Tokyo Institute of Technology/RIKEN, Tokyo
Tokyo Institute of Technology, Tokyo
Kyushu University, Fukuoka
JAEA, Ibaraki
BNL, Upton
We are investigating space charge dominated beam dynamics in a Radio Frequency Quadrupole (RFQ) linac. In some accelerator systems, desired ions with different charge state ions are simultaneously injected into an RFQ linac. To describe the evolution of the multi charge beam inside the RFQ, we did particle simulation by using Particle-Mesh (PM) method. Here the high-intensity carbon beam made up of C4+, C5+ and C6+ was applied to the simulation (C5+ was set to the designed ion). The space charge contributions to the transverse emittance growth and to the transverse and longitudinal particle motions are presented.
GSI, Darmstadt
HIT, Heidelberg
The Therapy Linac in Heidelberg (HIT) was successfully commissioned in 2006. Required beam parameters were reached except of the beam intensity. The achieved particle transmission for C4+ (design ion) is significantly lower than design. Particle losses are mainly observed in the RFQ. One critical point is the matching section of the RFQ electrodes - Input Radial Matcher (IRM). The original design requires too rigid and narrow beam Twiss-parameters at the RFQ entrance. Also the measured emittance is about twice higher compared to the design. Numerically and experimentally it was proven that the solenoid, used for the beam matching to the RFQ, is not able to provide for the necessary beam size and convergence. As it was shown by beam dynamics simulations using the code DYNAMION, a minor modification of the IRM allows for an improvement of the beam transmission (up to 50%). The proposed measure was realized for an advanced HIT-RFQ-layout, which is recently under test stage. The same modification is already proposed for the linac frontend at Italian Hadrontherapy Center (CNAO, Pavia).
GSI, Darmstadt
Funding: Work is partially supported by project VEGA 1/0129/09.
In the frame of the FAIR project irradiation test of superconducting magnet components was performed at GSI Darmstadt in May 2008. As a part of the experiment stainless steel samples were irradiated by 1 GeV/u 238U ions. In contrast to the previous experimental studies performed with thick cylindrical samples, the target was a thin plate irradiated at small angle. The target was constituted as a set of individual foils. This stacked-foil target configuration was foreseen for depth-profiling of residual activity. Gamma-ray spectroscopy was used as the main analytical technique. The isotopes with dominating contribution to the residual activity induced in the samples were identified and their contributions were quantified. Depth-profiling of the residual activity of all identified isotopes was performed by measurements of the individual target foils. The characteristic shape of the depth-profiles for the products of target activation and projectile fragments was found and described. Monte Carlo code FLUKA was used for simulations of the residual activity and for estimation of the number of ions delivered to the target and their distribution. The measured data are relevant for assessment of radiation situation at high-energy accelerators during the “hands-on” maintenance as well for assessment of the tolerable beam-losses.
ITEP, Moscow
INFN/LNL, Legnaro
Development of new materials for future energy facilities with higher operating efficiency is a challenging and crucial task. However, full-scale testing of radiation hardness of reactor materials is quite sophisticated and difficult as it requires long session of reactor irradiation; moreover, induced radioactivity considerably complicates further investigation. Ion beam irradiation does not have such a drawback, on the contrary, it has certain advantages. One of them is high speed of defect formation. Therefore, it provides a useful tool for modeling of different radiation damages. Improved understanding of material behavior under high dose irradiation will probably allow to simulate reactor irradiation close to real conditions and to make an adequate estimation of material radiation hardness. Since 2008 in ITEP the ion beam irradiation experiments are under development at the ITEP heavy ion RFQ HIP-1. The main objectives of this work are to study primary damage, cascade formation phenomena, phase stability and self-organization under irradiation. This research is carried out by means of tomographic atom probe and transmission electron microscopy. This linac provides accelerated beams of Cu2+, Fe2+, Cr2+ ions with current up to 10 mA and energy 101 keV/n. The first experiments with ion beam at the linac injector demonstrated promising results. The linac output beam line is now under upgrade. The results of beam extraction line adjustment for experiments with reactor materials are presented. The construction of controllable heated target is presented as well.
