LBNL, Berkeley, California
At LBNL in Berkeley, clinical trials were conducted (1975-1992) for treating human cancer using ion beams from the Bevalac and treated about 700 patients with helium-ion and about 300 patients with neon-ion beams.* Clinical trials (1997-2005) at GSI in Darmstadt, Germany used carbon-ion beams to treat about 250 patients. In 1994, NIRS in Chiba, Japan, commissioned its first-in-the-world ion-beam therapy facility, HIMAC, which accelerates ions as heavy as argon nuclei to 800 MeV/nucleon. Following it, several carbon-ion therapy facilities have been, or will be soon, constructed in: Hyogo (2001) and Gunma (2010), Japan; Heidelberg (2009), Marburg (2010) and Kiel (2012), Germany; Pavia (2010), Italy; Lyon (2013), France; Wiener Neustadt (2013), Austria; Shanghai and Lanzhou, China; and Minnesota and California, USA. Technical specifications of these facilities are: ion sources delivering all ion species from proton to carbon, accelerator energy of 430 MeV/n (30-cm range in tissue), beam intensity of about 109 pps (to deliver 1 Gy/min into 1-liter volume), repetition rate of about 0.5 Hz with long spill (for beam scanning), and treatment beam delivery and patient safety systems.
* Castro, JR, "Future research strategy for heavy ion radiotherapy," in Progress in Radio-Oncology (ed. Kogelnik, H.D.), Monduzzi Editore, Italy, 643-648 (1995).
HMI, Berlin
Charite, Berlin
HZB, Berlin
The ion beam laboratory ISL at the Hahn-Meitner-Institute (HMI) Berlin supplied light and heavy ion beams for research and applications in solid state physics, industry, and medicine. Since 1998, eye tumours are treated with 68 MeV protons in collaboration with the University Hospital Benjamin Franklin, now Charité - Campus Benjamin Franklin. In autumn 2004 the board of directors of the HMI decided to close down ISL at the end of 2006. In December 2006, a cooperation contract between the Charité and the HMI was signed to assure the continuity of the eye tumour therapy, at the moment the only facility in Germany. The accelerator operation will be continued with reduced man-power, requiring changes in the set-up of the accelerators. A new, facile injector for protons is foreseen. Increasing the reliability will be a key issue. The last two years of operation of ISL as a full multi-purpose accelerator will be shown and examples of the research work will be demonstrated. The conversion of a multi-ion, variable energy accelerator to a dedicated accelerator for eye tumour therapy will be discussed.
The Helmholtz-Zentrum Berlin für Materialien und Energie has been formed by the merger of the Hahn-Meitner-Institut Berlin and the Berliner Elektronenspeicherring-Gesellschaft für Synchrotronstrahlung
GSI, Darmstadt
INFN/LNF, Frascati (Roma)
CNAO Foundation, Milan
INFN/LNL, Legnaro (PD)
The Centro Nazionale di Adroterapia Oncologica (CNAO) presently under commissioning in Pavia, Italy, will be the first Italian facility for the treatment of deeply seated tumours with proton and carbon ion beams. The CNAO accelerator comprises a 7 MeV/u injector linac and a 400 MeV/u synchrotron. The 216.8 MHz linac is a copy of the linac at the Heidelberg Ion-Beam Therapy Centre (HIT) and consists of a 400 keV/u 4-rod type RFQ and of a 20 MV IH type drift tube linac. In 2004, a collaboration between CNAO and GSI was established for construction and commissioning of the linac. GSI supervised the manufacturing of the linac and of its technical systems, performed copper-plating, assembly, and tuning (together with IAP Frankfurt), and delivered complete beam diagnostics systems. The RFQ was tested at GSI with proton beams together with the BD systems prior to delivery to CNAO. Installation and commissioning in Pavia were performed in collaboration by CNAO, GSI, and INFN. RFQ and thereafter IH linac were successfully commissioned in two steps in 2009, both with (H3)+ and carbon ion beams. The results of the linac commissioning will be reported as well as a comparison to the HIT linac.
Siemens Med, Erlangen
Siemens DK, Jyllinge
FRIB, East Lansing, Michigan
Siemens has earned three contracts to deliver IONTRIS Particle Therapy accelerator systems* to be operated in Marburg and Kiel, both in Germany, and in Shanghai, China. The accelerator part consists of an injector (7 MeV/u protons and light ions) and a compact synchrotron able to accelerate proton beams up to 250 MeV and carbon ions up to 430 MeV/u. These beams can be slowly extracted and delivered to a choice of fixed-angle horizontal, semi-vertical and vertical beam-ports. An overview of the design will be given and the status of the installation and commissioning work for the first two projects will be shown.
*Particle Therapy is a work in progress and requires country-specific regulatory approval prior to clinical use.
HIT, Heidelberg
Since November, 15th 2009 patients are treated with protons and carbon ions at the Heidelberg Ionbeam Therapy Centre (HIT). The facility - two ion sources, an injector linac and a compact synchrotron - is operated in 24/7-mode with high availability. The HIT beam time schedule is discussed along the statistics automatically generated by the control system. Besides the patient treatment in the first horizontal room beam time is also used to develop enhanced treatment software in the second horizontal room as well as for commissioning the gantry place. Additionally, biophysics studies are served at a separate experimental place. In parallel, an upgrade program for the accelerator is under way: at first a test bench for a third ion source, later on dedicated to He beams, will be used to study several ideas to increase the injector performance. Furthermore operation mechanisms are under progress to control directly the synchrotron dipole and quadrupole fields as well as to regulate the spill structure - the aim of both developments is to form a uniform and extremely stable extracted beam with high duty cycle. An overview on this entire accelerator R&D at HIT will be given.
Hitachi, Ltd., Energy and Environmental System Laboratory, Hitachi-shi
A compact and high-proton-yield 2.45 GHz microwave ion source has been developed and tested on an AccSys Model PL-7 linac. The source that has an overall diameter of 115 mm uses permanent magnets and iron yokes. Microwave power was fed to a plasma chamber with a double ridged waveguide via a coaxial cable. A pulsed hydrogen ion beam of 45 mA was extracted from a single 5 mm diameter extraction aperture with a proton fraction of >90 % at 30 keV and a hydrogen gas flow rate of 1 sccm. A 7-MeV proton current out of the linac with the source reached up to 16 mApeak, which exceeds its design value of 15 mApeak. Excellent stability of no more than 1.5 % in both the ion source extraction current and the linac output current was also demonstrated in an 8-hour operation test.
JAEA, Ibaraki-ken
Toshiba, Tokyo
JAEA/Kansai, Kyoto
Kyoto ICR, Uji, Kyoto
NIRS, Chiba-shi
The interaction between the high intensity laser and the solid target produces a strong electrostatic proton acceleration field (1 TV/m) with extraordinary small size, contributing to downsizing of the particle accelerator. The proton beam exhibits significant features. having very small source size(~10 um), short pulse duration (~ps) and very low transverse emittance. However it is a diverging beam (half angle of ~10 deg) with wide energy spread of ~100 %. Because of these peculiar characteristics the proton beam attracts many fields for applications including medical applications. To preserve these peculiar characteristics, which are not possessed by those beams from the conventional accelerators, towards the irradiation points, we need to establish a peculiar beam transport line. As the first step, here we report the demonstration of the proto-type laser-driven proton medical accelerator beam line in which we combine the laser-driven proton source with the beam transport technique already established in the conventional accelerator for the purpose of comparison between the data and the particle transport simulation code, PARMILA*.
*Harunori Takeda, 2005, Parmila LANL (LA-UR-98-4478).
JAEA, Ibaraki-ken
We report the demonstrated irradiation effect of laser-accelerated protons on human cancer cells. In-vitro (living) A549 cells are irradiated with a proton beam having a single bunch duration of 20 ns and a beam flux of ~1014cm−2s−1*. The dynamics differ by seven orders of magnitude to the case of a typical Ion Beam Therapy (IBT) operation with a synchrotron: 0.4 s in bunch duration and ~107cm−2s−1 in beam flux. We have measured the yield of DNA double-strand break with phosphorylated histone H2AX immunostaining method and estimated Relative Biological Effectiveness (RBE) of the laser-accelerated protons.
* A. Yogo et al., Appl. Phys. Lett. 94, 181502 (2009).
JAEA, Kyoto
KEK, Ibaraki
RIST, Ibaraki
The concept of a compact ion particle accelerator has become attractive in view of recent progress in laser-driven hadrons acceleration. The Photo Medical Research Centre (PMRC) of JAEA was established to address the challenge of laser-driven ion accelerator development for hadrons therapeutic. In the development of the instrument, it is necessary to do the bench-mark of the amount of the different types of radiation by the simulation code for shielding. The Monte Carlo Particle and Heavy Ion Transport code (PHITS) was used for bench-mark the dose on laser-shot radiations of short duration. The code predicts reasonably well the observed total dose as measured with a glass dosimeter in the laser-driven radiations.
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.
CERN, Geneva
EBG MedAustron, Wr. Neustadt
MedAustron is a synchrotron based accelerator facility for cancer treatment in Austria currently in the development phase. The design is based on the PIMMS study* and CNAO** synchrotron. In addition to the clinical application, the accelerator will also provide beams for nonclinical research in the fields of medical radiation physics, radiation biology and experimental physics with an extended proton energy range beyond medical requirements to 800 MeV. The differences to others medical accelerator-based facilities will be elaborated, specifically the used source technologies and configuration (starting up with protons (p) and carbon ions (C6+) allowing a later upgrade to ion species up to neon) and the online verification of all relevant beam parameters. The current project status is presented.
* PIMMS Proton-ion medical machine study, Bryant, Philip J (ed.) et al., CERN, 2000.
** CNAO, www.cnao.it
JAI, Oxford
Imperial College of Science and Technology, Department of Physics, London
UMAN, Manchester
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire
STFC/DL, Daresbury, Warrington, Cheshire
STFC/RAL, Chilton, Didcot, Oxon
Brunel University, Middlesex
STFC/RAL/ASTeC, Chilton, Didcot, Oxon
GIROB, Oxford
Fermilab, Batavia
Gray Institute for Radiation Oncology and Biology, Oxford
Cockcroft Institute, Lancaster University, Lancaster
The status of PAMELA (Particle Accelerator for MEdicaL Applications) ' an accelerator for proton and light ion therapy using a non-scaling FFAG (ns-FFAG) accelerator ' is reviewed and discussed.
JAI, Oxford
STFC/RAL/ASTeC, Chilton, Didcot, Oxon
PAMELA (Particle Accelerator for MEdicaL Applications) employs novel non-scaling Fixed Field Alternating Gradient (NS-FFAG) technology in the development of a proton and C6+ particle therapy facility. One of the challenges of this design is the acceleration of high energy C6+ in a lattice which enables high flexibility and reliability for treatments, yet remains minimal in size and complexity. Discussed here is the Carbon 6+ lattice solution in terms of both design and performance.
JAI, Oxford
Accelerator physics is often viewed as a difficult subject to communicate to schools and the public. The "Accelerate!" project, initiated in the UK in 2008, engages audiences with accelerator physics through a 45-minute live, interactive demonstration show, using basic physics demonstrations to explain the physics of particle accelerators and what they are used for. Feedback has been overwhelmingly positive from all areas, and demand for the show is very high, with over 3000 students involved in the first year of running. The program is also contributing to the science communication skills of physics graduate students. I discuss how to portray basic accelerator concepts through easy to access demonstrations and initial results of audience evaluation of the show.
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.
BNL, Upton, Long Island, New York
There is a dramatic increase in number of proton/carbon cancer therapy facilities in recent years due to their clear advantage over other radiation therapy treatments. The cost of ion cancer therapy is still prohibitive for most of the hospitals, and the dominant costs are beam delivery systems. We previously presented designs of carbon and proton isocentric gantries using non-scaling alternating gradient fixed field magnets (NS-FFAG) *, where gantry magnet size and weight are dramatically reduced. The weight of the transport elements of our NS-FFAG carbon isocentric gantry is 1.5 tons compared to 130 ton gantries recently constructed Heidelberg C facility at Heidelberg. We have also designed a proton NS-FFAG permanent magnet gantry with an estimated weight of 500 kg. We present an update on these designs.
* D. Trbojevic, B. Parker, E. Keil, and A. M. Sessler,
"Carbon/proton therapy: A novel gantry design," PHYSICAL REVIEW SPEC.
