RIKEN, Wako, Saitama
In 2008, the RIKEN RI-Beam Factory (RIBF) succeeded in providing heavy ion beams of 48Ca and 238U with 170 particle-nano-ampere and 0.4 particle-nano-ampere, respectively, at an energy of 345 MeV/u. The transmission efficiency through the accelerator chain has been signifcantly improved owing to the continuous efforts paid since the first beam in 2006. From the operational point of view, however, the intensity of the uranium beam should be much increased. We have, therefore, constructed a superconducting ECR ion source which is capable of the microwave power of 28 GHz. In order to reduce the space-charge effects, the ion source was installed on the high-voltage terminal of the Cockcroft-Walton pre-injector, where the beam from the source will be directly injected into the heavy-ion linac by skipping the RFQ pre-injector. The test of the ion source on the platform has started recently with an existing microwave source of 18 GHz. This pre-injector will be available in October 2009. We will show further upgrade plan of constructing an alternative injector for the RIBF, consisting of the superconducting ECR ion source, an RFQ, and three DTL tanks. An RFQ linac, which has been originally developed for the ion-implantation application will be reused for the new injector. Modification of the RFQ as well as the design study of the DTL are under progress. The new injector, which will be ready in FY2010, aims at independent operation of the RIBF experiments and super-heavy element synthesis.
BARC, Mumbai
The 14 UD Pelletron Accelerator Facility at Mumbai has recently completed two decades of successful operation. The accelerator is mainly used for basic research in the fields of nuclear, atomic and condensed matter physics as well as material science. The application areas include accelerator mass spectrometry, production of track-etch membranes, radioisotopes production, radiation damage studies and secondary neutron production for cross section measurement etc. Over the years, a number of developmental activities have been carried out in-house that have helped in improving the overall performance and uptime of the accelerator and also made possible to initiate variety of application oriented programmes. Recently, a superconducting LINAC booster has been fully commissioned to provide beams up to A~60 region with E~5 MeV/A. As part of Facility augmentation program, it is planned to have an alternate injector system to the LINAC booster, consisting of 18 GHz superconducting ECR ion source, 75 MHz room temperature RFQ linac and superconducting low-beta resonator cavities. The development of an alternate injector will further enhance the utilization capability of LINAC by covering heavier mass range up to Uranium. The ECR source is being configured jointly with M/s Pantechnik, France, which will deliver a variety of ion beams with high charge states up to 238U34+. This paper will provide detailed presentation of developments being carried out at this facility.
BNL, Upton
Funding: Work supported under the auspices of the US Department of Energy and the National Aeronautics and Space Administration.
At Brookhaven National Laboratory, a high current Electron Beam Ion Source (EBIS) has been developed as part of a new preinjector that is under construction to replace the Tandem Van de Graaffs as the heavy ion preinjector for the RHIC and NASA experimental programs. This preinjector will produce milliampere-level currents of essentially any ion species, with q/A≥ 1/6, in short pulses, for injection into the Booster synchrotron. In order to produce the required intensities, this EBIS uses a 10A electron gun, and an electron collector designed to handle 300 kW of pulsed electron beam power. The EBIS trap region is 1.5 m long, inside a 5T, 2m long, 8” bore superconducting solenoid. The source is designed to switch ion species on a pulse-to-pulse basis, at a 5 Hz repetition rate. Singly-charged ions of the appropriate species, produced external to the EBIS, are injected into the trap and confined until the desired charge state is reached via stepwise ionization by the electron beam. Ions are then extracted and matched into an RFQ, followed by a short IH Linac, for acceleration to 2 MeV/A, prior to injection into the Booster synchrotron. An overview of the preinjector is presented, along with experimental results from the prototype EBIS, where all essential requirements have already been demonstrated. Design features and status of construction of the final high intensity EBIS is also be presented.
Goethe Universität Frankfurt/IAP, Frankfurt
MSU/NSCL, East Lansing
ECR and EBIS have become well-known ion sources for most heavy ion accelerator projects. The basic difference arises from the method, how energy is provided to create dense energetic electrons: An ECR uses microwave heating of a magnetically confined plasma, while in an EBIS the energy comes from a power supply to accelerate an electron beam and focus it to high density in a strong solenoidal magnetic field. Basically ECR sources are dc sources of heavy ions but the afterglow extraction also provides intense mA pulses in ms. In contrast to this EBIS sources provide an intense ion pulse in 1-100 μs and therefore find application in feeding synchrotrons. This determines most of the accelerator applications: ECR sources have very successfully extended the range (and life) of cyclotrons, while EBIS has found application at high energy facilities. For radioactive beam facilities, both kind of sources are in use. ECR sources in the trapping mode (ECRIT) perform the ionization (charge breeding) of high intensity primary beams, while EBIS can reach higher charge states at lower emittance, which provides an improved signal to noise ratio for rare isotopes.
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).
