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.
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.
Muons, Inc, Batavia
Fermilab, Batavia
A compact tunable gamma ray source has many potential uses in medical and industrial applications. One novel scheme to produce an intense beam of gammas relies on the ability to create a high flux of positrons. We present various positron production methods that are compatible with this approach for producing the intense beam of gammas.
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.
RCNP, Osaka
The RCNP accelerator cascade consists of an injector Azimuthally Varying Field (AVF) cyclotron (K=140) and a ring cyclotron (K=400). It provides ultra-high-quality beams and moderately high-intensity beams for a wide range of research in nuclear physics, fundamental physics, applications, and interdisciplinary fields. The maximum energy of protons and heavy ions are 400 and 100 MeV/u, respectively. Experimental apparatuses are used like a pair spectrometer, a neutron time of flight facility with a 100 m long tunnel, a radioactive nuclei separator, a super-thermal ultra cold neutron (UCN) source, a white neutron source, and a RI production system for nuclear chemistry. Such ultra high resolution measurements as dE/E = 5x10-5 are routinely performed with the Grand-Raiden spectrometer by utilizing the dispersion matching technique. The UCN density was observed to be 15 UCN/cm3 at the experimental port at a beam power of 400 W. Some topics on the research are discussed in the talk.
Air Liquide, Division Techniques Avancées, Sassenage
F4E, Barcelona
STFC/RAL/ISIS, Chilton, Didcot, Oxon
ANSTO, Menai, New South Wales
Thanks to its experience in past projects in the field of neutron sources, Air Liquide DTA was involved in recent years in two major projects : a new Cold Neutron Source (OPAL) at ANSTO, Australia and a Spallation Neutron Source at ISIS, United Kingdom. The OPAL CNS is a liquid deuterium moderated source operating with a cold box with a refrigeration capacity of 5 kW at 25K designed and manufactured by Air Liquide DTA. ISIS Target Station 2 is a liquid hydrogen and solid methane moderated source for which Air Liquide DTA provided two Helium cold boxes (about 600W) operating at 20K derived from the standard Helial product, one customised cryogenic hydrogen loop, and very specific remote dismountable cryogenic transfer lines. These two cryogenic systems were fully commissioned on Air Liquide DTA dedicated test area before delivery to the customers. The purpose of this paper is to give a compared overview of the design and testing of the proposed cryogenic systems for these two projects.
INFN/LNF, Frascati (Roma)
INFN-Roma, Roma
A neutron source, based on photo-neutron production, has been designed and is under construction to upgrade the electron/positron/photon DAΦNE Beam Test Facility (BTF). We present the feasibility study, the solution chosen and the optimization done in order to maximize the neutron/photon yield as well as the comparison between different simulation codes (FLUKA/GEANT4/MCNPX). The first experimental test is foreseen in March 2010.
University of Fukui, Faculty of Engineering, Fukui
KURRI, Osaka
As for BNCT (boron neutron capture therapy) medical applications, an accelerator-based intense thermal or epithermal neutron source has been strongly requested recently. A scaling type of FFAG accelerator with ERIT (energy/emittance recovery internal target) scheme has been developed for this purpose. In this scheme, the beam emittance degradation caused by the neutron production target are cured by ionization cooling method. In this presentation, recent beam study of ionization cooling and neutron production will be described.
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken
KEK/JAEA, Ibaraki-Ken
In J-PARC, Materials and Life Science experimental Facility (MLF) is aimed at promoting experiments using the world highest intensity pulsed neutron and muon beams which are produced at a thick mercury target and a thin carbon graphite target by 3-GeV proton beams, respectively. The first beam was achieved at the target without significant beam loss in May 2008. It is succeeded stable operation with beam power of larger than 300 kW. After beam irradiation, the residual dose of radiation on the beam transport line is remarkably small where the highest dose is 20 microSv/h. In order to confirm stable operation of the facility, especially for the wellness of the target, it is important to obtain the beam profile at the target. We developed new technique by using imaging plate which is attached on the target vessel by remote handling technique via master slave manipulators. It is found that the beam profile shows good agreement with the calculation. It is also found that the beam scattering effect on the muon production target shows good agreement with the simulation calculation.