TOP. - ACCELERATORS AND BEAMS 10, 053503 (2007).
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
A Superconducting RF (SRF) Linac can be used for an accelerator-driven subcritical (ADS) nuclear power station to produce more than 5 GW electrical power in an inherently safe region below criticality, generating no greenhouse gases, producing minimal nuclear waste and no byproducts that are useful to rogue nations or terrorists, incinerating waste from conventional nuclear reactors, and efficiently using abundant thorium fuel that does not need enrichment. First, the feasibility of the accelerator technology must be demonstrated. We describe the Linac parameters that can enable this vision of an almost inexhaustible source of power and we discuss how the corresponding reactor technology can be matched to these parameters.
KEK, Ibaraki
TIT, Tokyo
Japan Proton Accelerator Research Complex (J-PARC) requires thick carbon stripper foils (200-500 ug/cm2) to strip electrons from the H- beam supplied by the linac before injection into the Rapid Cyclic Synchrotron. A H- beam of 181MeV energy is injected into the 3 GeV Rapid Cycling Synchrotron (RCS) with a pulse length of 0.5 ms, a repetition rate of 25 Hz, and an average beam current of 200 μA. The H- ions are stripped into protons by a charge stripper foil in the injection section. For this high-energy and high-intensity beam, the conventional carbon stripper foils will be ruptured in a very short time. Thus, long-lived thick carbon stripper foils are needed to this high-power accelerator. For this purpose, we are described R and D of long-lived Hybrid Boron-mixed Carbon foils (HBC-foils) of 100 - 500 μg/cm2 by arc discharge method. The preparation procedure is described and lifetime measurement by using a 3.2MeV Ne+ DC beam of 2-3 μA are reported.
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.
KAERI, Daejon
We made an experiment apparatus for the investigation of nano particle synthesis by proton inducing. It is composed of water tank, thin sample case with large area, ultrasonic oscillator, beam entrance window, monitoring camera, etc. Pt nano particles were fabricated. Nano particle characteristics are influenced by the condition of the solution, such as concentrations of H2PtCl6, CP and IPA. The experiment apparatus was designed that Pt nano particles were fabricated fore conditions. For a proton induced synthesis, some parameters, such as beam energy, beam current, flux, total dose, dose rate, etc. are also known as important process variables. To identify the effects of these irradiation parameters, we investigated the properties of nano particles according to the changes of these parameters. The energy was changed in the range of 10 ~ 40 MeV, beam current 1 uA. It could be examined by using an experiment apparatus developed for this purpose.
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.
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.
KEK, Ibaraki
The J-PARC is a high intensity proton accelerator complex, which consists of a LINAC, a Rapid Cycling Synchrotron (RCS) and a Main Ring (MR). The MR injection system employs a high-field septum to deflect the incoming beam from the RCS, which has been used for the beam commissioning study with low beam intensity successfully. Relative large beam losses in the injection area have been observed, which is proportional to the injection beam intensity. In future, the beam intensity will increase about 100 times to realize high beam power (~MW) operation required from neutrino experiments. The beam loss at the injection region is expected increase greatly due to the space charge effects, which creates severe radiation problems. Since the present injection septum coil is organic insulated, which will be destroyed under such a severe irradiation quickly. To cope with this problem, a new high radiation resistant injection septum magnet is developed, which uses inorganic insulation material (Mineral Insulated Cable - MIC) to prevent the septum from radiation damage. This paper investigates different effects caused by the MIC and gives an optimization design.
Kyoto ICR, Uji, Kyoto
A compact neutron source using Li(p,n) or Be(p,n) reaction is proposed. The proton linac consists of ECR ion source, LEBT(Low Energy Beam Transport), RFQ linac and post accelerator. We assume that energy of the proton beam is 3MeV and its peak current is 40 mA operated at the repetition rate is 25Hz with the pulse width of 1ms. The beam from the ion source should be matched to the RFQ, where solenoid coils can handle the large current beam in this LEBT section. To reduce energy consumption in LEBT we're trying to design the Hybrid Electromagnet that consists of solenoid coils and permanent magnets. We use PANDIRA, TRACE-2D, and PBGUNS computer codes in order to simulate the magnetic field and the beam transport through LEBT. In this paper the design of this magnet and the result of its beam matching based on simulation will be presented.
GSI, Darmstadt
IKP, Mainz
BNL, Upton, Long Island, New York
The Electron Nucleon Collider, proposed as an extension to the High Energy Storage Ring (HESR), is currently investigated and a first layout of the Interaction Region (IR) proposed. The limited size of the machine, the low beam energy and the Lorentz force vector pointing in the same direction for both beams make the IR design demanding. In this paper we present the parameters of the IR magnets, show the boundary conditions given by the beam dynamics and the experiments. We present first 2D designs for the electron and proton triplet magnets along with the separating dipole next to the collision point. Different methods to shield the beam in the spectrometer dipoles are investigated and presented.
KEK, Ibaraki
Kyoto University, Kyoto
University of Tokyo, Tokyo
A superconducting magnet system for the J-PARC neutrino beam line was completed at the end of 2008. The system consists of 14 doublet cryostats; each contains 2 combined function magnets (SCFM). The SCFM uses two single layer left/right asymmetric coils that produce a dipole field of 2.6 T and quadrupole of 19 T/m. By 2008, the world first SCFM had been developed and tested successfully at KEK. The mass-production was started in 2005, and completed by summer 2008. The system installation and commissioning took place from Feb. 2008 to Mar. 2009. The beam operation was started in April 2009 and the first neutrino beam was generated on April 23rd. Since then beam operation and commissioning to increase beam intensity has been performed to achieve the near term milestone of 100 kW beam operation. The paper briefly summarizes the history of SCFM development and the system construction as an introduction to a discussion on beam operation experience of the SCFM system.
RCNP, Osaka
KT Science Ltd., Akashi
NIRS, Chiba-shi
CYRIC, Sendai
A scanning magnet using high-temperature superconductor (HTS) wire was designed, fabricated, and tested for its suitability as beam scanner. After successful cooling tests, the magnet performance was studied using DC and AC currents. With DC current the magnet was successfully operated to generate designed field distributions and effective length. In AC mode, the magnet was operated at frequencies of 30-59 Hz and a temperature of 77 K as well as 10-20 Hz and 20K. The power loss dissipated in the coils was measured and compared with the model calculations. The observed loss per cycle was independent of the frequency and the scaling law of the excitation current was consistent with theoretical predictions for hysteretic losses in HTS wires.
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.
UNIDO, Dortmund
CERN, Geneva
IHEP Protvino, Protvino, Moscow Region
We consider the formation of machine background induced by proton losses in the long straight section of the LHCb experiment at LHC. Both sources showering from the tertiary collimators located in the LHCb insertion region as well as local beam-gas interaction are taken into account. We present the procedure for, and results of, numerical studies of such background for various conditions. The expected impact on the experiment and signal characteristics are also discussed.
CERN, Geneva
SLAC, Menlo Park, California
Fermilab, Batavia
Unbunched beam is a potentially serious issue in the LHC as it may quench the superconducting magnets during a beam abort. Unbunched particles, either not captured by the RF system at injection or leaking out of the RF bucket, will be removed by using the existing damper kickers to excite resonantly the particles in the abort gap. Following beam simulations, a strategy for cleaning the abort gap at different energies was proposed. The plans for the commissioning of the beam abort gap cleaning are described, and the first results from the beam commissioning are presented.
BNL, Upton, Long Island, New York
CERN, Geneva
Using the vernier scan or Van der Meer scan technique, where one beam is swept stepwise across the other while measuring the collision rate as a function of beam displacement, the transverse beam profiles, the luminosity and the effective cross section of the detector in question can be measured. This report briefly recalls the vernier scan method and presents results from the first RHIC polarized proton run at 250 GeV/beam in 2009.
CERN, Geneva
National Technical University of Athens, Athens
We study the interaction of macro-particles residing inside the LHC vacuum chamber, e.g. soot or thermal-insulation fragments, with the circulating LHC proton beam. The coupled equations governing the motion and charging rate of metallic or dielectric micron-size macro-particles are solved numerically to determine the time spent by such "dust" particles close to the path of the beam as well as the resulting proton-beam losses, which could lead to a quench of superconducting magnets and, thereby, to a premature beam abort.
BNL, Upton, Long Island, New York
Long range beam-beam experiments were conducted during the Run 2009 in the yellow and the blue beams of the RHIC accelerator with DC wires. The effects of a long-range interaction with a DC wire on colliding and non-colliding bunches with the aid of orbits, tunes, and losses were studied. Results from distance and currents scans and an attempt to compensate a long-range interaction with a DC wire is presented.
BNL, Upton, Long Island, New York
In polarized proton operation the luminosity of RHIC is limited by the head-on beam-beam effect, and methods that mitigate the effect will result in higher peak and average luminosities. Two electron lenses, one for each ring, are being constructed to partially compensate the head-on beam-beam effect in the two rings. An electron lens consists of a low energy electron beam that creates the same amplitude dependent transverse kick as the proton beam. We discuss design consideration, present the main parameters, and estimate the performance gains.
BNL, Upton, Long Island, New York
Precision measurement and control of the betatron tunes and betatron coupling in the Relativistic Heavy Ion Collider (RHIC) are required for establishing and maintaining both good operating conditions and, particularly during the ramp to high beam energies, high proton beam polarization. While the proof-of-principle for simultaneous tune and coupling feedback was successfully demonstrated earlier, routine application of these systems has only become possible recently. Following numerous modifications for improved measurement resolution and feedback control, the time required to establish full-energy beams with the betatron tunes and coupling regulated by feedback was reduced from several weeks to a few hours. A summary of these improvements, select measurements benefitting from the improved resolution and a review of system performance are the subject of this report.
BNL, Upton, Long Island, New York
In this report we present recent experimental data from the Relativistic Heavy ion Collider (RHIC) illustrating effects resulting from of ~ 10 Hz vibrations of the triplet quadrupole magnets in the interactions regions and evaluate the impact of these vibrations on RHIC collider performance. Measurements revealed modulation of the betatron tunes of appreciable magnitude relative to the beam-beam parameter. Comparison of the discrete frequencies in the spectra of the measured beam positions and betatron tunes confirmed a common source. The tune modulations were shown to result from feed-down in the sextupole magnets in the interaction regions. In addition we show that the distortions to the closed orbit of the two counter-rotating beams produced a modulated crossing angle at the interaction point(s).
BNL, Upton, Long Island, New York
During the second half of Run-9, the Relativistic Heavy Ion Collider (RHIC) provided polarized proton collisions at two interaction points with both longitudinal and vertical spin direction. Despite an increase in the peak luminosity by up to 40%, the average store luminosity did not increase compared to previous runs. We discuss the luminosity limitations and polarization performance during Run-9.
BNL, Upton, Long Island, New York
University of Tuebingen, Tuebingen
Installation of electron lenses for the purpose of head-on beam-beam compensation is foreseen at RHIC. To optimize the relative alignment of the electron lens beam with the circulating proton (or ion) beam, photon detectors will be installed to measure the bremsstrahlung generated by momentum transfer from protons to electrons. We present the detector layout and simulations of the bremsstrahlung signal as function of beam offset and crossing angle.
RCNP, Osaka
An upgrade program of the RCNP cyclotron facility for increase of beam intensity and improvement of beam quality is in progress to meet requirements from research in nuclear physics and industrial applications using secondarily produced particles such as neutrons, muons and radioisotopes. A 2.45 GHz ECR ion source using a set of permanent magnets was developed for high intensity proton beam production. The proton beam intensity more than 0.5 mA at an extraction energy of 15 keV has been obtained with a proton ratio more than 80 %. The quality of the pre-accelerated beam from the K140 injector AVF cyclotron has been improved by a flat-top(FT) acceleration system to enhance the beam transmission to the K400 ring cyclotron. Transversal resonant mode of a dee electrode with a span angle of 180 degrees was investigated to achieve the FT acceleration in the frequency region from 50 to 60 MHz. In this paper, developments for high intensity proton beam acceleration and beam quality improvement using the FT acceleration system of the AVF cyclotron will be mainly presented.
