, an optimisation procedure has been devised which is based upon a genetic algorithm coupled to the tracking code G4Beamline. Details of beamline tuning and initial measurements are discussed.
Imperial College of Science and Technology, Department of Physics, London
STFC/RAL/ISIS, Chilton, Didcot, Oxon
The international Muon Ionisation Cooling Experiment (MICE) is designed to provide a proof of principal of the ionisation cooling technique proposed to reduce the muon beam phase space at a future Neutrino Factory or Muon Collider. The pion production target is a titanium cylinder that is dipped into the proton beam of the Rutherford Appleton Laboratory's ISIS 800 MeV synchrotron. Studies of the particle rate in the MICE muon beam are presented as a function of the beam loss induced in ISIS by the MICE target. The implications of the observed beam loss and particle rate on ISIS operation and MICE data taking is discussed.
Imperial College of Science and Technology, Department of Physics, London
Fermilab, Batavia
The COherent Muon to Electron Transition (COMET) experiment aims to measure muon to electron conversion with an unprecedented sensitivity of less than 1 in 10 million billion. The COMET experiment was given stage 1 approval by the J-PARC Program Advisory Committee in July 2009 and work is currently underway towards preparing a technical design report for the whole experiment. The need for this sensitivity places several stringent requirements on the beamline, such as, a pulsed proton beam with an extinction level between pulses of 9 orders of magnitude; a 5T superconducting solenoid operating near a high radiation environment; precise momentum selection of a large emittance muon beam and momentum selection and collimation of a large emittance electron beam. This paper will present the current status of the various components of the COMET beamline.
Sheffield University, Sheffield
The MICE experiment requires a beam of low energy muons to demonstrate muon cooling. A target mechanism has been developed that inserts a small titanium target into the circulating ISIS beam during the last 2ms before extraction. The target mechanism has been in operation in the ISIS beam during 2009 and a large set of useful data has been obtained describing the target's operational parameters. This has allowed the commissioning of the initial section of the MICE beam line and instrumentation, and the close monitoring of target performance. This work describes these target parameters and presents some of the results from operational shifts.
Sheffield University, Sheffield
STFC/RAL, Chilton, Didcot, Oxon
The MICE experiment uses a beam of low energy muons to test the feasibility of ionisation cooling. This beam is derived parasitically from the ISIS accelerator at the Rutherford Appleton Laboratory. A target mechanism has been developed and deployed that rapidly inserts a small titanium target into the circulating proton beam immediately prior to extraction without undue disturbance of the primary ISIS beam. The first target drive was installed in ISIS during 2008 and operated successfully for over 100,000 pulses. A second upgraded design was installed in 2009 and is currently in operation. The technical specification for this upgraded design is given and the motivation for many of the improvements is discussed. In addition possible future improvements to the current design are discussed.
Fermilab, Batavia
BNL, Upton, Long Island, New York
IIT, Chicago, Illinois
LBNL, Berkeley, California
An accelerator complex that can produce ultra-intense beams of muons presents many opportunities to explore new physics. A facility of this type is unique in that, in a relatively straightforward way, it can present a physics program that can be staged and thus move forward incrementally, addressing exciting new physics at each step. At the request of the US Department of Energy's Office of High Energy Physics, the Neutrino Factory and Muon Collider Collaboration and the Fermilab Muon Collider Task Force have recently submitted a proposal to create a Muon Accelerator Program that will have, as a primary goal, to deliver a Design Feasibility Study for an energy-frontier Muon Collider after a 7 year R&D program. This paper presents a description of a Muon Collider facility with a brief physics motivation, gives an overview of the proposal with respect to its organization and timeline and then discusses in some detail its major technical components.
Fermilab, Batavia
CERN, Geneva
STFC/RAL/ASTeC, Chilton, Didcot, Oxon
Muons, Inc, Batavia
We discuss the design of the muon capture front end of a neutrino factory and present studies of variations of its components. In the front end, a proton bunch on a target creates secondary pions that drift into a capture transport channel, decaying into muons. A sequence of rf cavities forms the resulting muon beams into strings of bunches of differing energies, aligns the bunches to (nearly) equal central energies, and initiates ionization cooling. The cooling section uses absorber material (reducing the 3-D muon momenta) alternating with rf cavities (restoring longitudinal momentum) within strong focusing magnetic fields. The design is affected by limitations on accelerating gradients within magnetic fields. The effects of gradient limitations are explored, and mitigation strategies are presented. Variations of the ionization cooling and acceleration scenarios and extensions toward use in a muon collider are discussed.