Kyoto ICR, Uji, Kyoto
ILL, Grenoble
RID, Delft
ANL, Argonne
KURRI, Osaka
RIKEN, Wako, Saitama
ANSTO, Menai
KEK, Ibaraki
We have developed a motorized magnetic lens for focusing of pulsed white neutron beams. The lens is composed of two concentric permanent magnet arrays, in sextupole geometry, with bore of 15 mm and magnet length of 66 mm. The inner magnet array is stationary, while the outer array is rotated (the frequency of the modulation of magnetic field inside the bore ν ≤ 25Hz), providing a sextupole magnetic field gradient range of 1.5x104T/m2 ≤ g' ≤ 5.9x104T/m2. By synchronization of a pulsed neutron beam with the sinusoidal modulation of the magnetic field in the lens, the beam is focused, without significant chromatic aberration, over a wide neutron wavelength band. We have constructed a focusing-SANS (Small Angle Neutron Scattering) test bed on the PF2-VCN (Very Cold Neutron) beam line at the Institut Laue-Langevin in Grenoble. The beam image size matched the source size (≈ 3mm) over of wavelength range of 30Å ≤ λ ≤ 48Å with focal length of ~ 2.3 m. Further, we have demonstrated the performance of this device for high resolution time-of-flight (tof) SANS for a selection of polymeric & biological samples, in a compact geometry of just 5 m.
Kyungpook National University, Daegu
POSTECH, Pohang, Kyungbuk
PAL, Pohang, Kyungbuk
CHEP, Daegu
We report the activities by using the pulsed neutron facility which consists of an electron linear accelerator, a water-cooled Ta target, and a 12-m time-of-flight path. It can be possible to measure the neutron total cross-sections in the neutron energy range from 0.01 eV to few hundreds eV by using the neutron time-of-flight method. A 6LiZnS(Ag) glass scintillator was used as a neutron detector. The neutron flight path from the water-cooled Ta target to the neutron detector was 12.1 m. The background level was determined by using notch-filters of Co, In, Ta, and Cd sheets. In order to reduce the gamma rays from Bremsstrahlung and those from neutron capture, we employed a neutron-gamma separation system based on their different pulse shapes. The present measurements of several samples (Dy, Nb) are in general agreement with the evaluated data in ENDF/B-VII. The resonance parameters were extracted from the transmission data from the SAMMY fitting and compared with the previous ones. We also report the isomeric yield ratios for isomeric pairs produced from photonuclear reactions by using the bremsstrahlung photons from the 70-MeV electron linac.
IAP, Frankfurt am Main
IKF, Frankfurt-am-Main
An intense 2 MeV, 200 mA proton beam will drive a neutron source by the reaction Li7(p,n)Be7 on solid as well as on liquid lithium targets. Actually, the facility is under construction at the physics faculty new experimental hall in Frankfurt. To study in detail the burning of elements in stars by the s-process, a pulsed beam operation with a bunch compressor at the linac exit will offer several Ampere beam current within 1 ns pulse length and with 250 kHz rep. rate at the n - production target. As the upper limit of generated neutrons and the total n- flux at this source are well defined the sample for neutron capture measurements can be placed after a time of flight path as short as 0.8 m only. This will provide highest accessible pulsed neutron flux rates for neutron energies in the 1 - 500 keV range. The highly space charge dominated bunch forming process as well as the ion source, the rf coupled 175 MHz RFQ/DTL - resonator and the target development will be explained.
JAEA/J-PARC, Tokai-mura
The J-PARC 3-GeV rapid cycling synchrotron (RCS) has been operated for the neutron and MLF users program from December 23rd, 2008. The RCS operations not only in support of the MLF but also were providing beam to support commissioning of the MR. In parallel we are challenging to realize higher beam power operations with better stability. Before scheduled maintenance last summer beam power was limited by the front end of about 20 kW, after that maintenance the RCS has been operated the beam power of more than 100 kW for MLF users. After beam deliver operation to the MR and MLF, while the priority has been given to their beam tuning, the RCS also continues further beam studies toward higher beam intensity. On December 7th, 2009, the RCS achieved the beam power of more than 300kW to the neutron production target with 25Hz. This presentation will concentrate itself on the outcome of the J-PARC RCS commissioning program, including the discussion on the issues of the high-power operation.
TUB, Beijing
LANL, Los Alamos, New Mexico
IHEP Beijing, Beijing
NUCTECH, Beijing
CIAE, Beijing
Institute of Physics, Chinese Academy of Sciences, Beijing
IMP, Lanzhou
Tsinghua University, Beijing
CERN, Geneva
This paper reports the design and construction status, technical challenges, and future perspectives of the proton-linac based Compact Pulsed Hadron Source (CPHS) at the Tsinghua University, Beijing, China.
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.
JAEA, Rokkasho, Kamikita, Aomori
NIFS, Gifu
Tohoku University, School of Engineering, Sendai
Doshisha University, Graduate School of Engineering, Kyoto
We propose a negative ion beam probe system as a new scheme to diagnose beam profile of high power positive ion beams. Two RF linacs of IFMIF have to drive the neutron source by providing continuous-wave (CW) positive deuterium ion beams with the intensity of 125 mA each at the beam energy of 40 MeV. During the CW beam operations, the extreme intensity of the beam and the severe radiation levels make the beam diagnostics with conventional techniques in the transport lines terribly difficult. A beam of negative ions liable to lose the additional electron at the occasion of impact with a high energy particle can work as a probe to measure the positive ion beam profile. On possible configuration to achieve high intensity beam profile measurement is to inject a negative ion probe beam into the target beam perpendicularly, and measure the attenuation of the negative ion beam by beam-beam interaction at each position. We have started an experimental study for the proof-of-principle of the new beam profile monitoring system. The paper presents the status quo of this beam profile monitor system development and the prospects to apply the system to the IFMIF beam line controls.