STFC/RAL/ASTeC, Chilton, Didcot, Oxon
JAI, Oxford
A novel nonlinear, nonscaling FFAG ring has been designed for proton and ion acceleration [1]. It can be used for proton and carbon therapy as well as a proton driver for various facilities such as a high intensity neutrino factory. The machine has novel features including variable energy extraction and a high repetition rate of about 1 kHz. Taking as an example the PAMELA proton ring, under study at the John Adams Institute in Oxford, we present results of an error study. A calculation of alignment tolerance is made, in which the effects of translational misalignments of the triplet magnets are included. The effect of misalignments on the dynamic aperture of the machine is investigated.
[1] S. L. Sheehy, K. J. Peach, H. Witte, D. J. Kelliher and S. Machida, Phys. Rev. ST Accel. Beams, 13 (2010) 040101
UMAN, Manchester
Accelerator Driven Subcritical Reactors require a high currents of energetic protons. We compute the limits imposed by space charge, and explore what can be achieved using various proposed FFAG lattices. Limitations due to beam losses and reliability are also discussed
JAI, Oxford
PAMELA (Particle Accelerator for MEdicaL Application) aims to design a particle therapy facility using Non-scaling FFAG (Fixed Field Alternating Gradient) accelerator. In the beam extraction in PAMELA, the biggest challenge is the flexible energy variability, which is desirable for better dose field formation. The feature is a unique feature of PAMELA for a fixed field accelerator. To realize energy variable beam extraction, PAMELA employs vertical extraction using large a aperture kicker magnet. In the paper, the detail of the extraction scheme, hardware specifications are discussed.
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.
KEK/JAEA, Ibaraki-Ken
KEK, Ibaraki
JAEA/J-PARC, Tokai-mura
The Japan Proton Accelerator Complex includes the 3GeV rapid cycling synchrotron (RCS) and the 50GeV main ring synchrotron (MR). Both synchrotrons use the high field gradient magnetic alloy (MA) loaded cavities. In RCS, 11 RF systems have been fully operational since December 2008. The RCS RF systems are operated with dual-harmonic acceleration voltages. Beam acceleration and bunch shape manipulation are efficiently taking place. 120kW of the neutron user operation was started at the Material and Life science facilities in November 2009. In MR synchrotron, the 5th RF system were installed in August 2009, and therefore 5 RF systems are now in operation. Beam commissioning for delivering protons to the hadron facility and neutrino beam experimental facility are under way. The neutrino user experiment is intended to start January 2010. Proton beam operation with more than 100kW is required. The approaches to realizing high intensity operation and the MR upgrade plan will be presented.
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.
JINR, Dubna, Moscow Region
Fermilab, Batavia
FZJ, Jülich
Main element of the NICA facility is the collider equipped with stochastic and electron cooling systems to provide experiment with heavy ions like Au, Pb or U at energy from 1 to 4.5 GeV/u with average luminosity of the level of 1027 cm-2 s-1. The possible lattices providing the required parameters are discussed.
JINR, Dubna, Moscow Region
JINR/LHE, Moscow
The Nuclotron-based Ion Collider fAcility (NICA) is the new accelerator complex being constructed at JINR aimed to provide collider experiments with heavy ions up to uranium at the center of mass energy from 4 to 11 GeV/u. It includes 6 Mev/u linac, 600 MeV/u booster, upgraded SC synchrotron Nuclotron and collider consisting of two SC rings, which provide average luminosity of the level of 1027cm-2s-1.
Siemens AG, Healthcare Technology and Concepts, Erlangen
Air insulated Cockcroft-Walton (Grienacher) cascades have been historically used to generate high voltages for accelerating particles. This paper explores how this technology can be utilised through a system level approach to develop more compact accelerator configurations with much higher voltages and gradients. One such concept is presented that realises a 20MeV, 1mA tandem accelerator that has a footprint ~2m^2
WERC, Tsuruga , Fukui
We have operated the accelerator system which consists of a tandem accelerator and a synchrotron since the completion of the construction and beam commissioning at the Wakasa-wan Energy Research Center, Tsuruga, Japan in 2000. The acceleration voltage of the tandem accelerator amounts to 5 MV and is generated by the Dynamitron-type cascade voltage doubler rectifier. The beam from the tandem accelerator is transported to the MeV-ion experimental area for the irradiation to the industrial or biological material and for the ion beam analysis. The tandem beam is also injected to the 200 MeV proton synchrotron. The synchrotron beam has been used for the high energy irradiation and the cancer therapy. The tandem accelerator is used for a lot of purposes including cancer therapy, therefore, stable operation of the system and efficient sharing of the operation duration are required. Developments of the accelerator are presented putting a stress on the stable and efficient operation of the system in this paper.
Cockcroft Institute, Warrington, Cheshire
INFN/LNS, Catania
The University of Liverpool, Liverpool
Future atomic and nuclear physics experiments put challenging demands on the required beam instrumentation. Low energy (<1 MeV), low intensity (<107 pps) beams will require highly sensitive monitors. This is especially true for the Facility for Low-energy Antiproton and Ion Research (FLAIR) where antiproton beams will be decelerated down to 20 keV and as few as 5·105 particles per second will be slowly extracted for external experiments. In order to investigate the limits of scintillating screens for beam profile monitoring in the low energy, low intensity regime a structured analysis of several screen materials, including CsI:Tl, YAG:Ce and scintillating fibre optic plate (SFOP), has been done under different irradiation conditions with keV proton beams. This contribution will present the experimental setup and summarize the results of this study.
IAP, Frankfurt am Main
GSI, Darmstadt
For the research program with cooled antiprotons at FAIR a dedicated 70 MeV, 70 mA proton injector is required. The main acceleration of this room temperature linac will be provided by six coupled CH-cavities operated at 325 MHz. Each cavity will be powered by a 3 MW klystron. For the second acceleration unit from 11.7 to 24.3 MeV a 1:2 scaled model has been built. Low level RF measurements have been performed to determine the main parameters and to prove the concept of coupled CH-cavities. For this second tank technical and mechanical investigations have been done in 2009 to prepare a complete technical concept for manufacturing. Recently, the construction of the prototype has started. The main components of this second cavity will be ready for measurements in spring 2010. At that time the cavity will be tested with dummy stems (made from aluminum) wich will allow precise frequency and field tuning. This paper reports on the technical development and achievements during the last year. It will outline the main fabrication steps towards that novel type of proton DTL.
KEK, Ibaraki
JAEA/J-PARC, Tokai-mura
JAEA, Ibaraki-ken
The user operation of J-PARC linac was started in December 2008, and it has been operated with the limited beam power of less than 1.2 kW making efforts at improving hardware availability. Since November 2007, the beam power from the linac has been increased to 7.2 kW that corresponds to 120 kW from the downstream 3-GeV synchrotron. We also performed a high-power demonstration run with 18 kW (or 300 kW from the synchrotron) that corresponds to the design beam power for the present configuration. In the course of the beam power ramp-up, we have suffered from significant beam losses in the beam transport line after the linac. Accordingly, the emphasis of the beam tuning has been shifted to the mitigation of the uncontrolled beam losses. Some of the loss mechanisms are identified in the beam studies, and we have succeeded in mitigating them. In this paper, we present recent progress in the beam commissioning of J-PARC linac with emphasis on the effort to mitigate the beam losses.
TUB, Beijing
TechSource, Santa Fe, New Mexico
NUCTECH, Beijing
The design progress of the Radio Frequency Quadrupole (RFQ) accelerator for the Compact Pulsed Hadron Source (CPHS) at Tsinghua University is presented in this paper. The RFQ will accelerate protons from 50 keV to 3 MeV, with the RF frequency of 325 MHz. The objective is to obtain the optimum structure of the RFQ accelerator with high transmission rate and tolerable total length. The beam dynamics are studied by the simulation of the proton beam in the RFQ accelerator with the code of PARMTEQM. The output proton beam from the RFQ is well matched into the DTL without Medium-Energy-Beam-Transport (MEBT) between the RFQ and DTL.
* K.R. Crandall et al., RFQ Design Codes, LA-UR-96-1836.
TUB, Beijing
TechSource, Santa Fe, New Mexico
NUCTECH, Beijing
CIAE, Beijing
CERN, Geneva
IHEP Beijing, Beijing
The Compact Pulsed Hadron Source (CPHS) has launched at Tsinghua University to develop a university neutron source based on a 13 MeV, 50 mA proton linac which consists of ECR ion source, LEBT, RFQ and DTL. The primary design of the DTL for the CPHS is presented in this paper, which includes the dynamics calculation, RF field optimization and error analysis. This DTL can accelerate 50 mA proton beam from 3MeV to 13 MeV with 1.2 MW RF power input. The DTL is directly connected after RFQ without Medium-Energy Beam-Transport line (MEBT). PMQs are adopted in drift tubes focusing. The magnetic field gradient of PMQs are programmed to match the transverse restoring forces at the end of the RFQ to avoid missmatch and avoid parametric resonances.
Imperial College of Science and Technology, Department of Physics, London
JAI, Egham, Surrey
The PAMELA (Particle Accelerator for MEdicaL Applications) project aims to design an ns-FFAG accelerator for cancer therapy using protons and carbon ions. For the injection system for carbon ions, an RFQ is one option for the first stage of acceleration. Our integrated RFQ design process* has been developed further using Comsol Multiphysics for electric field modelling. The design parameters for the RFQ are automatically converted to a CAD model using Autodesk Inventor, and the electric field map for this model is simulated in Comsol. Particles can then be tracked through this field map using Pulsar Physics' General Particle Tracer (GPT). Our software uses Visual Basic for Applications and MATLAB to automate this process and allow for optimisation of the RFQ design parameters based on particle dynamical considerations. Possible designs for the PAMELA RFQ, including super-conducting and normal-conducting solutions, will be presented and discussed, together with results of the field map simulations and particle tracking for these designs.
* M J Easton et al., RFQ Design Optimisation for PAMELA Injector, PAC09, Vancouver, Canada, April 2009, FR5REP066.
Fermilab, Batavia
University of Delhi, Delhi
650 MHz option for the high energy part of the 2.6 GeV, CW Project X linac is discussed. It may give significant benefits compared to current 1.3 GHz option based on the utilization of ILC-type beta=1 cavities. Results of the break point optimization for linac stages, cavity optimization and beam dynamics optimization are presented. Possible reduction in the number of cryomodules and linac length compared to the current linac project version is discussed. Cryogenic losses are analyzed also.
GSI, Darmstadt
Nagaoka University of Technology, Nagaoka, Niigata
FZJ, Jülich
JINR, Dubna, Moscow Region
Anti-proton beam accumulation at CERN and FNAL has been performed with use of stochastic stacking in the momentum space. Thus accumulated beam has a large momentum spread and resultantly large radial beam size with large dispersion ring. In the present proposed scenario, beams from the pre-cooling ring are injected into the longitudinal empty space prepared by the barrier voltages and subsequently the stochastic cooling is applied. After the well cooling, barrier voltages will prepare again the empty space for the next beam injection. We have simulated the stacking process up to 100 stacking with use of the bunched beam tracking code including the stochastic cooling force and the diffusion force such as Schottky diffusion term, thermal diffusion, IBS effects. The synchrotron motion by barrier voltages are included with 4th order symplectic method. Examples of the application to 3 GeV anti-proton beam for the HESR ring in FAIR project are presented as well as the accumulation of heavy ion beam 3.5 GeV/u Au, at the NICA collider at JINR project.
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.
Kyoto ICR, Uji, Kyoto
NIRS, Chiba-shi
S-LSR is a compact ion storage and cooler ring to inject beam of the 7MeV proton and the 40MeV Mg+. The average vacuum pressure measured by the vacuum gauges without beam was achieved up to about 4x10-9 Pa in 2007. Many experiments have been carried out using the proton and Mg beam, for example the one-dimensional beam ordering of protons utilizing the electron cooler, the extraction tests of the short bunched beam and the laser cooling for the Mg beam had been performed. The beam lifetime can be estimated with the vacuum pressure or the loss-rate of the beam energy. The values of the estimated lifetime are nearly equal to the measured lifetime values. The present status of the proton beam lifetime and the vacuum pressure is reported.
YerPhI, Yerevan
The Vibrating Wire Monitor (VWM) with aperture 20 mm was developed for scan of electron beam with large transversal sizes. Test experiments with VWM placed in air were done on the 20 MeV electron beam of Yerevan Synchrotron Injector with 4-7 uA at outlet. A new design of VWM is proposed for scan of the beam with even greater transversal sizes.