LANL, Los Alamos, New Mexico
We propose a high-gradient linear accelerator for accelerating low-energy muons and pions in a strong solenoidal magnetic field. The acceleration starts immediately after collection of pions from a target by solenoidal magnets and brings muons to a kinetic energy of about 200 MeV over a distance of the order of 10 m. At this energy, both an ionization cooling of the muon beam and its further acceleration in a superconducting linac become feasible. The project presents unique challenges ' a very large energy spread in a highly divergent beam, as well as pion and muon decays ' requiring large longitudinal and transverse acceptances. One potential solution incorporates a normal-conducting linac consisting of independently fed 0-mode RF cavities with wide apertures closed by thin metal windows or grids. The guiding magnetic field is provided by external superconducting solenoids. The cavity choice, overall linac design considerations, and simulation results of muon acceleration are presented. While the primary applications of such a linac are for homeland defense and industry, it can provide muon fluxes high enough to be of interest for physics experiments.
PU, Princeton, New Jersey
STFC/RAL/ASTeC, Chilton, Didcot, Oxon
STFC/RAL, Chilton, Didcot, Oxon
ORNL, Oak Ridge, Tennessee
CERN, Geneva
EBG MedAustron, Wr. Neustadt
BNL, Upton, Long Island, New York
Fermilab, Batavia
PPPL, Princeton, New Jersey
We report on the analysis of data collected in the MERIT experiment at CERN during the Fall of 2007. These results validate the concept of a free mercury jet inside a high-field solenoid magnet as a target for a pulsed proton beam of 4-MW power, as needed for a future Muon Collider and/or Neutrino Factory.
UCR, Riverside, California
Imperial College of Science and Technology, Department of Physics, London
Sofia University St. Kliment Ohridski, Faculty of Physics, Sofia
The Muon Ionization Cooling Experiment (MICE) is being built at the Rutherford Appleton Laboratory (RAL) to test ionization cooling of a muon beam. Successful demonstration of cooling is a necessary step along the path toward creating future high intensity muon beams in either a Neutrino Factory or Muon Collider. Production of particles in the MICE beamline begins with a titanium target dipping into the ISIS proton beam. The resulting pions are captured, momentum-selected, and fed into a 5T superconducting decay solenoid which contains the pions and their decay muons. Another dipole then selects the final particles for propagation through the rest of the MICE beamline. Within the last year, the MICE target has been redesigned, rebuilt, and has begun operating in ISIS. The decay solenoid has also become operational, dramatically increasing the number of particles in the MICE beamline. In parallel, particle identification detectors have also been installed and commissioned. In this paper, the commissioning of the improved MICE beamline and target will be discussed, including the use of Time-of-Flight detectors to understand the content of the MICE beam between 200 and 444 MeV/c.
STFC/RAL/ASTeC, Chilton, Didcot, Oxon
The neutrino factory requires a source of pions within a momentum window determined by the ‘muon front end' accelerator structure downstream. The technique of finding which parts of a large target block are net absorbers or emitters of particles may be adapted with this momentum window in mind. Therefore, analysis of a hadronic production simulation run using MARS15 can provide a candidate target shape in a single pass. However, changing the shape of the material also affects the absorption/emission balance, so this paper investigates iterative schemes to find a self-consistent optimal, or near-optimal, target geometry.
BNL, Upton, Long Island, New York
University of Warwick, Coventry
STFC/RAL, Chilton, Didcot, Oxon
UCLA, Los Angeles, California
ORNL, Oak Ridge, Tennessee
SUNY SB, Stony Brok, New York
PU, Princeton, New Jersey
We outline a program of engineering design and simulation for a target station and pion production/capture system for a 4-MW proton beam at the front end of a Muon Collider or a Neutrino Factory. The target system consists of a free liquid-metal (nominally mercury) jet immersed in a high-field solenoid magnet capture system that also incorporates the proton beam dump. Topics to be studied include optimization of proton beam and jet target parameters, of the magnetic configuration for capture and subsequent transport of pions and muons, of the beam dump, of the radiation/thermal shielding of the capture magnets, and of the beam windows.
BNL, Upton, Long Island, New York
By providing an extremely intense source of neutrinos from the decays of muons in a storage ring, a Neutrino Factory will provide the opportunity for precision measurements and searches for new physics amongst neutrino interactions. An active international collaboration is addressing the many technical challenges that must be met before the design for a Neutrino Factory can be finalized. An overview of the accelerator complex and the current international R&D program will be presented, and the key technical issues will be discussed.
CERN, Geneva
ESRF, Grenoble
Following the analysis of the results obtained during the first year of beam commissioning of the CERN multi-turn extraction, a number of changes have been introduced in the beam manipulations performed in the CERN Proton Synchrotron. This includes a different control of the linear chromaticity, the setting of the non-linear magnets used to split the beam, and the longitudinal structure in the PS. The results obtained during the 2009 run are presented and discussed in detail, including the beam performance in both the PS and the SPS, as well as the optics measurements in the transfer line between the two circular machines.