KIRAMS, Seoul
Design of conventional 4-vane/rod type of RFQ (Radio Frequency Quadrupole) for the heavy ion medical facility has been studied. The RFQ is capable of accelerating C4+ ions from an initial energy of 10 keV/u to 300 keV/u. In this work, all the design parameters have been optimized to achieve stable structure and compactness. The 3D electromagnetic field distribution and RF analysis were obtained by CST Microwave Studio and the field was used in TOUTATIS for beam simulation. This paper shows the determined physical and mechanical design parameters of RFQ.
TRIUMF, Vancouver
At the ISAC facility in TRIUMF radioactive ion beams (RIB) are produced using the ISOL method and post accelerated. The post accelerator chain consists of a radio frequency quadrupole (RFQ) injector followed by a drift tube linac (DTL) that accelerates the ions from 150 keV/u up to 1.8 MeV/u. A further stage of acceleration is achieved using a superconducting linac where the beam is injected using the DTL and the energy boosted with 20 MV of acceleration voltage (increased to 40MV by the end of 2009). The possibility of decelerating the beam maintaining good beam quality using the DTL is investigated based on experimenters request to reach energies lower than 150 keV/u. The beam dynamics simulation using the LANA code are compared with on line measurements. In this paper we will report the results of the investigation that aims to establish the lowest energy we can deliver in the post accelerator section of the ISAC facility.
GANIL, Caen
The Spiral 2 project uses normal conducting rebunchers to accelerate high intensity beams of protons, deuterons and heavier ions. All cavities work at 88 MHz, the beta is 0.04 and 3 rebunchers are located in the MEBT line, which accepts ions with A/q up to 6. The paper describes the RF design and the technological solutions proposed for an original 3-gap cavity, characterised by very large beam aperture (60 mm) and providing up to 120 kV of effective voltage.
IBA, Louvain-la-Neuve
JINR, Dubna
Carbon therapy is most effective method to treat the resistant tumors. A compact superconducting isochronous cyclotron C400 has been designed by IBA-JINR collaboration. This cyclotron will be used for radiotherapy with proton, helium and carbon ions. The 12C6+ and 4He2+ ions will be accelerated to the energy of 400 MeV/amu and will be extracted by electrostatic deflector, H2+ ions will be accelerated to the energy 265 MeV/amu and protons will be extracted by stripping. The magnet yoke has a diameter of 6.6 m, the total weight of the magnet is about 700 t. The designed magnetic field corresponds to 4.5 T in the hills and 2.45 T in the valleys. Superconducting coils will be enclosed in a cryostat; all other parts will be warm. Three external ion sources will be mounted on the switching magnet on the injection line located bellow of the cyclotron. The main parameters of the cyclotron, its design, the current status of development work on the cyclotron systems and simulations of beam dynamic will be presented.
INFN/BA, Bari
BINP, Novosibirsk
Bari University INFN/BA, Bari
The charge breeding technique is used for Radioactive Ion Beam (RIB) production in the Isotope Separation On Line (ISOL) method in order of optimizing the reacceleration of the radioactive elements produced by a primary beam in a thick target. In some experiments a continuous RIB of certain energy could be required. The EBIS based charge breeding device cannot reach a real CW operation because the high charge state ions produced are extracted by the same part where the 1+ ions are injected, that is, from the electron collector. In this paper, an hollow cathode e-gun for an EBIS in charge breeding operation has been presented. Furthermore, a preliminary system design to inject the 1+ ions from the cathode part will be also shown. In this way, the ions extraction system, placed in the electron beam collector, can be left only to extract the n+ ions, and then the CW operation, at least in principle, could be reached.
CIAE, Beijing
Guangxi University, Nanning
Funding: Work supported by the NSAF (National Nature Science Fundation- China Academy of Engineering Physics Fundation) No.10576040.
236U is a long-lived radioactive isotope with a half-life of 2.342(3) ×107 a, which produced principally by thermal neutron capture on 235U. 236U is potentially applied in geological research and nuclear safeguards. Accelerator mass spectrometry (AMS) is presently the most sensitive technique for the measurement of 236U. A method for AMS measurement of long-lived heavy ion 236U was developed at CIAE with the set up the AMS dedicated injector and the newly proposed 208Pb16O2- molecular ions for the simulation of 236U ion transport. A sensitivity of lower than 10-10 has been achieved for isotopic ratio 236U/238U in present work.