FZJ, Jülich
UniDo/IBS, Dortmund
GSI, Darmstadt
JINR, Dubna, Moscow Region
To study electron cooling in a synchrotron nondestructive methods only are suitable. The ionization profile monitor (IPM) delivers real-time data in both transverse planes allowing detailed analysis of beam profile evolution in COSY. First attempts to use scintillation of residual gas (SPM) to measure beam profiles were very promising. Beam diagnostics based on recombination is usually used to optimize electron cooling of protons (H0-diagnostics). However, it is not available when cooling antiprotons. So the IPM and possibly the SPM are vital for electron cooling optimization in the HESR ring. The new beam instrumentation at COSY is introduced and its relevance for the new 2 MeV electron cooler project and the HESR are discussed. Results of beam studies performed during electron cooling beam times 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.
KEK, Ibaraki
MELCO SC, Tsukuba
J-PARC, KEK & JAEA, Ibaraki-ken
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken
Experiences of operating BPM's during beam commissioning at the J-PARC MR are reported. The subjects are: (1) bug report, statistics and especially the effect of a beam duct step, (2) position resolution estimation (<30 micrometers with 1 sec averaging), (3) beam based alignment.
KEK, Ibaraki
Osaka University, Osaka
Proton beam extinction, defined as a residual to primary ratio of beam intensity, is one of the most important parameters to realize the future muon electron conversion experiment (COMET) proposed at J-PARC. To achieve the required extinction level of 10-9, we started measuring beam extinction at main ring (MR) as the first step. The newly developed beam monitor was installed into the abort beam line and the first measurement was successfully performed by using the fast-extracted MR beam. We found that empty RF buckets of RCS, in which all protons were considered to be swept away by a RF chopper before injection to RCS,, contained about 10-5 of the main beam pulse due to chopper inefficiency. We are now developing a new beam monitor with improved performance for further studies at the abort line. In addition, we have started new measurements at the different stage of proton acceleration, i.e. at Linac, 3-50 BT line, and the main ring. In this paper, we present recent results and future prospect of beam extinction measurements.
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.
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.
KAERI, Daejon
The PEFP (Proton Engineering Frontier Project) is constructing a 100-MeV proton accelerator, consisting of a 50-keV proton injector, LEBT (Low Energy Beam Transport), a 3-MeV RFQ (Radio Frequency Quadrupole), a 20-MeV DTL (Drift Tube Linac), 100-MeV DTL, and beam lines. In order to monitor signals measured from RF components and beam current monitors equipped to the 20-MeV proton accelerator, the commercial digital sampling oscilloscopes (DSO) are used. The signals, which are measured from the DSOs, must be calibrated and transmitted promptly to accelerator operators. So LabView as Window PC-based software, which equipped with various VISA (Virtual Instruments Software Architecture) interface as a standard I/O language for instrumentation programming, was chosen to do this data acquisition. The LabView was built with EPICS middleware by using the Window-based shared memory approach. In this paper, the preliminary design and implementation on integrating EPICS and LabView for the RF and beam current monitor are described.
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.
CERN, Geneva
As part of the CERN LHC injector chain upgrade, LINAC4 will accelerate H- ions from 45 keV to 160 MeV. A movable diagnostics test bench will be used to measure the beam parameters during the different construction stages (at 45 keV, 3 MeV and 12 MeV) at first in a laboratory setup and later in the LINAC4 tunnel. Given the beam properties at 3 and 12 MeV, the existing slit-grid system developed for the measurement of the transverse emittance at the source (45 keV) cannot be reused at these higher energies. At 3MeV and above the energy deposition would damage the steel slit in a single LINAC4 pulse. For this reason a new slit has been designed following detailed analytical and numerical simulations for different materials and geometries. The energy deposition patterns as simulated by FLUKA for the different cases are presented in detail. In addition, the choice of SEM grid wires for achieving the required measurement accuracy in terms of material, diameter and spacing, are discussed.
CERN, Geneva
SMI, Vienna
The hyperfine transition frequency of hydrogen is known to a very high precision and therefore the measurement of this transition frequency in antihydrogen is offering one of the most accurate tests of CPT symmetry. The ASACUSA collaboration will run an experiment designed to produce ground state antihydrogen atoms in a CUSP trap. These antihydrogen atoms will pass with a low rate in the order of 1 per second through a spin-flip cavity where they get excited depending on their polarization by a 1.42 GHz magnetic field. Due to the small amount of antihydrogen atoms that will be available the requirement of good field homogeneity is imposed in order to obtain an interaction with as many antihydrogen atoms as possible. This leads to a requirement of an RF field deviation of less than ± 10 % transverse to the beam direction over a beam aperture with 100 mm diameter. All design aspects of this new spin-flip cavity, including the required field homogeneity and vacuum aspects, are discussed.
CERN, Geneva
SLAC, Menlo Park, California
The University of Liverpool, Liverpool
Synchrotron radiation is currently used on LHC for beam imaging and for monitoring the proton population in the 3 microsecond abort gap. In addition to these existing detectors, a study has been initiated to provide longitudinal density profiles of the LHC beams with a high dynamic range and a 50ps time resolution. This would allow for the precise measurement both of the bunch shape and the number of particles in the bunch tail or drifting into ghost bunches. A solution is proposed based on counting synchrotron light photons with two fast avalanche photo‐diodes (APD) operated in Geiger mode. One is free‐running but heavily attenuated and can be used to measure the core of the bunch. The other is much more sensitive, for the measurement of the bunch tails, but must be gated off during the passage of the core of the bunch to prevent the detector from saturating. An algorithm is then applied to combine the two measurements and correct for the detector dead time, after pulsing and pile‐up effects. Initial results from laboratory testing of this system are described in this paper.
CERN, Geneva
CERN's Large Hadron Collider (LHC) is equipped with three distinct types of intensity measurement systems: total intensity measurement using DC transformers (DCCTs) with a bandwidth up to a few kHz; total intensity measurements on a turn-by-turn basis for lifetime measurements using AC-coupled fast transformers (fast BCTs); bunch-by-bunch intensity measurements with a bandwidth up to a few hundred MHz also using the fast BCTs. In addition to providing intensity information these devices are part of the machine protection system, indicating whether or not there is beam circulating, transmitting intensity for evaluation of safe beam conditions and capable of triggering a beam dump if fast losses are detected. This paper reports on the commissioning of all these systems and their initial performance.
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.
Fermilab, Batavia
UMiss, University, Mississippi
There are conflicting requirements on the value of the momentum compaction factor during energy ramp in a synchrotron: at low energies it should be positive and sufficiently large to make the slippage factor small so that it is possible to work closer to the RF voltage crest and ensure sufficient RF bucket area, whereas at higher energies it should be small or negative to avoid transition crossing. In the present report we propose a lattice with variable momentum compaction factor and consider the possibility of using it in a high repetition rate proton driver for muon collider and neutrino factory.
CERN, Geneva
IHEP Protvino, Protvino, Moscow Region
TRIUMF, Vancouver
The LHC has two dedicated cleaning insertions: IR3 for momentum cleaning and IR7 for betatron cleaning. The collimation system has been specified and built with tight mechanical tolerances (e.g. jaw flatness ~ 40 μm) and is designed to achieve a high accuracy and reproducibility of the jaw positions. The practically achievable cleaning efficiency of the present Phase-I system depends on the precision of the jaw centering around the beam, the accuracy of the gap size and the jaw parallelism against the beam. The reproducibility and stability of the system is important to avoid the frequent repetition of beam based alignment which is currently a lengthy procedure. Within this paper we describe the method used for the beam based alignment of the LHC collimation system, its achieved accuracy and stability and its performance at 450GeV.
ANL, Argonne
Peta-scalable software packages for beam dynamic simulations are being developed and used at the Argonne Leadership Computing Facility. The standard Particle-In-Cell (PIC) method and direct Vlasov solvers in 4 dimensions have been developed and benchmarked with respect to each other. Both of them have been successfully run on 32 thousands processors on BG/P at Argonne National Laboratory. Challenges and prospects of developing Vlasov solvers in higher dimensions will be discussed. Several scalable Poisson solvers have been developed and incorporated with these software packages. Domain decomposition method has been used for the parallelization. In the future developments, these algorithms will be applied to hundreds of thousands processors for peta-scale computing. These software packages have been applied for the design of accelerators, and some large scale simulations will be shown and discussed.
Fermilab, Batavia
As the Fermilab Tevatron Collider program draws to a close, a strategy has emerged of an experimental program built around the high intensity frontier. The centerpiece of this program is a superconducting H- linac that will support world leading programs in long baseline neutrino experimentation and the study of rare processes. Based on technology shared with the International Linear Collider, Project X will provide multi-MW beams at 60-120 GeV from the Main Injector, simultaneous with very high intensity beams at lower energies. Project X also supports development of a Muon Collider as a future facility at the energy frontier.
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.
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.
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.
MEPhI, Moscow
The beam loading effect is one of main problems limiting the beam current. Usually this effect takes into account only in high energy electron linacs. Due to low energy electron and, especially, ion linacs nowadays current increasing the beam loading effect should be considered here. Self consistent beam dynamics simulation methods with Coulomb field and beam loading effect are discussed. The simulation results are in good agreement with experiment which have been carried out on NRNU MEPhI electron linac.
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.
TU Darmstadt, Darmstadt
GSI, Darmstadt
FZJ, Jülich
During the redesign of the low level RF system for the S-DALINAC, a baseband approach was chosen. The RF signals from/ to the cavity are converted into the baseband via I/Q Modulators/ Demodulators. The advantage of this design was realized lateron, as adaption of other frequencies becomes rather easy. The system, originally designed for 3 GHz superconducting cavity in cw operation is currently modified to control a 324 MHz room temperature CH cavity in pulsed operation. We will report on the rf control system principle, the required modifications and first results.
MPI-P, München
IHEP Beijing, Beijing
Simulations of frictional cooling for a muon collider front end scheme show that it is a viable technique for quickly producing colliding beams. The Frictional Cooling Demonstration experiment at the Max Planck Institute for Physics, Munich, aims to demonstrate the working principle of frictional cooling on protons using a 10-cm-long cooling cell. The experiment is nearing the final data taking stages. The status of the experiment is presented along with recent data. Simulation of the experiment setup is also presented.
MPI-P, München
IHEP Beijing, Beijing
Muon colliders would open new frontiers of investigation in high energy particle physics, allowing precision measurements to be made at the TeV energy frontier. One of the greatest challenges to constructing a muon collider is the cooling of a beam of muons on a timescale comparable to the lifetime of the muon. Frictional cooling holds promise for use in a muon collider scheme. By balancing energy loss to a gas with energy gain from an electric field, a beam of muons is brought to an equilibrium energy in 100s of nanoseconds. A frictional cooling scheme for producing high-luminosity beams for a muon collider is presented.
CERN, Geneva
UMAN, Manchester
Cockcroft Institute, Warrington, Cheshire
The University of Liverpool, Liverpool
DESY, Hamburg
DESY Zeuthen, Zeuthen
INFN-Bologna, Bologna
The LHeC aims at colliding hadron-lepton beams with center of mass energies in the TeV scale. For this purpose the existing LHC storage ring is extended by a high energy electron accelerator in the energy range of 60 to 140 GeV. The electron beam will be accelerated and stored in a LEP like storage ring in the LHC tunnel. In this paper we present the layout of the interaction region which has to deliver at the same time well matched beam optics and an efficient separation of the electron and proton beams. In general the large momentum difference of the two colliding beams provides a very elegant way to solve this problem: A focusing scheme that leads to the required beam sizes of the electrons and protons is combined with an early but gentle beam separation to avoid parasitic beam encounters and still keep the synchrotron radiation level in the IR within reasonable limits. We present in this paper two versions of this concept: A high luminosity layout where the mini beta magnets are embedded into the detector design as well as an IR design that is optimised for maximum acceptance of the particle detector.