KEK, Ibaraki
Under the CERN-SLAC-KEK collaboration, we have been developing the high gradient TW accelerator structures. One of the main focuses is the feasibility study of CLIC accelerator structure at X-band. A high power facility, Nextef*, was established at KEK in 2007. A few structures have been tested, including an un-damped disk-loaded structure successfully tested beyond 100 MV/m, a heavily damped structure to be tested from late 2009 and a structure made in a quadrant configuration. These structures follow the same accelerating-mode RF parameter profile, called CLIC-C**, but show different features at high gradient operation. Various observables, such as dark current, vacuum activities, light emission, breakdown rate, and so on, are measured. We discuss the high gradient phenomena related to these observables and the possible improvement for stable operation at a higher gradient.
* T. Higo et al., THP038, LINAC06,2006.
**A. Grudiev, http://indico.cern.ch/conferenceDisplay.py?confId=30911
KEK, Ibaraki
In order to improve the capture efficiency of the positron produced at the target in present KEKB Injector linac, a new project has just started to utilize L-band (1298MHz) RF. The present S-band (2856MHz) capture cavities and successive three RF units are to be replaced by those of L-band. The specifications of the L-Band system should fulfill the demands of a positron damping ring downstream which is also to be under study for super KEKB project. Besides the whole design work of the system, our present ongoing work is rather concentrated on establishing L-Band RF source and accelerating structures.
JAEA, Ibaraki-ken
In the design of prototype RFQ linac for the IFMIF/EVEDA Project, a coupled cavity type of RFQ, which has a longitudinal length of 9.78m, was proposed to accelerate deuteron beam up to 5MeV. The operation frequency of 175MHz was selected to accelerate a large current of 125mA in CW mode. The driving RF power of 1.28 MW by 8 RF input couplers has to be injected to the RFQ cavity. As the RF input coupler design, RF losses including RF vacuum windows, based on a 4 1/16 inch and 6 1/8 inch co-axial waveguide as well as RF coupling factor of a loop antenna with varied insertion depths using an RFQ model were calculated. In this conference, these results and thermal analysis results in CW operation mode will be presented in details.
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.
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.
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
The beam loss caused by the nuclear scattering together with the multiple Coulomb scattering at the stripping foil is one of the key issue in RCS (Rapid Cycling Synchrotron) of the J-PARC (Japan Proton Accelerator Research Accelerator). In order to have a very realistic understanding, a systematic study with both experiment and simulation has been carried out recently. A total of seven targets with different thickness were used and the measured beam losses were found to be good in agreement with that in the simulation. A detail and realistic understanding from such a study will be very useful not only to optimize the foil system including the thickness and size at present with the injection beam energy of 181 MeV but also for the near future upgrade with 400 MeV and in addition can be a good example for similar existing and proposing projects.
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.
KEK, Tsukuba
Miyazaki University, Miyazaki
Tokyo City University, Tokyo
NIRS, Chiba-shi
The slow extraction beam from the J-PARC Main Ring (MR) to the Hadron Experimental Facility is used in various nuclear and particle physics experiments. A flat structure and low ripple noise are required for the spills of the slow extraction. The spill control system has been developed for the J-PARC slow extraction to make a flat structure and small ripple. It consists of the extraction quadrupole magnets and feedback device. The extraction magnets consist of two kinds of quadrupole magnets, EQ (Extraction Q-magnet) which make flat beam and RQ (Ripple Q-magnet) which reject the high frequent ripple noise. The feedback system, which is using Digital Signal Processor (DSP), makes a ramping pattern for EQ and RQ from spill beam monitor. The extraction magnets and feedback device were installed in September 2009, and spill feedback study were successfully started from the beam time in October 2009. Here we report the operation status of magnets and first study of beam commissioning with spill feedback.
CERN, Geneva
The High Radiation to Materials facility - thereafter HiRadMat - is designed to allow testing of accelerator components, in particular those of the LHC and its injectors, with the impact of high-intensity pulsed beams. The facility is currently under construction, as an approved CERN project. The installation of the dedicated primary beam line and experimental area is planned during the 2010-2011 CERN accelerator technical shutdown. It will be ready for users after commissioning and some initial running in October 2011. A detailed proton beam line design has been performed in order to fulfill the beam parameter specification, in particular the demanding optics flexibility at the test stand location. The studies presented include trajectory correction and aperture studies as well as specifications of magnetic systems, power converters, beam instrumentation and vacuum systems.
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.