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.
ORNL, Oak Ridge, Tennessee
ORNL RAD, Oak Ridge, Tennessee
A laser wire system* has been developed in the Spallation Neutron Source (SNS) superconducting linac (SCL). The SNS laser wire system is the world largest of its kind with a capability of measuring profiles of an operational hydrogen ion (H-) beam at each of the 23 cryomodule stations along the SCL by using a single light source. Presently 9 laser wire stations have been commissioned that measure profiles of the H- beam at energy levels from 200 MeV to 1 GeV. The laser wire diagnostics has no moving parts inside the beam pipe and can be run parasitically on a neutron production H- beam. This talk reports our recent study of the laser wire profile measurement performance. Parasitic profile measurements have been conducted at multiple locations of SCL on an operational one-megawatt neutron production beam that SNS recently achieved as a new world record. We will describe experimental investigations of the laser wire system performance including the stability and repeatability of the measurement and the influence of the laser parameters. We will also discuss novel beam diagnostics capabilities at the SNS SCL by using the laser wire system.
* Liu et al., "Laser wire beam profile monitor in the SNS superconducting linac," Nucl. Instr. and Meth. A, to appear.
LANL, Los Alamos, New Mexico
Nearly all risks to future generations arising from long-term disposal of used LWR nuclear fuel are attributable to the transuranic elements and long-lived fission products, about 2% of its content. The transuranic elements of concern are plutonium, neptunium, americium, and curium. Long-lived (>100,000-year half-life) isotopes of iodine and technetium are also created by nuclear fission of uranium. If we can reduce or otherwise securely handle this 2% of the used fuel, the toxic nature of the remaining used fuel after a few centuries of cooling is below that of the natural uranium ore that was originally mined for nuclear fuel. Only a small fraction of the available energy in the fuel is extracted on a single pass and the majority of the 'problem wastes' could be burned in fast-neutron spectrum reactors or sub-critical accelerator driven transmuters. The goals of accelerator transmutation are some or all of the following: 1) to significantly reduce the impacts due to the minor actinides on the packing density and long-term radiotoxicity in the repository design, 2) preserve/use the energy-rich component of used nuclear fuel, and 3) reduce proliferation risk.
JINR, Dubna, Moscow Region
This presentation will describe the accelerators - basic facilities at JINR and briefly discuss research programs for applications and basic research, which are performed at these accelerators.
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.
KEK, Ibaraki
Japan has a long history of academia-industry collaboration on accelerator technology development. A recent example is superconducting cavity manufacture for the linear collider as well as a number of collaboration in superconducting magnets for circular colliders and physics experiments. Experience with Academia-industry Collaboration on Accelerator Projects in Japan and global Asia will be presented.
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken
KEK/JAEA, Ibaraki-Ken
A 3GeV Rapid-Cycling Synchrotron (RCS) in Japan Proton Accelerator Research Complex (J-PARC) has continuously provided more than 100kW proton beam to the Neutron target since October 2009. And we also successfully accelerated 300kW beam for one hour on December 10th by way of trial. We found some problems through these experiences. We report those problems and the residual dose in such high intensity operation.
ORNL, Oak Ridge, Tennessee
ORNL RAD, Oak Ridge, Tennessee
All stages of the SNS development require significant research and development work in the field of radiological shielding design to assure safety from a radiation-protection point of view for facility operation and to optimize accelerator and target performance. Here we present an overview of on-going shielding work and associated with it procedures and regulations. In the present time, the most of the shielding work is focused on the neutron beam lines and their instrument enclosures in order to commission and provide save operation in the future. This effort is performed according to the guidelines for shielding calculations of SNS neutron beam lines, which sets standards for the analyses and helps to prepare for the Instrument Readiness Review (IRR). The IRR ascertains that the instruments has been design, constructed, and installed to allow safe operation and maintenance. In addition, there is still support for the accelerator facility to redesign parts of the accelerator structures, to design shielding for removed components and test stands for accelerator structures, and for radiation protection analyses for evaluations of accelerator and target safety systems.