CERN, Geneva
N.U, Nigde
UMAN, Manchester
Cockcroft Institute, Warrington, Cheshire
Ankara University, Faculty of Sciences, Tandogan/Ankara
The University of Liverpool, Liverpool
UU, Bursa
DESY Zeuthen, Zeuthen
BNL, Upton, Long Island, New York
University of Pisa and INFN, Pisa
INFN-Bologna, Bologna
DESY, Hamburg
SLAC, Menlo Park, California
In a linac-ring electron-proton collider based on the LHC ("LR-LHeC"), the final focusing quadrupoles for the electron beam can be installed far from the collision point, as far away as the proton final triplet (e.g. 23 m) if not further, thanks to the small electron-beam emittance. The inner free space could either be fully donated to the particle-physics detector, or accommodate "slim" dipole magnets providing head-on collisions of electron and proton bunches. We present example layouts for either scenario considering electron beam energies of 60 and 140 GeV, and we discuss the optics for both proton and electron beams, the implied minimum beam-pipe dimensions, possible design parameters of the innermost proton and electron magnets, the corresponding detector acceptance, the synchrotron radiation power and its possible shielding or deflection, constraints from long-range beam-beam interactions as well as from the LHC proton-proton collision points and from the rest of the LHC ring, the passage of the second proton beam, and the minimum beta* for the colliding protons.
GSI, Darmstadt
CERN, Geneva
The presence of an electron cloud in an accelerator generates a number of interesting phenomena. In addition to electron-driven beam instabilities, the electron "pinch" occurring during a beam-bunch passage gives rise to a highly nonlinear force experienced by individual beam particles. A simple 1-dimensional model for the effect of the electron pinch on the beam reveals a surprisingly rich dynamics. We present the model and discuss simulation results.
CERN, Geneva
SLAC, Menlo Park, California
BNL, Upton, Long Island, New York
Cockcroft Institute, Warrington, Cheshire
The University of Liverpool, Liverpool
LPNHE, Paris
We consider three different scenarios for the recirculating electron linear accelerator (RLA) of a linac-ring type electron-proton collider based on the LHC (LHeC): i) a basic version consisting of a 60 GeV pulsed, 1.5 km long linac, ii) a higher luminosity configuration with a 60 GeV 4 km long cw energy-recovery linac (ERL), and iii) a high energy option using a 140 GeV pulsed linac of 4 km active length. This paper describes the footprint, optics of linac and return arcs, emittance growth from chromaticity and synchrotron radiation, a set of parameters, and the performance reach for the three scenarios.
BNL, Upton, Long Island, New York
Beam-beam effects in eRHIC have a number of unique features, which distinguish them from both hadron and lepton colliders. Due to beam-beam interaction, both electron and hadron beams would suffer quality degradation or beam loss from without proper treatments. Those features need novel study and dedicate countermeasures. We study the beam dynamics and resulting luminosity of the characteristics, including mismatch, disruption and pinch effects on electron beam, in additional to their consequences on the opposing beam as a wake field and other incoherent effects of hadron beam. We also carry out countermeasures to prevent beam quality degrade and coherent instability.
Ankara University, Faculty of Sciences, Tandogan/Ankara
CERN, Geneva
In a linac-ring electron-proton collider based on the LHC, before and after the collision point the electron beam can be deflected with weak dipole magnets positioned in front of the superconducting final quadrupole triplets of the 7-TeV proton beam. Significant synchrotron radiation may be produced when the electron beam, of energy 60-140 GeV, passes through these dipole magnets. As an alternative or complement to shielding, parts of the synchrotron radiation could be extracted together with the electron beam. We propose using mirrors with shallow grazing angle to deflect the synchrotron radiation away from the proton magnets. Various LHeC options are considered. Limitations and challenges of this approach are discussed.
BNL, Upton, Long Island, New York
The luminosity of a ring-ring electron-ion collider is limited by the beam-beam effect on the electrons. Simulation studies have shown that for short ion bunches this limit can be significantly increased by head-on beam-beam compensation via an electron lens. However, due to the large beam-beam parameter experienced by the electrons, together with an ion bunch length comparable to the beta-function at the IP, electrons perform a sizeable fraction of a betatron oscillation period inside both the long ion bunches and the electron lens. Recent results of our simulation studies of this effect will be presented.
BNL, Upton, Long Island, New York
IKP, Mainz
FZJ, Jülich
To facilitate studies of collisions between polarized electron and protons at √{s} = 14 GeV constructing an electron-nucleon collider at the FAIR facility has been proposed. This machine would collide the stored 15 GeV polarized proton beam in the HESR with a polarized 3.3 GeV electron beam circulating in an additional storage ring. We describe the interaction region design of this facility, which utilizes the PANDA detector.
KEK, Ibaraki
The carbon stripping foil is the key element for the high-intensity proton accelerator. At KEK, the foil test system using the 650keV H- Cockcroft-Walton accelerator is in operation, which can simulate the energy depositions to the foil with the same amount in the J-PARC. In order to quantatively observe the foil degradations (such as foil thinning, pin-hole production) during irradiation, online energy and particle analyzing system is under construction. This report outlines the design detail of the analyzing system including the detectors.
EBG MedAustron, Wr. Neustadt
CERN, Geneva
The LHC beam dump system has to safely dispose all beams in a wide energy range of 450 GeV to 7 TeV. A 3 μs abort gap in the beam structure for the switch-on of the extraction kicker field ideally allows a loss free extraction under normal operating conditions. However, a low number of asynchronous beam aborts is to be expected from reliability calculations and from the first year's operational experience with the beam dump kickers. For such cases, MAD-X simulations including all optics and alignment errors have been performed to determine loss patterns around the LHC as a function of the position of the main protection elements in interaction region six. Special attention was paid to the beam load on the tungsten collimators which protect the triplets in the LHC experimental insertions, and the tracking results compared with semi-analytical numerical estimates. The simulations are also compared to the results of beam commissioning of these protection devices.
CERN, Geneva
The beam profile screens in the long SPS to LHC transfer lines were used to measure with high precision the emittance growth arising from scattering. The effective thickness of the scatterer could be varied by adding thick Al2O3 fluorescent screens, with the emittance measurement made using very thin Ti OTR screens. The technique allows the intrinsic variation in the emittance from the injector chain to be factored out of the measurement, and was applied to Pb82+ and protons, both with 450 GeV rigidity. The results are presented and the possible applications to the accurate benchmarking of nuclear interaction codes discussed.
CERN, Geneva
The movable LHC injection protection devices in the SPS to LHC transfer lines and downstream of the injection kicker in the LHC were commissioned with low-intensity beam. The different beam-based alignment measurements used to determine the beam centre and size are described, together with the results of measurements of the transverse beam distribution at large amplitude. The system was set up with beam to its nominal settings and the protection level against various failures was determined by measuring the transmission and transverse distribution into the LHC as a function of oscillation amplitude. Beam losses levels for regular operation were also extrapolated. The results are compared with the expected device settings and protection level, and the implications for LHC operation discussed.
CERN, Geneva
We report on first observations and detailed simulations of beam gas rates in the LHC. For the simulations, a comprehensive tool has been set up to simulate in a few hours the expected beam gas losses when pressure maps, collimator settings, and/or beam optics changes. The simulation includes both elastic and inelastic scattering, with subsequent multiturn tracking of proton residues. This provides amongst others a more realistic collimator loss distributions from elastic interactions than what was previously available.
CERN, Geneva
Background and loss rates vary when beams are brought into collisions in the LHC and when the beam separation is varied during luminosity scans. We report on the first observations in the early LHC operation. The observed effects are analyzed and compared with models and simulation.
CERN, Geneva
The UA9 experiment was installed in the CERN-SPS in March '09 in view of investigating crystal assisted collimation in coasting mode. Inside a vacuum vessel, two 2 mm long silicon crystals, bent by about 150 microradians are mounted on accurate goniometers, and a small 10mm long tungsten target is used to compare the effect of crystals with that of a standard scatterer. A moveable 60 cm long block of tungsten is located downstream at about 90 degrees phase advance to intercept the deflected beam. Scintillators, gas GEMs and beam loss monitors measure nuclear loss rates induced by the interaction of the halo beam in the crystal itself. A Roman pot is installed in the path of the deflected particles in between the crystal and the collimator, equipped with a Medipix detector to reconstruct the transverse spot of the impinging beam. Finally UA9 takes advantage of an LHC-collimator prototype installed close to the Roman pot to help in setting the beam conditions and to reveal in a destructive manner the deflected beam shape. This paper describes in details the hardware installed, and the procedures developed to set-up and detect the channeling conditions.
Fermilab, Batavia
CERN, Geneva
UCSD, La Jolla, California
INFN-Ferrara, Ferrara
Magnetically confined hollow electron beams for controlled halo removal in high-energy colliders such as the Tevatron or the LHC may extend traditional collimation systems beyond the intensity limits imposed by tolerable material damage. They may also improve collimation performance by suppressing loss spikes due to beam jitter and by increasing capture efficiency. A hollow electron gun was designed and built. Its performance and stability were measured at the Fermilab test stand. The gun will be installed in one of the existing Tevatron electron lenses for preliminary tests of the hollow-beam collimator concept, addressing critical issues such as alignment and instabilities of the overlapping proton and electron beams.
SLAC, Menlo Park, California
CERN, Geneva
KIT, Karlsruhe
A current issue with the LHC collimation system is single-diffractive, off-energy protons from the primary collimators that pass completely through the secondary collimation system and are absorbed immediately downbeam in the cold magnets of the dispersion suppression section. Simulations suggest that the high impact rate could result in quenching of these magnets. We have studied replacing the 60 cm primary graphite collimators, which remove halo mainly by inelastic strong interactions, with 5.25 mm tungsten, which remove halo mainly by multiple coulomb scattering and thereby reduce the rate of single-diffractive interactions which cause losses in the dispersion suppressor.
UMAN, Manchester
Cockcroft Institute, Warrington, Cheshire
MERLIN is a highly abstracted particle tracking code written in C++ that provides many unique features, and is simple to extend and modify. We have investigated the addition of high order wakefields to this tracking code and their effects on bunches, particularly with regard to collimation systems for both hadron and lepton accelerators. Updates have also been made to increase the code base compatibility with current compilers, and speed enhancements have been made to the code via the addition of multi-threading to allow cluster operation on the grid. In addition, this allows for simulations with large numbers of particles to take place. Instructions for downloading the new code base are given.
CASA, newport news
JLAB, Newport News, Virginia
One key limiting factor to a collider luminosity is bean-beam interactions which usually can cause serious emittance growth of colliding beams and fast reduction of luminosity. Such nonlinear collective beam effect can be a very serious design challenge when the machine parameters are pushed into a new regime. In this paper, we present simulation studies of the beam-beam effect for a medium energy ring-ring electron-ion collider based on CEBAF.
Fermilab, Batavia
CIPS, Boulder, Colorado
Tech-X, Boulder, Colorado
Precision simulations of the electron cloud at the Fermilab Main Injector have been studied using the plasma simulation code VORPAL. Fully 3D and self consistent solutions that includes Yee-type E.M. field maps generated by the cloud and the proton bunches have been obtained, as well detailed distributions of the 6D phase space occupied by the electrons. We plan to include such maps in the ongoing simulation of the space charge effects in the Main Injector. Simulations of the response of retarded field analyzers and microwave transmission experiments are ongoing.
EPFL, Lausanne
CERN, Geneva
Transition crossing in the CERN PS is critical for the stability of high intensity beams, even with the use of a second order gamma jump scheme. The intense single bunch beam used for the neutron Time-of-Flight facility (n-ToF) needs a controlled longitudinal emittance blowup at flat bottom to prevent a fast single-bunch vertical instability from developing near transition. This instability is believed to be of Transverse Mode Coupling (TMCI) type. A series of measurements taken throughout 2008 and 2009 aim at using this TMCI observed on the ToF beam at transition, as a tool for estimating the transverse global impedance of the PS. For this purpose, we compare the measurement results with the predictions of the HEADTAIL code and find the matching parameters. This procedure also allows a better understanding of the different mechanisms involved and can suggest how to improve the gamma jump scheme for a possible intensity upgrade of the n-ToF beam.
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.
Fermilab, Batavia
BNL, Upton, Long Island, New York
In order to avoid the effects of long-range beam-beam interactions which produce beam blow-up and deteriorate beam life time, a compensation scheme with current carrying wires has been proposed. Two long-range beam-beam compensators were installed in RHIC rings in 2006. The effects of the compensators have been experimentally investigated. An indication was observed that the compensators are beneficial to beam life time in measurements performed in RHIC during 2009. In this paper, we report the effects of wire compensator on beam loss and emittance for proton-proton beams at collision energy.