NSC/KIPT, Kharkov
NESTOR facility that is under construction in NSC KIPT (Kharkov, Ukraine) consists of compact 225 MeV electron storage ring, 100 MeV linear accelerator-injector, laser optical system and radiation channel. To provide effective and cheap survey and alignment system for compact facility is crucial task in order to achieve designed X-ray parameters (X-ray intensity up to 1012 phot/s). In the article the survey and alignment strategy of Compton generator NESTOR is described. The system uses traditional triangulation method and provides the accuracy of technological equipment alignment equal to 100 mkm.
JAEA, Ibaraki-ken
JAEA APRC, Ibaraki-ken
JAEA/Kansai, Kyoto
ILE Osaka, Suita
The pointing stability and the divergence of a quasi-monoenergetic electron bunch generated in a self-injected laser-plasma acceleration regime were investigated. Gas-jet targets have been irradiated with focused 40 fs laser pulses at the 4-TW peak power. A pointing stability of 2.4 mrad root-mean-square (RMS) and a beam divergence of 10.6 mrad (RMS) were obtained using argon gas-jet target for 50 sequential shots, while these values were about three times smaller than at the optimum condition using helium. In particular, the peak electron energy was 9 MeV using argon, which is almost three times lower than that using helium. This result implies that the formation of the wake-field is different between argon and helium, and it plays an important role in the generation of a electron bunch. This stabilization scheme is available for another gas material such as nitrogen. At nitrogen gas-jet target, the pointing stability is more improved to 1.4 times smaller (1.7 mrad (RMS)) than that in argon gas-jet target and the peak energy is increased to grater than 40 MeV. These results prove that this method not only stabilize the e-beam but also allows controlling the electron energy.
DESY Zeuthen, Zeuthen
The development of an intense polarised positron sources provides a challenge for a new generation of linear colliders. The software framework Geant4, a toolkit for simulation of the passage of particles trough matter, features tracking capabilities of charged particles in electromagnetic fields, and also includes the description of polarisation transfer in scattering processes. Based on Geant4 a novel simulation tool, PPS-Sim*, has been developed to optimise the design and to determine polarisation, beam properties, as well as energy deposition in accelerator components. All source components and their parameters can be chosen easily and flexible. Helical undulator, laser-Compton and coherent Bremsstrahlung in crystals are available as positron production schemes. Target materials and geometry can be adjusted. Flux concentrator, quarter wave transformer and lithium lens are implemented as possible capture devices. Geometry, accelerating components and magnetic field configuration can be specified by the user. In this contribution, PPS-Sim will be presented, and selected results for linear collider applications will be discussed.
* PPS-Sim web page - http://pps-sim.desy.de
Osaka University, Osaka
KEK, Ibaraki
An intense muon beam is mandatory for the next-generation experiments to search for lepton flavor violating processes in the muon sector. The COMET experiment, J-PARC ·1021, aims to search for muon to electron conversion with an unprecedented sensitivity.. The muon beam is produced from pion decays in a strong magnetic field generated by superconducting solenoid coils. The large-bore superconducting coils enclose the pion-production target to capture pions with a large solid angle. The magnetic field is designed to have a peak of 5T at the target. To avoid severe radiation from the target, thick shielding is inserted in the warm bore of the pion capture solenoid magnet. The proton beam is injected through the gap between the pion capture solenoid and the subsequent transport solenoid magnets. For this purpose, the bore of the pion capture solenoid has to be larger than 1 m. This paper describes the design of the pion capture solenoid magnet for the COMET experiment.
Cockcroft Institute, Warrington, Cheshire
Lancaster University, Lancaster
LLNL, Livermore, California
Imperial College of Science and Technology, Department of Physics, London
The University of Liverpool, Liverpool
The efficiency of future positron sources for the next generation of high-energy particle colliders (e.g. ILC, CLIC, LHeC) can be improved if the positron-production target is immersed in the magnetic field of adjacent capture optics. If the target is also rotating due to heat deposition considerations then eddy currents may be induced and lead to additional heating and stresses. In this paper we present data from a rotating target wheel prototype for the baseline ILC positron source. The wheel has been operated at revolution rates up to 1800rpm in fields of the order of 1 Tesla. Comparisons are made between torque data obtained from a transducer on the target drive shaft and the results of finite-element simulations. Rotordynamics issues are presented and future experiments on other aspects of the positron source target station are considered.
Cockcroft Institute, Warrington, Cheshire
Lancaster University, Lancaster
The University of Liverpool, Liverpool
CLIC will need of order 10 to the 14 positrons per second to achieve its specified luminosity. For such a challenge, an undulator based scheme has been proposed as one of the options for the positron source. As CLIC may operate over a wide range of energy (from 0.5 TeV to 3 TeV), there is a large margin for us to push the performance of the whole system to be more efficient. We report on the undulator parameters and optimization of components of the source such as conversion target, AMD, solenoid and capture RF for different operational scenarios. In addition to maximizing the positron yield the polarization of the positron beam are also considered.