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
UMAN, Manchester
Fermilab, Batavia
Uppsala University, Uppsala
The 1.5TeV CLIC beams, with a total power of 14MW per beam, are disrupted at the interaction point due to the very strong beam- beam effect. The resulting spent beam products are transported to suitable dumps by the post-IP beam line, which generates beam losses and causes the production of secondary cascades towards the interaction region. In this paper the electromagnetic background at the IP are presented, which were calculated using biased Monte Carlo techniques. Also, a first estimate is made of neutron back-shine from the main beam dump.
TUB, Beijing
Since being introduced to accelerator physics, I have had the privilege to study and work with some of the best physicists on some of the most exciting projects. My first assignment was to simulate transition-crossing in RHIC in which a shocking 86% beam loss led to a redesign of its RF system which later earned me a Ph.D. Participation in the design, R&D, construction, and the commissioning of RHIC, not only was I introduced to the fascinating world of accelerator physics but was also trained as a physicist for accelerator projects. Since then, I have had the opportunity to work and lead teams of physicists and engineers on accelerator projects: US-LHC/AP at BNL, SNS/AP at ORNL, SNS ring, CSNS in China, and now CPHS at Tsinghua. The accelerator profession is uniquely rewarding in that ideas and dreams can be turned into reality through engineering projects, through which one experiences endless learning in physics, technology, teamwork and friendship. An example of enjoying the fun and friendship is the work on crystalline beams as a hobby for the past 18 years.
*Wei, Li, Sessler, Okamoto PRL73(94)3089; 80(98)2606
*Wei, Harrison XVI RCNP Osaka(97)
*Wei et al PAC99 2921
*Wei et al PAC01(01)319
*Wei RMP75(03)1383
*Wei et al NIMA600(09)10
*Wei et al PAC09
Air Liquide, Division Techniques Avancées, Sassenage
IPN, Orsay
Air Liquide, Sassenage
GANIL, Caen
The future superconducting Linear accelerator of the SPIRAL2 project at GANIL (France) will require a complete helium cryogenic system. Air Liquide DTA has been selected to provide around 1300W equivalent refrigeration power at 4.5K with mainly refrigeration load but also helium liquefaction rate and 60K thermal shields feed. The Helium cold box designed and manufactured by Air Liquide DTA will be derived from the standard HELIAL LF product to match the need for the SPIRAL2 project. The cryogenic system also includes a liquid Dewar, cryogenic lines and recovery system for liquefaction rate. Cryogenic distribution line and valves boxes for LINAC Cryomodules are designed and installed by GANIL.
ORNL, Oak Ridge, Tennessee
ORNL RAD, Oak Ridge, Tennessee
LANL, Los Alamos, New Mexico
BNL, Upton, Long Island, New York
The diamond stripper foils in use at the Spallation Neutron Source worked successfully with no failures until May 3, 2009, when we started experiencing a rash of foil failures after increasing the beam power to ~840 kW. The main contributions to foil failure are thought to be 1) convoy electrons, stripped from the incoming H− beam, that strike the foil bracket and may also reflect back from the electron catcher, and 2) vacuum breakdown from the charge developed on the foil by secondary electron emission. In this paper we will detail these and other failure mechanisms, and describe the improvements we have made to mitigate them.
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.
TU Darmstadt, Darmstadt
KVI, Groningen
The REX-ISOLDE facility at CERN delivers a great variety of radioactive ion beams with energies up to 3.0 MeV/u and therefore allows nuclear structure physics experiments far from stability. A crucial point for the experimentalist is the knowledge of possible unwanted beam contaminations, either from the bunching and charge-breeding procedure (residual gas ions) or directly from the ion-production process (isobaric contaminants). The sources of these contaminations will be discussed, as well as possible ways of elimination during the post-acceleration. Methods to analyse the beam composition in the relevant energy range will be presented with an emphasis on the experimental challenges in Gamma-spectroscopy experiments and data analysis.
KAPRA, Cheorwon
SNU, Seoul
University of Ulsan, Ulsan
The physics design of a Photo Fission Ion Source (PFIS) which will be used in a heavy ion accelerator is introduced. The design variables being considered are asymmetric magnetic field, cooling, neutron reflector and modulator (high density graphite), UCx target, bremsstrahlung power, microwave power and fission fragments (ions). Based on the design studied performed by using Monte Carlo codes and nuclear data, we will present the results, performance, optimization, ion distribution, bremsstrahlung power dependent radiation distribution, and temperature distributions. Finally we will conclude the feasibility of PFIS.
KEK, Ibaraki
The beam transport line between 3 GeV Rapid Cycling Synchrotron and Main Ring has a beam collimator system in order to improve the quality of injected beam in the main ring. The beam power deposited into the collimators is required to be increased for high intensity beam operation. The tolerance of existing radiation shield becomes insufficient, even though there is no heat problem. The gate-type shield system has been preparing in order to satisfy both the radiation shielding and feasibility of maintenance. The development of movable gate-type shield system is reported here, which fully covers more than 20 meters long collimator section.