Fermilab, Batavia
Increasing the luminosity requires higher beam intensity and often focusing the beam to smaller sizes at the interaction points. The effects of head-on interactions become even more significant. The head-on interaction introduces a tune spread due to a difference of tune shifts between small and large amplitude particles. A low energy electron beam so called electron lens is expected to improve intensity lifetime and luminosity of the colliding beams by reducing the betatron tune shift and spread. In this paper we discuss the results of beam simulations with the electron lens in RHIC.
Fermilab, Batavia
BINP SB RAS, Novosibirsk
Tevatron electron lenses have been successfully used to mitigate bunch-to-bunch differences caused by long-range beam-beam interactions. For this purpose the electron beam with uniform transverse density distribution was used. Another planned application of the electron lens is the suppression of tune spread due to head-on beam-beam collisions. For this purpose, the transverse distribution of e-beam must be matched to that of the antiproton beam. In 2009, the gaussian profile electron gun was installed in one of the Tevatron electron lenses. We report on the first experiments with non-linear beam-beam compensation. Discussed topics include measurement and control of the betatron tune spread, importance of the beam alignment and stability, and effect of the electron lens on the proton and antiproton beam lifetime.
LBNL, Berkeley, California
CERN, Geneva
One of the options under consideration for a future upgrade of the LHC injector complex includes the replacement of PS with PS2 (a longer circumference and higher energy ring). Efforts are currently underway to design the new machine and characterize the beam dynamics. Electron cloud effects represent a potentially serious limitation to the achievement of the upgrade goals. We report on ongoing numerical studies aiming at estimating the e-cloud density threshold for the occurrence of single bunch instabilities or significant degradation of the beam emittance. We present selected results obtained in the more familiar quasi-static approximation and/or in the Lorentz-boosted frame.
IUCF, Bloomington, Indiana
ORNL, Oak Ridge, Tennessee
The instability caused by the electron cloud effect (ECE) may set an upper limit to beam intensity in proton storage rings. This instability is potentially a major obstacle to the full intensity operation, at 1.5·1014 protons per pulse, of the Spallation Neutron Source (SNS). High intensity experiments have been done with different sets of parameters that affect the electron-proton (e-p) instability, of which bunch intensity and bunch shape are considered as two main factors. In the experiment, the phase and amplitude of the second harmonic RF cavity are used to modify the bunch shape. Simulation with the beam dynamics code ORBIT has been carried out to compare with experimental results and to understand the impact of bunch shape on electron cloud build-up and beam stability. We have also attempted to benchmark the e-p model to predict the frequency spectrum and the RF buncher voltage threshold values against experimental results. Details and discussion will be reported in this conference.
* M.T.F. Pivi and M.A. Furman, PRSTAB 6, 034201 (2003)
** V. Danilov et. al, 39th ICFA Advanced Beam Dynamics Workshop, 2006
*** B. Macek et. al, PAC 2003
TUB, Beijing
Different kinds of accelerators, such as electron linacs, cyclotrons, microtrons, HV DC accelerators, synchrotrons and betatrons, can be used in radiotherapy, Non-Destructive Test, and irradiations. The accelerator industry in Asia almost covers all of the accelerators and application areas above. In this paper, the status and the trend of the accelerator industry in Asia will be introduced. Typical examples, in the areas of medial and industrial applications, will be described about their technology, achievement and relationship with universities or institutes. For the accelerator technology is strongly relied on the development of components, we will also briefly introduce the industry in Asia of some components, such as rf power sources, HV power sources (modulator), magnets and so on.
Varian Medical Systems, Oncology Systems, Palo Alto
Several projects for synchrotron light source facilities and medical accelerators are proposed in North America. Application of accelerators for homeland security system is also under consideration. Project X is a typical example of a big next generation accelerator project. The current status of the accelerator industry in North America will be presented.
KEK, Ibaraki
VXI-11 is an industrial standard to control equipments through network. A moule to control these equipments through Python scripting Language was developed. This module can be used for quick testing of equipments and for the rapid application development. The implementation of the module will be discussed and some application of the module will be reported.
CERN, Geneva
To cope with the large variety of different beams for the LHC, the RF beam control in the CERN PS has evolved continuously to improve its flexibility and reliability. Single-bunch beams, several different multi-bunch beams with 25, 50 or 75 ns bunch spacing at ejection for LHC filling, as well as two lead-ion beam variants are now regularly produced in pulse-to-pulse operation. The multi-bunch beam control for protons can be easily re-adjusted from 0.25·1011 to 1.3·1011 particles per ejected bunch. Depending on the number of bunches injected from the PS Booster, the length of the ejected bunch train may vary from 8 to 72 bunches. This paper summarizes recent improvements in the low-level RF systems and gives an outlook on the future consolidation.
Tokyo City University, Tokyo
KEK, Ibaraki
Miyazaki University, Miyazaki
NIRS, Chiba-shi
Tsukuba University, Ibaraki
J-PARC is a new accelerator facility to produce MW-class high power proton beams. From the main ring (MR) high energy protons are extracted in a slow extracted mode for hadron experiments. The beam is required with as small ripple as possible to prevent pileup events in particle detectors or data acquisition systems. We took beam tests at HIMAC using a prototype signal processing unit. In these beam tests we had recognized the improvement of the extracted beam structure by using the feedback algorithm whose parameters were changed according to the beam characteristics. We have developed a new signal processing unit for the spill feedback control of J-PARC. The unit consists of three signal input ports (gate, spill intensity and residual beam intensity), three signal output ports (spill control magnets), two DSPs (power spectrum analysis and spill feedback control), dual port memories, FPGAs and a LAN interface (remote control with SUZAKU-EPICS). From October 2009, this unit is being used in the beam study of J-PARC MR to check the performance of digital filtering, phase-shift processing, servo feedback control, real-time power spectrum analysis and adoptive control.
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.
CERN, Geneva
Poznań University of Technology, Poznań
The LHC beam loss measurement system is mainly used to trigger the beam abort in case a magnet coil quench level is approached. The predicted heat deposition in the superconducting coils of the magnets have been determined by particle shower simulation codes, while the liquid helium cooling capacity of the system has been both simulated and measured. The results have been combined to determine the abort thresholds. Measurements of the energy depositions of lost protons from the initial beams in the LHC are used to determine the accuracy of the beam abort threshold settings. The simulation predictions are reviewed and compared with the measurement results.
CERN, Geneva
Particle losses in the LHC arcs are mainly expected in the interconnection region between a dipole and quadrupole magnet. The maximal beam size, the maximal orbit excursion and aperture changes cause the enhancement of losses at this location. Extensive Geant4 simulations have been performed to characterise this particular region to establish beam abort settings for the beam loss monitors in these areas. Data from first LHC beam loss measurements have been used to check and determine the most likely proton impact locations. This input has been used to optimise the simulations used for the definition of thresholds settings. The accuracy of these settings is investigated by comparing the simulations with actual loss measurements.
CERN, Geneva
SLAC, Menlo Park, California
The LHC beam dump system relies on extraction kickers that need 3 microseconds to rise up to their nominal field. As a consequence, particles crossing the kickers during this rise time will not be dumped properly. The proton population during this time should remain below quench and damage limits at all times. A specific monitor has been designed to measure the particle population in this gap. It is based on the detection of Synchrotron radiation using a gated photomultiplier. Since the quench and damage limits change with the beam energy, the acceptable population in the abort gap and the settings of the monitor must be adapted accordingly. This paper presents the design of the monitor, the calibration procedure and the detector performance with beam.
CEA, Gif-sur-Yvette
Coaxial power couplers capable of handling 1MW peak power have been developped for high intensity superconducting proton linacs. They have been conditioned in travelling wave up to the maximum power available on the Saclay test bench, 1.2 MW forward peak power, up to 10% duty cycle. One coupler has been assembled on a 5-cell medium beta cavity in the class 10 area of the clean room, and installed in our horizontal test cryostat CryHoLab. This paper focusses on the RF operation of the coupler in this cryogenic environment and thermal aspects.
University of Delhi, Delhi
Fermilab, Batavia
A superconducting rf cavity is designed for acceleration of particles travelling at 81% the speed of light. The cavity will operate at 1.3 GHz & is to be used in SILC section of the proposed high intensity proton linac at Fermilab. At present cavity will serve to accelerate the particles for energy range 466 MeV to 1.2 GeV. The cavity will be shorter than 9 cell beta =1 cavity but nearly same ratio of surface magnetic field to surface electric field. Cell to cell coupling coefficient is also optimized to get the good field flatness. The cavity is studied for monopole modes and higher order modes. The shapes of end cells are optimized to avoid dangerous modes with keeping same field flatness & same operating frequency.
KAERI, Daejon
PAL, Pohang, Kyungbuk
A superconducting RF cavity with a geometrical beta of 0.42 and a resonant frequency of 700 MHz has been under investigation for an extension program of Proton Engineering Frontier Project (PEFP) to accelerate the proton beam above 100 MeV. We developed and tested a two-cell prototype in order to confirm the fabrication procedure and check the RF and mechanical properties of such a low-beta elliptical cavity. The prototype has been fabricated with high RRR niobium sheets (RRR > 250). Double-ring structure was adopted to reduce the Lorentz force detuning effect. For the vertical test of the prototype cavity, a cryostat was designed and fabricated. Operating temperature is 4.2 K, therefore, pumping to reduce the pressure is not required. We applied 40 layers of superinsulation around the helium vessel in addition to the vacuum insulation between the helium vessel and outer chamber. The status of the prototype development and RF test results will be presented in this paper.
JLAB, Newport News, Virginia
JLab has designed and fabricated several prototype SRF cavities with cell shapes optimized for high current beams and with strong damping of unwanted higher order modes. We report on the latest test results of these cavities and on developments of concepts for new variants optimized for particular applications such as light sources and high-power proton accelerators, including betas less than one. We also report on progress towards a first beam test of this design in the recirculation loop of the JLab ERL based FEL. With growing interest worldwide in applications of SRF for high-average power electron and hadron machines, a practical test of these concepts is highly desirable. We plan to package two prototype cavities in a de-mountable cryomodule for temporary installation into the JLab FEL for testing with RF and beam. This will allow verification of all critical design and operational parameters paving the way to a full-scale prototype cryomodule.
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken
3 GeV rapid cycling synchrotron (RCS) of J-PARC accelerates proton beams from the 181 MeV up to 3 GeV. The RCS injects the beam to the Main Ring and transports it to the muon production target and neutron production target in the Materials and Life Science Experimental Hall. Proton beams in the RCS are fast extracted by kicker magnets at the repetition rate of 25 Hz. The rise time of the magnetic field is approximately 260 ns due to the propagation time through the coaxial cable and the kicker magnet itself. The flat-top length of it is required to 840 ns in order to extract two beam bunches. Pulse forming lines (PFL) and thyratrons are used to make the rise time and the flat-top, at the maximum charging voltage of 80 kV. Two thyratrons, which is a CX1193C made by e2V Ltd., are used for a power supply. 16 thyratrons are used in the eight power supplies of the kicker system. Since thyratrons are gaseous discharge switching devices, they often make misfire or self-breakdown in several hours. In this paper, present status of operation and voltage adjustment method of the reservoir and cathode heater power supply of the thyratrons in the kicker system are described.
STFC/RAL/ISIS, Chilton, Didcot, Oxon
A description is given of the development of slow-wave chopper structures for the 3.0 MeV, 60 mA, H‾ MEBT on the RAL Front-End Test Stand (FETS) [1]. 'Helical' and 'Planar' electrode designs [2] have been developed by simulating their high frequency (HF) electromagnetic properties in a commercial 3D code [3], and the manufacture of prototypes has helped to validate the predictive accuracy of the design code, and the selection of suitable machine-able ceramics and alloys of copper and aluminium. A description is also given of a novel abrasive brushing process that enables fine tuning of stripline characteristic impedance by facilitating control of stripline edge radius. The transmission line properties of the previously described 'Helical' test assembly [4] are compared with those of the recently completed 'Planar' test assembly. Finally, the development status of a related prototype high voltage pulse generator is presented.
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.
IHEP Beijing, Beijing
MPI-P, München
MPI für Physics, Muenchen
Low energy muon beams are useful for a wide range of physics experiments. High quality muon beams are also required for muon colliders and neutrino factories. The frictional cooling method holds promise for delivering slow muon beams with narrow energy spreads. With this technology, we consider the production of a cold muon beam from a surface muon source, such as that at the Paul Scherrer Institute. A cooling scheme based on frictional cooling is outlined. Simulation results show that the efficiency of slow muon production can be raised to 1%, which is significantly higher than current schemes.