ANL, Argonne
We present an update on the ANL ILC positron source study. We examined the impact of different drive beam energies on the positron yield and polarization for the ILC RDR baseline undulator. The e+ yield is found to drop rapidly as the drive beam energy is reduced. We studied different undulator parameters for their effect on the positron yield and polarization when working at lower drive beam energies. Using a lower K (B field level) can increase the photon energy, but it is still very difficult to bring the yield up for low drive beam energies. For 250 GeV drive beam options, we studied the RDR undulator performance as a function of K. Instead of powering off some sections of the undulator, one can also consider lowering the B field to bring the positron yield back to the desired 1.5 e+/e-. We also studied the liquid lead target option for ILC positron source and the energy deposition in the reference design Ti target wheel.
LLNL, Livermore, California
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire
The positron source at a future TeV scale electron linear collider will need to generate positrons at a rate two orders of magnitude larger than have been previously achieved. We report on a design of a 3.5 Tesla pulsed flux concentrator magnet which uses liquid nitrogen cooling of the flux concentrator plates to reduce the electrical resistance leading to reduced energy deposition and the ability to generate the required 1 ms pulse duration. This magnet can double the collection efficiency of positrons emitted from the target.
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.
JAEA/TARRI, Gunma-ken
To achieve ultra-low-fluence large-area uniform irradiation of ion beams for advanced applications in the field of materials sciences and biotechnology, a uniform-beam irradiation system has been developed using multipole magnets at the Japan Atomic Energy Agency (JAEA) cyclotron facility. The system consists of a beam attenuator for the wide-range intensity control, an electrostatic beam chopper for the control of irradiation time, scattering foils for conditioning of the initial beam distribution, octupole magnets for transverse tail-folding, sextupole magnets for the correction of the beam misalignment, and the diagnostic station of the two-dimensional beam profile. In this paper, recent experimental results are described, especially on the formation of a beam with a uniform transverse distribution by the combination of the sextupole and octupole magnets.
Fermilab, Batavia
The NOνA project will upgrade the existing Neutrino at Main Injector (NuMI) project beamline at Fermilab to accommodate beam power of 700 kW. The Medium Energy (ME) graphite target assembly is provided through an accord with the State Research Center of Russia Institute for High Energy Physics (IHEP) at Protvino, Russia. The effects of proton beam energy deposition within beamline components are considered as thermal stability of the target carrier assembly and alignment budget are critical operational issues. Results of finite element thermal and structural analysis involving the target carrier assembly is provided with detail regarding the target's beryllium windows.
mcgee@fnal.gov
KEK, Tsukuba
RCNP, Osaka
In the hadron experimental hall at the 50-GeV Proton Synchrotron (PS) of J-PARC, the secondary beam line K1.8 with double stage separator is expected to provide 1-2 GeV/c kaon beams with less contamination of pions mainly for hadron and nuclear physics experiments with strangeness. An electrostatic (ES) separator is one of key elements of this secondary beam line. The ES separator will generate a 75kV/cm electrostatic field between parallel electrodes of 10cm gap and 6m in length along the beam direction. It is designed so as to be radiation-proof and to lower spark rate at the high intensity proton accelerator facility. The K1.8 line has two 6m ES separators with the intermediate focal point upstream of separators to reduce the pion backgrounds from the production target. The K-/π- ratio of the line is expected to have a larger value than 1 at the experimental target. Beam commissioning of the K1.8 has just started. We will report separator performance, optics design of the K1.8 beam line and the first result of the beam commissioning.
CERN, Geneva
IN2P3 IPNL, Villeurbanne
INFN/LNL, Legnaro (PD)
Istituto Nazionale di Fisica Nucleare, Milano
The CNGS facility (CERN Neutrinos to Gran Sasso) aims at directly detecting muon to tau neutrino oscillations. An intense muon-neutrino beam (1017 muon neutrinos/day) is generated at CERN and directed over 732km towards the Gran Sasso National Laboratory, LNGS, in Italy, where two large and complex detectors, OPERA and ICARUS, are located. CNGS is the first long-baseline neutrino facility in which the measurement of the oscillation parameters is performed by observation of the tau-neutrino appearance. The facility is approved for a physics program of five years with a total of 22.5·1019 protons on target. Having resolved successfully some initial issues that occurred since its commissioning in 2006, the facility had its first complete year of physics in 2008. By the end of the 2009 physics run the facility will have delivered in total more than 5·1019 protons on target corresponding to ~2-3 tau neutrino events in the OPERA detector. The experiences gained in operating this 500 kW neutrino beam facility along with highlights of the beam performance in 2008 and 2009 are discussed.