INFN/LNL, Legnaro
GSI, Darmstadt
CNAO, Milan
INFN/LNF, Frascati
INFN/LNS, Catania
The CNAO (Centro Nazionale di Adroterapia Oncologica), located in Pavia (Italy), is a dedicated clinical synchrotron facility for cancer therapy using high energy proton and Carbon beams. The 400 MeV/u synchrotron is injected by a 216.8 MHz 7 MeV/u linac composed by a low energy beam transport (fed by two ion sources), a 400 keV/u 4-rod type RFQ and a 20 MV IHDTL. The commissioning of the two ECRIS ion sources and the low-energy line was successfully completed at the end of January 2009 reaching the proper beam conditions for injection into the RFQ. After installation and conditioning, the RFQ was commissioned with beam by the GSI-CNAO-INFN team in March 2009. The beam tests results are presented and compared to the design parameters.
GSI, Darmstadt
The GSI linear accelerator UNILAC and the synchrotron SIS18 will feed the future accelerator facility FAIR (Facility for Antiproton and Ion Research) with heavy ion beams. Several hardware measures at the UNILAC are necessary to meet the FAIR requirement, implicating a beam intensity of 3.2·1011 of U28+-particles within an UNILAC macro pulse of 100μs length and defined emittance space at SIS18 injection. The stripper gas jet density was strongly increased to get the equilibrium charge state even for the heaviest ions. A procedure matching the 6-D-phase space for proper A lvarez DTL injection and increase of the transverse phase advance in the Alvarez accelerators reduces emittance growth. In front of SIS18 injection a new separator provides an immediate selection of the desired charge state after stripping and therefore reduces space charge induced emittance growth. The front-end of the high current injector includes several bottle necks. A compact solenoid channel is planned providing straight line injection into the 4-rod- RFQ. The RFQ will be equipped with new designed electrodes for increased acceptance and reduced emittance growth. The contribution gives an overview of end-to-end simulations, the different upgrade measures, the particular beam investigations, and the status of beam development satisfying FAIR requirements.
MSU/NSCL, East Lansing
GSI, Darmstadt
Goethe Universität Frankfurt/IAP, Frankfurt
Funding: Work supported by the BMBF.
The GSI accelerator facility provides highly charged ion beams up to U92+ at the energy of 400 MeV/u. These are cooled and decelerated down to 4 MeV/u in the Experimental Storage Ring. Within the Heavy Ion Trap facility HITRAP the ions are decelerated further down. The linear decelerator comprises a 108/216 MHz doubledrift- buncher, a 108 MHz-IH-structure, a spiral-type rebuncher, and an RFQ-decelerator with an integrated debuncher providing energy spread reduction. Finally the beam is injected with the energy of 6 keV/u into a Penning trap for final cooling. The decelerator is installed completely and first sections have been successfully commissioned. For commissioning of the individual sections different ion species, e.g. 64Ni28+, 20Ne10+, 197Au79+ were used. Each section was studied with comprehensive beam diagnostics to measure energy, emittance, intensity, transverse profiles, and bunch structure of the beam. The report gives an overview of the beam dynamics, the decelerator structures, and some results of the different commissioning runs.
INFN/LNL, Legnaro
PIAVE-ALPI is the INFN-LNL superconducting heavy ion linac, composed by an SRFQ (superconducting RFQ) section and three QWR sections for a total of 80 cavities installed and an equivalent voltage exceeding 70 MV. In the last years the SRFQ and the bulk niobium QWR came into routine operation, the medium energy QWR section was upgraded with a new Nb sputtered coating, ECR source was firstly improved by using water cooled plasma chamber and then replaced with a new one. The operation of the accelerator complex allowed acquiring a strong experience on many operational issues related to ECRIS, superconducting cavities and cryogenics, beam control and manipulation (with the new and higher accelerating gradient). The paper reports about operational experience, the present limitations and the future perspectives of the facility in view of the experimental campaign with the EU detector AGATA and of the use of PIAVE ALPI as RIB post-accelerator for SPES radioactive ion beam facility.
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.
CNAO, Milano
GSI, Darmstadt
INFN/LNF, Frascati
INFN/LNL, Legnaro
INFN/LNS, Catania
University of Pavia, Pavia
Politecnico di Milano, Milano
The Centro Nazionale di Adroterapia Oncologica (CNAO) is the Italian centre for deep hadrontherapy, namely an innovative type of radiotherapy using hadrons. The wide range of beam parameters (i.e., energy and intensity) at patient level together with the advantages of hadron-therapy with respect to traditional radio-therapy nourishes the hopes for more effective patient recovery. After the LEBT and the RFQ commissioning, the IH commissioning is now in progress. First patients are expected to be treated in 2010. The present paper summarizes and evaluates the Low Energy Beam Transfer (LEBT) line commissioning, which has been carried out between July 2008 and January 2009.
CNAO, Milano
INFN/LNF, Frascati
The Centro Nazionale di Adroterapia Oncologica (CNAO) is the first Italian center for deep hadrontherapy, namely an innovative type of oncological radiotherapy using hadrons. The CNAO machine installation is in progress and alternates with lines commissioning, started in the Summer 2008. The present paper reports about Beam Diagnostics (BD) choices, status and post-commissioning evaluation, as concerns the Low Energy Beam Transfer (LEBT) line monitors.