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
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
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
Imperial College of Science and Technology, Department of Physics, London
To demonstrate the feasibility of a high pressure RF cavity for use in the cooling channel of a muon collider, an experimental setup that utilizes 400-MeV Fermilab linac proton beam has been developed. In this paper, we describe the beam diagnostics and the collimator system for the experiment, and report the initial results of the beam commissioning. The transient response of the cavity to the beam is measured by the electric and magnetic pickup probes, and the beam-gas interaction is monitored by the optical diagnostic system composed of a spectrometer and two PMTs.
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.
LBNL, Berkeley, California
BNL, Upton, Long Island, New York
A Neutrino Factory requires an intense and highly cooled (in transverse phase space) muon beam. We discuss a hybrid approach for a linear 4D cooling channel consisting of high-pressure gas-filled RF cavities –potentially allowing high gradients without breakdowns– and discrete LiH absorbers to provide the necessary energy loss that results in the needed muon beam cooling. We report simulations of the channel performance and its comparison with the vacuum case; we also discuss the various technical and safety issues associated with cavities filled with high-pressure hydrogen gas. Even with additional windows that might be needed for safety reasons, the channel performance is comparable to that of the original, all-vacuum Feasibility Study 2a channel on which our design is based. If tests demonstrate that the gas-filled RF cavities can operate properly with an intense beam of ionizing particles passing through them, our approach would be an attractive way of avoiding possible breakdown problems with a vacuum RF channel.
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.
KAERI, Daejon
Since launched in 2002 to develop a high current 100 MeV, 20 mA proton linac and beam facilities, the Proton Engineering Frontier Project has fully developed and integrated the low energy part, consisting of a 50 keV ion source, 3 MeV RFQ, and 20 MeV DTL with a 24% high duty factor. Successfully commissioned by achieving the designed peak beam current of 20 mA and beam energy of 20 MeV, the linac started user beam services in 2007 with limited operation conditions. Fabrication of the high energy part of the linac, composed of seven DTL tanks, and components of the 20 MeV and 100 MeV beam facilities are underway. The 20 MeV and 100 MeV beam facilities consist of five beamlines, respectively, and are designed to deliver characterized proton beams for applications in various fields by meeting user requirements. In addition, site preparation and construction works are in progress. Being completed in early 2012 as scheduled, the proton linac facility will be utilized in core R&D projects in multi-disciplines, from nano, bio-life, materials, energy, environment, and medical, to basics science.
BNL, Upton, Long Island, New York
High energy polarized proton beams are desired for exploring the proton spin structure as well as other spin dependent measurements. However, depolarizing mechanisms due to the interaction between the spin motion and the magnetic fields challenges accelerating polarized protons to high energy in circular accelerators. Several decades of efforts in developing techniques to preserve polarization to high energy have finally led to the success of the polarized proton program at the Brookhaven Relativistic Heavy Ion Collider (RHIC). Designed to provide polarized proton collisions up to 250GeV, RHIC is equipped with two Siberian snakes to avoid both intrinsic and imperfection depolarizing resonances. Currently, polarization has been preserved up to 100 GeV at RHIC with precise control of orbit and betatron tunes. The polarized protons were first brought into collisions at 250GeV in RHIC in 2009, and depolarizations were observed between 100 GeV to 250 GeV. This presentation reports the progress of RHIC polarized proton program. Strategies of how to preserve the polarization through the RHIC injectors are also presented.
KEK, Ibaraki
For future high-intensity positron or proton accelerators, beam instability caused by electron cloud is one of the most important problems. Some coatings on inner surface of beam chambers with materials having low secondary emission yields such as titanium nitride (TiN), non-evaporable getter and so on have represented good effects against the electron cloud instability. In this study, diamond like carbon (DLC) and TiN coated chambers, and a copper chamber without coating were installed to an arc section of KEKB LER to make comparisons of total pressure, residual gas components and electron cloud activity during the beam operation under the same condition. Residual gas observation for the DLC coating revealed much higher hydrogen gas desorption because a process gas including hydrogen was used for the film growth. No remarkable hydrocarbon gas desorption was found. On the other hand, a mass peak of amu=14, that is N+ was prominent in the TiN coating. The electron cloud activity in the DLC coating was lower than the TiN coating and the copper chamber.
KEK, Ibaraki
In J-PARC 50GeV synchrotron ring, large vacuum pressure rises above 10-3 Pa are found at 30GeV acceleration final stage of intensity over 1013 protons per pulse in the chambers of the in-vacuum electrostatic septum magnet for the slow-extraction(SX), magnetic septum for SX, and the kicker magnet for the fast-extraction. This pressure rise depends on beam intensity and peak-current, and can be reduced by continuous beam operations, such as scrubbing with proton beam, secondary emission electrons and other cations of remaining gasses or desorptions.
IAP, Frankfurt am Main
The beam transport experiments in toroidal magnets were first described in EPAC08 within the framework of a proposed low energy ion storage ring at Frankfurt University. The experiments with two room temperature 30 degree toroids are needed to design the accumulator ring with closed magnetic fields up to 6~8T. The test setup aims on building an injection system with two beam lines. The primary beam line for the experiments was installed and successfully commissioned in 2009. A special probe for ion beam detection was installed. This modular technique allows online diagnostics of the ion beam along the beam path. In this paper we present new results on beam transport experiments and discuss transport and transverse beam injection properties of that system.
National Technical University of Athens, Zografou
CERN, Geneva
Dispersion and beam optics measurements were carried out in the transfer line between the CERN PS and SPS for the new Multi-Turn Extraction beam. Since the extraction conditions of the four islands and the core are different and strongly dependent on the non-linear effects used to split the beam in the transverse plane, a special care was taken during the measurement campaigns. Furthermore, an appropriate strategy was devised to minimize the overall optical mismatch at SPS injection. All this led to a new optical configuration that will be presented in detail in the paper.
University of Fukui, Faculty of Engineering, Fukui
KEK, Ibaraki
KURRI, Osaka
In Kyoto University Research Reactor Institute (KURRI), the FFAG accelerator for accelerator driven sub-critical reactor (ADSR) system has been constructed and world's first ADSR experiments have started in March 2009. In order to upgrade beam intensity, multiturn charge exchange injection system for scaling FFAG accelerator is being studied. The 11MeV H- beam is injected from linac and is accelerated up to 100MeV in FFAG main ring. In this presentation, the detail of injection system is described and feasibility of such a low energy H- injection system is discussed.
KEK, Ibaraki
Thick carbon foils (>300ug/cm2) has been used for stripping of H- ion beam into protons at the injection stage of the 3GeV Rapid Cycling Synchrotron (3GeV-RCS) in J-PARC. The carbon stripping foils with high durability at high temperature >1800K are strongly required. We have recently developed a new irradiation system for lifetime measurement of the stripping foils using the KEK 650keV Cockcroft-Walton type of high voltage accelerator with high current pulsed negative hydrogen ion beam, which can simulate the high energy-depositions upon foils in the RCS. It is found that, by adjusting the peak intensity and the pulse length of the hydrogen ion beams appropriately, the energy deposition becomes equivalent to that exerted by the incoming hydrogen ions and the circulating protons at the injection process of the RCS. The most important factor that affects the foil lifetime is the foil temperature. During lifetime tests by this system, the temperature of foil is measured by a fast thermometer and by using a phototransistor in a pulsed mode (650keV, 10mA, 0.25msec, 25Hz). The new irradiation system and some preliminary results on lifetime of the carbon stripping foil will be presented.
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken
KEK, Ibaraki
J-PARC requires thick carbon stripper foils to strip electrons from the H- beam supplied by the linac before injection into the Rapid Cycling Synchrotron (RCS). Foil thickness is about 200 μg/cm2 corresponding to conversion efficiency of 99.7% from the primary H- beams of 181MeV energy to H+. For this purpose, we have successfully developed hybrid type thick boron-doped carbon (HBC) stripper foils, which showed a drastic improvement not only with respect to the lifetime, but also with respect to thickness reduction and shrinkage at high temperature during long beam irradiation. We started to study carbon stripper foils microscopically why carbon foils have considerable endurance for the beam impact by boron-doped. At first, we made a comparison between nominal carbon and HBC by the electric microscope and ion-induced analysis. In this paper, we will introduce some results for characteristics of HBC foils.
CERN, Geneva
Within the scope of the LHC injector upgrade, it is proposed to replace the present injector chain by new accelerators, Linac4, SPL and PS2, for which new beam transfer lines are required. The beam properties and requirements for each of the lines are summarized. The original design of the beam lines has been fully reconsidered due to the very demanding constraints on the beam line layouts at the PS2 injection / extraction regions and a new straight section of the PS2 which led to a much improved beam line geometry. The relevant modifications and optics designs are described and a preliminary specification of the beam line equipment is also given.
CERN, Geneva
Beam physics considerations for the stripping foil of the 160 MeV PSB H- injection system are described, including the arguments for the foil type, thickness, geometry and positioning. The foil performance considerations are described, including expected stripping efficiency, emittance growth, energy straggling, temperature and lifetime. The different beam loss mechanisms are quantified in the context of the aperture limits, operational considerations and collimation requirements.
Imperial College of Science and Technology, Department of Physics, London
STFC/RAL, Chilton, Didcot, Oxon
JAI, Egham, Surrey
For the PAMELA medical non-scaling FFAG, carbon 6+ as well as proton particles are required. The general injection layout based on a cyclotron for proton and a Linac for carbon is considered. There are two options for pre-accelerating carbon ions for PAMELA, either accelerating carbon with the charge state 4+ from the ion source and stripping after the pre-accelerator or directly accelerating carbon 6+ ions all the way from the ion source. For both options solution has been investigated. Simulations of beam dynamics for both particle species are presented. The resulting schemes based on either the single turn or multiturn injection into the first FFAG ring are discussed.
Imperial College of Science and Technology, Department of Physics, London
JAI, Egham, Surrey
The PAMELA medical FFAG complex under design in the UK, aims to operate with both proton and carbon beams for hadron therapy. Medium energy beam transfer(MEBT) of PAMELA consists of the proton beam line coming out of the injector cyclotron, carbon beam transfer from the independent carbon 6+ injector linac, switching dipole when both beam merge and transfer line toward the PAMELA NS-FFAG. The MEBT layout and design, which needs to incorporate the beam chopper for the intensity modulation are discussed. The careful matching of optical functions between various components in the MEBT and beam dynamics simulations are presented.
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.
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
Fermilab, Batavia
The NOνA Experiment will construct a detector optimized for electron neutrino detection in the existing Neutrino at Main Injector (NuMI) beamline. This beamline is capable of operating at 400 kW of primary beam power and the upgrade will allow up to 700 kW. The cavities will operate at 53 MHz and three of them will be installed in the Recycler beamline. Thermal stability of the cavities is crucial since this affects the tuning. Results of finite element thermal and structural analysis involving the copper RF cavity will be presented.
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.
ESS Bilbao, Bilbao
Bilbao, Faculty of Science and Technology, Bilbao
University of the Basque Country, Faculty of Science and Technology, Bilbao
ESS-Bilbao, Zamudio
Imperial College of Science and Technology, Department of Physics, London
STFC/RAL/ISIS, Chilton, Didcot, Oxon
The main objective of the Bilbao Front End Test Stand (ETORFETS) is to set up a facility to demonstrate experimentally the design ideas for the future ESS LINAC that are being proposed in discussion forums by the technical scientific community. ETORFETS is focused on the first stage of the linear accelerator, namely, that of the Radio-Frequency Quadrupole (RFQ) and its pre and post beam transport systems. The RFQ bunches, focuses transverse and longitudinally, and accelerates charged particles in the low-energy range (up to ~ 3 MeV), thus becoming one of the main components of the accelerating structure. The first RFQ simulations, performed in Superfish and GPT software packages, will be presented in this work.
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.
CERN, Geneva
INFN-Roma, Roma
The UA9 experiment was performed in 6 MDs from May to November 2009 with the goal of studying the collimation properties of a crystal in the framework of a future exploitation in the LHC collimation system. An important parameter evaluated for the characterization of the crystal collimation is the efficiency of halo extraction when the crystal is in channeling mode. In this paper it is explained how this efficiency can be measured using a pixel detector, the Medipix, installed in the Roman Pot of UA9. The number of extracted particles counted by the Medipix is compared with the total number of circulating particles measured by the Beam Current Transformers (BCTs): from this comparison the efficiency of the system composed by the crystal, used in channeling mode, and a tungsten absorber is proved to be greater than 85%.