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.
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.
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.
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.
PSI, Villigen
A simulation based optimization of a collimator system at the 590 MeV PSI proton accelerator is presented, for the ongoing beam power upgrade from the current 1.2 MW [2 mA] towards 1.8 MW [3 mA]. The collimators are located downstream of the 4 cm thick graphite meson production target. These are designed to shape the optimal beam profile for low-loss beam transport to the neutron spallation source SINQ. The optimized collimators are predicted to withstand the beam intensity up to 3 mA, without sacrificing intended functionalities. The collimator system is under the heavy thermal load generated by a proton beam power deposition approximately of 240 kW at 3 mA, and it needs an active water cooling system. Advanced multiphysics simulations are performed for a set of geometric and material parameters, for the thermomechanical optimization of the collimator system. In particular, a FORTRAN subroutine is integrated into CFD-ACE+, for calculating local beam stopping power in the collimator system. Selected results are then compared with those of full MCNPX simulations.
STFC/RAL, Chilton, Didcot, Oxon
University of Warwick, Coventry
STFC/RAL/ISIS, Chilton, Didcot, Oxon
Sheffield University, Sheffield
STFC/RAL/ASTeC, Chilton, Didcot, Oxon
The UK programme of high power target developments for a Neutrino Factory is centred on the study of high-Z materials (tungsten, tantalum). A description of lifetime shock tests on candidate materials is given as part of the research into a solid target solution. A fast high current pulse is applied to a thin wire of the sample material and the lifetime measured from the number of pulses before failure. These measurements are made at temperatures up to ~2000 K. The stress on the wire is calculated using the LS-DYNA code and compared to the stress expected in the real Neutrino Factory target. It has been found that tantalum is too weak to sustain prolonged stress at these temperatures but a tungsten wire has reached over 26 million pulses (equivalent to more than ten years of operation at the Neutrino Factory). An account is given of the optimisation of secondary pion production from the target and the issues related to mounting the target in the muon capture solenoid and target station are discussed.
Sheffield University, Sheffield
University of Warwick, Coventry
STFC/RAL/ISIS, Chilton, Didcot, Oxon
STFC/RAL, Chilton, Didcot, Oxon
Recently reported results on the tungsten lifetime/fatigue tests under conditions expected in the Neutrino Factory target have strengthened the case of solid target option for a Neutrino Factory. This paper gives description of the detailed measurements of the tungsten properties at high temperature and high stress. We have performed extensive set of measurements of the surface displacement and velocity of the tungsten wires that were stressed by passing a fast, high current pulse through a thin sample. Radial and longitudinal oscillations of the wire were measured by a Laser Doppler Vibrometer. The wire was operated at temperatures of 300-2500 K by adjusting the pulse repetition rate. In doing so we have tried to simulate the conditions (high stress and temperature) expected at the Neutrino Factory. Most important result of this study is an experimental confirmation that strength of tungsten remains high at high temperature and high stress. The experimental results have been found to agree very well with LS-DYNA modelling results.
UCLA, Los Angeles, California
BNL, Upton, Long Island, New York
A study of a pion production and capture system for a 4MW target station for a neutrino factory or muon collider is presented. Using the MARS code, we simulate the pion production produced by the interaction of a free liquid mercury jet with an intense proton beam. We study the variation of meson production with the direction of the proton beam relative to the target. We also examine the influence on the meson production by the focusing of the proton beam. The energy deposition in the capture system is determined and the shielding required in order to avoid radiation damage is discussed.
TRIUMF, Vancouver
DAE/VECC, Calcutta
In July 2009 TRIUMF, in collaboration with the University of Victoria and other partners, was awarded Canadian federal government funds for the construction of an electron linear accelerator (e-linac) in support of its expanding rare isotope beam (RIB) program. The project anticipates Provincial funds for the construction of buildings to be announced in June 2010. TRIUMF has embarked on the detailed design for the 10 MeV Injector cryomodule and the first of two 20 MeV Accelerator cryomodules (ACMs), all rated up to 10 mA. The project first stage, ICM and ACM1, providing 25 MeV 4 mA is planned to be completed in November 2013. The injector is being fast tracked in a collaboration with the VECC in Kolkata, India. This paper gives an overview of the facility layout, and accelerator design progress including beam dynamics and cryomodule concept.
KEK, Ibaraki
The KEK injector linac sequentially provides beams, and transfers them to the following four storage rings: a KEKB low-energy ring (LER) (3.5 GeV/positron), a KEKB high-energy ring (HER) (8 GeV/electron), a Photon Factory ring (PF ring; 2.5 GeV/electron), and an Advanced Ring for Pulse X-rays (PF-AR; 3 GeV/electron). So far, beam injection to the PF ring and PF-AR is carried out twice a day, whereas the KEKB rings are operated in the continuous injection mode (CIM) so that the stored current remains almost constant. The KEK linac upgrade project has been started since 2004 so that the PF top-up and KEKB CIM can be performed at the same time. The aim of this upgrade is to change the linac parameters up to 50 Hz, which is the maximum linac beam repetition rate, by using a multi-energy-linac scheme. This upgrade has been successfully completed. The simultaneous top-up operation for three rings has stably been carried out since this April. We will report the simultaneous top-up injection for the KEKB and PF rings in detail.
KEK, Ibaraki
The next generation B-factory 'SuperKEKB' project whose target luminosity is 8 ×1035 cm-2s-1 is under consideration. A 'nano-beam scheme' is introduced to the SuperKEKB. In the scheme, an electron beam (Energy = 7 GeV, Charge = 3-4 nC/bunch, Vertical emittance =2.8 x 10-5 m) and a positron beam (Energy = 4 GeV, Charge = 4 nC/bunch, Vertical emittance = 1.6 x 10-5 m), are required at the end of injector linac. They are quite challenging targets for the present linac. In order to meet the requirements, we will introduce some new components to the linac. They are a photo-cathode RF gun for an electron beam, a positron capture section using new L-band cavities, a newly designed positron-generation target system and a damping ring for a positron beam. This presentation shows a strategy of our injector upgrade.
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.
National University of Defense Technology, Changsha, Hunan
Laser Fusion Research Center, China Academy of Engineering Physics, Mianyang
Center for Optical Research and Education, Utsunomiya University, Utsunomiya
National University of Defense Technology, Graduate School, Changsha
National University of Defense Technology, Parallel and Distributed Processing, Changsha
Ruhr-Universität Bochum, Bochum
We have proposed a scheme for the generation of collimated proton beams from the interaction of an ultra-intense laser pulse with a rear hole target, which is studied by a 2.5D particle-in-cell (PIC) code PLASIM. When an ultraintense short laser pulse irradiates on such a target, the hot electrons will expand fast into the hole from the inner surfaces of the hole, and strong longitudinal sheath electric field and transverse electric field are produced. However, the plasma in the corners expand slower and be compressed strongly, and then a strong plasma jet is sprayed out from the corner with very high speed, which is just like what happened in armor piercing bullet due to the cumulative energy effect. The two jets extend into the hole and focus along the axis of the hole. At last, a high quality collimated proton beam can be obtained near the end of the hole along the propagation axis. It's found that the beam can propagate over a much longer distance without divergence. The effect of the hole diameter on the collimated proton beam is also investigated. Such target may serve as an important source for collimated proton beam in practical applications.
Center for Optical Research and Education, Utsunomiya University, Utsunomiya
Laser Fusion Research Center, China Academy of Engineering Physics, Mianyang
National University of Defense Technology, Graduate School, Changsha
Shanghai Jiao Tong University, Shanghai
National University of Defense Technology, Changsha, Hunan
Ruhr-Universität Bochum, Bochum
National University of Defense Technology, Parallel and Distributed Processing, Changsha
Energetic protons of tens MeV or more produced by intense lasers have been observed in recent experiments and numerical simulations. Meanwhile, significant efforts have been made to improve the proton beam quality *,**,***. For most applications, it is important to improve the quality of the proton beam both during the production and during the propagation. Some schemes are proposed to improve the quality of the proton beam both during the production form the laser plasma interaction and during the propagation. The physics is investigated by 2D3V and 3D particle-in-cell codes PLASIM and PLASIM3D. In this paper, we propose to use an umbrella-like target to accelerate, and collimate protons. It is found that high intensity collimated MeV-proton beams can be produced ****. We also propose a scheme to generate quasi-monoenergetic proton beam from the interactions of an ultra-intense laser pulse and a thin tailored hole target. Particle simulation shows that a monoenergetic proton beam is generated from the hole. The propagation of a proton beam both in vacuum and in a plasma is also studied. Compared with the propagation in vacuum, the proton beam quality can be improved obviously.
* T. Toncian, et al. Science 312, 410(2006).
** B. M. Hegelich, et al. Nature 439, 441(2006).
*** H. Schwoerer, et al. Nature 439, 445(2006).
**** Y. Y. Ma et al., Phys Plasmas 16, 34502(2009).
Muons, Inc, Batavia
Fermilab, Batavia
The designs of accelerator systems that will be needed to transform Fermilab's Project X into a high-power proton driver for a muon collider and/or a neutrino factory are discussed. These applications require several megawatts of beam power delivered in tens or hundreds of short multi-GeV bunches per second, respectively. Project X may require a linac extension to higher energy for this purpose. Other major subsystems that are likely to be needed include storage rings to accumulate and shorten the proton bunches and an external beam combiner to deliver multiple bunches simultaneously to the pion production target.