CERN, Geneva
JINR, Dubna, Moscow Region
A number of tests were performed by the UA9 Collaboration* in the North area of the SPS in view of investigating crystal-particles interactions for future application in hadron colliders. The rate of nuclear reactions was measured with 400 GeV proton beams directed into a silicon bent crystal. In this way the background induced by the crystal itself either in amorphous or in channeling orientation was revealed. The results provide fundamental information to put in perspective the use of silicon crystals to assist halo collimation in hadron colliders, whilst minimizing the induced loss. Crystals made of Germanium were also investigated in view of the expected increase of the collimation efficiency respect to silicon. Finally, crystals were tested in axial orientation and with incoming particles of negative charge. The collected results are presented in details.
* http://greybook.cern.ch/programmes/experiments/UA9.html
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.
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.
UBC & TRIUMF, Vancouver, British Columbia
TRIUMF, Vancouver
This paper describes tracking studies of non-scaling (NS) FFAGs using cyclotron codes in place of the more conventional lumped-element synchrotron codes. The equilibrium orbit code CYCLOPS determines orbits, tunes and period at fixed energies, while the general orbit code GOBLIN tracks a representative bunch of particles through the acceleration process. Results will be presented for the EMMA linear NS-FFAG under construction at Daresbury (10-20 MeV electrons), and for two non-linear NS-FFAG designs: Rees's isochronous IFFAG (8-20 GeV muons) and Johnstone's design for ADSR (250-1000 MeV protons). Our results are compared with those obtained using lumped-element codes. In the case of EMMA, results are presented for both the measured and design fields.
HHUD, Dusseldorf
National University of Defense Technology, Changsha, Hunan
By using multi-dimensional particle-in-cell simulations, we investigate the stability of proton beam acceleration in a two-specie ultra-thin foil. In this two-specie regime, the lighter protons are initially separated from the heavier carbon ions due to their higher charge-to-mass ratio Z/m. The laser pulse is well-defined so that it doesn't penetrate the carbon ion layer. The Rayleigh-Taylor-like (RT) instability seeded at the very early stage then only degrades the acceleration of the carbon ions which act as a "cushion" for the lighter protons. Due to the absence of proton-RT instability, the produced high quality mono-energetic proton beams can be well collimated even after the laser-foil interaction concludes.
IAP, Frankfurt am Main
GSI, Darmstadt
The concept of laser acceleration of protons by Target Normal Sheath Acceleration TNSA from thin foils could be used to produce a high intensity proton bunch. This proton bunch could be injected into a linac at energies of ten to several tens MeV. A CH- structure is suggested as the linac structure because of its high gradient. The motivation for such a combination is to deliver single beam bunches with quite small emittance values of extremely high particle number - in the order of 10 billion protons per bunch. Optimum emittance values for linac injection are compared with available, laser generated beam parameters. Options and simulation tools for beam matching by pulsed solenoid and CH- structure using LASIN and LORASR codes are presented.
Rome University La Sapienza, Roma
INFN/LNF, Frascati (Roma)
ENEA C.R. Frascati, Frascati (Roma)
Protons generated by the irradiation of a thin metal foil by a high-intensity short-pulse laser have shown to posses interesting characteristics in terms of energy, emittance, current and pulse duration. They might therefore become in the next future a competitive source to conventional proton sources. Previous theoretical and numerical studies already demonstrated the possibility of an efficient coupling between laser-plasma acceleration of protons with traditional RF based beam-line accelerator techniques. This hybrid proton accelerator would therefore benefit from the good properties of the laser-based source and from the flexibility and know-how of beam handling as given from RF based accelerator structure. The proton beam parameters of the source have been obtained from published laser interaction experimental results and are given as input to the numerical study by conventional accelerator design tools. In this paper we discuss recent results in the optimization and design of the such hybrid schemes in the context of proton accelerators for medical treatments.
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.
MPI-P, München
CERN, Geneva
BINP SB RAS, Novosibirsk
HHUD, Dusseldorf
Proton driven plasma wakefield acceleration holds promise to accelerate a bunch of electrons to the energy frontier in a single acceleration channel. To verify this novel idea, a demonstration experiment is now being planned. The idea is to use the high energy proton bunches from the Super Proton Synchrotron (SPS) at CERN, to shoot them into a plasma cell and drive large amplitude of plasma wake. The interactions between the plasma and protons are simulated and the results are presented in this paper.
MPI-P, München
A high energy, intense and short proton bunch can be employed to excite an interesting plasma wakefield for the electron beam acceleration. To excite a large amplitude of plasma wave, a short driver is thus required. In this paper, several proton bunch compression scenarios are analyzed. A magnetic bunch compressor is designed to compress the SPS proton beam for the demonstration experiment at CERN. The simulation results of bunch compression are given.
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).
BNL, Upton, Long Island, New York
Imperial College of Science and Technology, Department of Physics, London
UMD, College Park, Maryland
Stony Brook University, StonyBrook
Recent theoretical and experimental studies point to better efficiency of laser-driven ion acceleration when approaching the critical plasma density regime. Simultaneously, this is the condition for observing solitons: "bubble"-like quasi-stationary plasma formations with laser radiation trapped inside. Exploring this regime with ultra-intense solid state lasers is problematic due to the lack of plasma sources and imaging methods at ~1021/cc electron density. The terawatt picosecond CO2 laser operated at Brookhaven's Accelerator Test Facility offers a solution to this problem. At 10 μm laser wavelength, the CO2 laser shifts the critical plasma density to 1019/cc which is attainable with gas jets and can be optically probed with visible light. Capitalizing on this approach, we focused a circular-polarized CO2 laser beam with a0=0.5 onto a hydrogen gas jet and observed monoenergetic proton beams in the 1 MeV range. Simultaneously, the laser/plasma interaction region has been optically probed with a 2nd harmonic picosecond Nd:YAG laser to reveal stationary soliton-like plasma formations. 2D PIC simulations agree with experimental results and aid in their interpretation.
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.
IAP, Frankfurt am Main
The stellarator-type storage ring for multi- Ampere proton and ion beams with energies in the range of 100 AkeV to 1AMeV was designed. The main idea for beam confinement with high transversal momentum acceptance was presented in EPAC06 and EPAC08. Stable beam transport in opposite directions is possible through the same aperture with two crossing points along the structure. Elsewhere the beams are separated by the RxB drift motion in curved sections. The space charge compensation through the trapped or circulated electrons will be discussed. This ring is typically suited for experiments in plasma physics and nuclear astrophysics. Here we present the complete simulations for optimization of ring geometry, a stable beam confinement and developments in beam injection.
DAE/VECC, Calcutta
A cylindrical lens is mainly used for focusing and transporting low energy beam. Some analytical forms of scalar potential have been formulated to evaluate electric and magnetic field and its derivatives on the central axis, which help in evaluation of potential and field in the region about the central axis. They are, subsequently, used to analytically find out the optical properties of a lens as well as in tracking of charged particles. It turns into a tool to design an electrostatic or a magnetic cylindrical lens. A section-technique has been developed to evaluate the optical cardinal points of a thick lens very accurately. Smooth profiles of the field and potential along the axis are divided into large number of small stepped profile. Each step represents a weak thin lens as change in radial movement is very small. The effect of the individual weak lenses is evaluated and combined by matrix multiplication method to get optical property of the thick lens. The obtained values are verified by exactly tracking the particles by solving the Lorentz equation of motion of charged particle in electric or magnetic field.
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.
BINP SB RAS, Novosibirsk
Fermilab, Batavia
One of the possible ways to increase luminosity of hadron colliders is the compensation of beam-beam tune-spread with an electron lens (EL). At the same time, EL as an additional nonlinear element in the lattice can increase strength of nonlinear resonances so that its overall effect on the beam lifetime will be negative. Time-consuming numerical simulations are often used to study the effects of the EL. In this report we present a simplified model, which uses analytical formulae derived for certain electron beam profiles. Based on these equations the idealized shapes of the compressed tune spread can be rapidly calculated. Obtained footprints were benchmarked against several reference numerical simulations for the Tevatron in order to evaluate the selected configurations. One of the tested criteria was the so-called "folding" of the compensated footprint, which occurs when particles with different betatron amplitudes have the same tune shift. Also studied were the effects of imperfections, including misalignment of the electron and proton beams, and mismatch of their shapes.
CERN, Geneva
The CERN Proton Synchrotron has been continuously improving its beam performances since 1959. The working point parameters of the accelerator are mainly controlled by dedicated windings installed on the poles of the main combined function magnets. In 2007, the power supplies of these windings were renovated and extended from three to five independent groups, allowing exploration of new working point settings. This configuration offers the flexibility of several adjustment strategies such as leaving one current free or to control an additional physical parameter, like Q''h. A non-linear chromaticity measurement campaign, at different beam energies, resulted in matrices defining the relationship between the five pole face winding currents and the four beam parameters Qh, Qv, Xih, and Xiv. Each cell of these matrices was fitted against energy. The final result is a single matrix which is now used by the operational software to trim the working point. This paper summarises this measurement campaign by presenting the resulting matrix with a brief overview of the adjustment tools and strategy. Furthermore a few future possible benefits of this control enhancement will be discussed.
BNL, Upton, Long Island, New York
Polarized proton beams are accelerated in RHIC to 250 GeV energy with the help of Siberian Snakes. The pair of Siberian Snakes in each RHIC ring holds the design spin tune at 1/2 to avoid polarization loss during acceleration. However, in the presence of closed orbit errors, the actual spin tune can be shifted from the exact 1/2 value. It leads to corresponding shift of locations of higher-order ("Snake") resonances and limits available betatron tune space. The largest closed orbit effect on the spin tune comes from the horizontal orbit angle between the two snakes. During RHIC Run in 2009 dedicated measurements with polarized proton beams were taken to verify the dependence of the spin tune on the local orbits at the Snakes. The experimental results are presented along with the comparison with analytical predictions.
BNL, Upton, Long Island, New York
SBU, Stony Brook, New York
The RHIC beam lifetime in polarized proton operation is dominated by the beam-beam effect, parameter modulations, and nonlinear magnet errors in the interaction region magnets. Sextupole and skew sextupole errors have been corrected deterministically for a number of years based on tune shift measurements with orbit bumps in the triplets. During the most recent polarized proton run 10- and 12-pole correctors were set through an iterative procedure, and used for the first time operationally in one of the beams. We report on the procedure to set these high-order multipole correctors and estimate their effect on the integrated luminosity.
BNL, Upton, Long Island, New York
Electron lenses for the head-on beam-beam compensation are under construction at the Relativistic Heavy Ion Collider. The bunch length is of the same order as the beta-function at the interaction point, and a proton passing through another proton bunch experiences a substantial phase shift which modifies the beam-beam interaction. We review the effect of the bunch length in the single pass beam-beam interaction, apply the same analysis to a proton passing through a long electron lens, and study the single pass beam-beam compensation with long bunches.
BNL, Upton, Long Island, New York
An electron lens was proposed to compensate the head-on beam-beam effect for polarized proton operations in the Relativistic Heady Ion Collider (RHIC). With head-on beam-beam compensation, we plan to reduce the beam-beam tune footprint and increase the beam-beam parameter to increase the luminosity. Here we carry out 6-D weak-strong beam-beam simulations to study the stability of proton particles and the proton beam lifetime in the presence of head-on beam-beam compensation. The effects and tolerances of the errors and noises in the compensation are also calculated.
CERN, Geneva
The CLOUD Project, where a high-energy physics accelerator is being used to study atmospheric and climate science for the first time, will be described.
KIT, Karlsruhe
KCETA, Eggenstein-Leopoldshafen
Cosmic ray particles can produce extended air showers that have a total energy of more than 100 EeV, which is a hundred million times more than the TeV particles that we produce in accelerators. How do the cosmic accelerators work? Where are they and what are they accelerating? How do the supposedly extragalactic particles propagate to Earth? Do they offer a new kind of astronomy? The Pierre Auger Observatory is an international project dedicated to find answers to these - and many more - questions. The presentation reviews the goals, achievements and plans for a better understanding of ultra-high energy cosmic rays.