KURRI, Osaka
Until today, scaling FFAG accelerator were only designed in a ring shape. But a new criteria of the magnetic field configuration satisfying the scaling condition even for straight FFAG beam line has been recently found. Moreover, combining different types of cells can be used to imagine new lattices. Various applications using these recent developments are here examined: inprovements of the PRISM project and the ERIT project, and a zero-chromatic carbon gantry concept are presented.
CLASSE, Ithaca, New York
We are developing techniques for measuring and correcting emittance diluting optical and alignment errors in the CesrTA storage ring. Our principle measurement method is to resonantly excite the beam at all three normal mode frequencies and then to extract the amplitude and phase of each mode at all 100 beam position monitors. We reconstruct beta-functions, betatron phase advance, coupling parameters, dispersion, and BPM tilts from the data. A complete characterization including data collection and analysis can be done in a few minutes. To measure the emittance, an x-ray beam size monitor capable of measuring the size of a single bunch on a turn by turn basis provides a real time measure with a resolution on the order of a few microns. This resolution corresponds to a few pm emittance. Our ability to identify alignment and optical errors is limited by systematic measurement errors. We report on the status of our efforts to understand and eliminate systematic errors, the accuracy of our characterization of the machine optics, and our success at reducing sources of emittance dilution.
SLAC, Menlo Park, California
Turn-by-turn beam position monitor (BPM) data from multiple BPMs are fitted with a tracking code to calibrate magnet strengths in similar manner as the well known LOCO code. Simulation shows that this method can be a quick and efficient way for optics calibration. The method is applicable to both linacs and ring accelerators. We also show experimental measurement of the transfer matrix with turn by turn BPM data.
FZJ, Jülich
The High-Energy Storage Ring (HESR) is part of the upcoming Facility for Antiproton and Ion Research (FAIR). The HESR will provide antiprotons in the momentum range from 1.5 to 15 GeV/c for the internal target experiment PANDA. The demanding requirements of PANDA in terms of beam quality and luminosity together with a limited production rate of antiprotons call for a long beam life time and a minimum of beam loss. Thus, a sufficiently large dynamic aperture of the HESR is crucial. To provide this, a chromaticity correction scheme for the HESR has been developed to reduce tune spread and thus to minimize the emittance growth caused by betatron resonances. The chromaticity correction scheme has been optimized through dynamic aperture calculations. The estimated field errors of the HESR dipole and quadrupole magnets have been included in the non-linear beam dynamics studies. The ion optical settings of the HESR have been improved using dynamic aperture calculations and frequency map analysis technique. In this presentation comprehensive beam simulations are presented and predictions of long-term stability based on short-term particle tracking and orbit diffusion discussed.
CERN, Geneva
INFN/LNF, Frascati (Roma)
The wigglers of the DAΦNE main rings have been one of the main sources of the non-linearities in the collider. A method to minimize the odd integrated multipoles around the beam trajectory (the even ones tend to vanish due to the periodicity of the device) is described. It consists in displacing the magnetic axis of each pole towards the position of the beam in such a way that the integrated odd multipoles are minimized in each half period of the wiggler. After a study, including multipolar and tracking analysis, has performed to determine the best position of the axes, the wigglers in the DAΦNE main rings have been modified accordingly. To validate this approach magnetic measurements and tests with beam by means of closed orbit bumps have been performed.
CERN, Geneva
During the design phase of the CERN Large Hadron Collider the dynamic aperture, i.e., the domain in phase space where stable motion occurs, was used as figure-of-merit to specify the field quality of the various classes of superconducting magnets. The programme of magnetic measurements performed within the framework of the magnets' acceptance process has produced a large amount of information available, which can be used to estimate the value of the dynamic aperture for the actual machine. In this paper the results of massive numerical simulations based on the measured field quality, both for injection and top energy configurations, are presented and discussed in detail.
Diamond, Oxfordshire
Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Berlin
JAI, Oxford
CERN, Geneva
The correct implementation of the nonlinear ring model is crucial to achieve the top performance of a synchrotron light source. Several dynamics quantities can be used to compare the real machine with the model and eventually to correct the accelerator. Most of these methods are based on the analysis of turn-by-turn data of excited betatron oscillations. We present the experimental results of the campaign of measurements carried out at the Diamond. A combination of Frequency Map Analysis and resonant driving terms measurements has allowed a precise calibration of the nonlinear model capable of reproducing and then correcting the nonlinear beam dynamics in the storage ring.