ANL, Argonne
Funding: This work was supported by the U.S. Department of Energy, Office of Nuclear Physics, under Contract No. DE-AC02-06CH11357.
Construction of the DOE Californium Rare Ion Breeder Upgrade (CARIBU) for the ATLAS facility is expected to be completed by the end of 2008 and commissioning should be well along by the time of the conference. The facility will use fission fragments from a 1 Ci 252Cf source, thermalized and collected into a low-energy particle beam by a helium gas catcher, mass analyzed by an isobar separator, and charge breed to higher charge states for acceleration in ATLAS. In addition, unaccelerated beams will be available for trap and laser probe studies. Expected yields of accelerated beams are up to ~5x105 (107 to traps) far-from-stability ions per second on target. The facility design and first results of beam acceleration using a weaker 80 mCi source will be presented in this paper and plans for installation of the 1 Ci source will be discussed.
INFN/LNL, Legnaro (PD)
The speaker will have expertise in the design, construction and operation of RFQs, both normal and superconducting. This talk will focus mostly on recent developments in RFQs for high power proton and deuteron beams, for both scientific and diverse purposes (e.g. Radioactive Nuclear Beam facilities, long-term irradiation tests of materials for Thermonuclear Fusion Reactors). The experience of the group at LNL in the field of cw RFQs originates from the realization of the PIAVE RFQ (superconducting 585 keV/u, heavy ion A/q<8.5) and the construction of the TRASCO RFQ (5 MeV, 30 mA protons). More recently within the collaboration between Europe and Japan for the construction of IFMIF-EVEDA in Rokkasho, the group at LNL is in charge of the design and construction of the RFQ (130 mA deuteron, 5 MeV). The physics design and the first construction test results will be ready for the PAC conference in 2009. In the same talk, the design approaches and experimental results of cw RFQs under development (for lower beam power) by other groups in Europe could be reviewed.
BNL, Upton, Long Island, New York
Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
A steering magnet is not a major component in a beam line, however it is usually needed in any real set up. Also it is hard to estimate the required field strength before the beam line construction, since the strength needed is determined by misalignnment errors of other devises. Sometimes it is difficult to find enough space to install steering magnets because of other constraints on the length of the beamline. We compare two extreme designs of steering magnets. The first one is very thin steering magnet design which occupies only 6 mm in length and can be additionally installed as needed. The other is realized by applying extra coil windings to a quadrupole magnet and does not consume any length. We will present both designs in details and will discuss pros and cons.
BNL, Upton, Long Island, New York
Kyushu University, Hakozaki
IAP, Frankfurt am Main
Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
A new heavy ion preinjector, consisting of an Electron Beam Ion Source (EBIS), an RFQ, and IH Linac, is under construction at Brookhaven National Laboratory. This preinjector will provide ions of any species at an energy of 2 MeV/u, resulting in increased capabilities for the Relativistic Heavy Ion Collider, and the NASA Space Radiation Laboratory programs. Initial operation of the EBIS and RFQ will be reported on, along with the status of the construction and installation of the remainder of the preinjector.
BNL, Upton, Long Island, New York
Kyushu University, Department of Applied Quantum Physics and Nuclear Engineering, Fukuoka
Department of Energy Sciences, Tokyo Institute of Technology, Yokohama
Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy. Work supported by RIKEN.
We have studied a laser ion source in Brookhaven National Laboratory since 2006. In November 2008, we had first beam through an RFQ and the measured current reached about 50 mA with carbon beam. The RFQ and ion source were originally commissioned in Japan and moved to BNL in 2006. We will report various acceleration test results at the conference.
BNL, Upton, Long Island, New York
The low energy (35 keV) and medium energy (750 keV) transport lines for (un)polarized H- have been reconfigured to reduce beam losses and the beam emittance out of the 200 MeV Linac. The medium energy line in the original layout was 7 m long, and had ten quadrupoles, two beam choppers, and three bunchers. The bunchers were necessary to keep the beam bunched at the entrance of the Linac. About 35% beam loss occurred, and the emittance growth was several fold. In the new layout, the 750 keV line is only 0.7 m long, with three quads and one buncher. To preserve beam polarization in the 35 keV line, the solenoid in front of the RFQ (35 keV to 750 keV) was replaced with an Einzel lens. To reduce the spin-precession in the LEBT, which may cause the depolarization, a 47.4 degree bend was removed and focusing solenoid in front of RFQ was replaced with an Einzel lens. We will present the experimental result of the upgrade.
Imperial College of Science and Technology, Department of Physics, London
JAI, Oxford
OXFORDphysics, Oxford, Oxon
For PAMELA project, the injection lay out for both protons as well as carbon 6+ ions is discussed. Injection system would consist of a 30 MeV cyclotron for protons and a chain of elements for carbon ions such as ECR ion source, bending magnets and focusing solenoids; RFQ, IH/CH structures and a striping foils. The charge particle simulation for different protons as well as carbon ions passing through the elements has been carried out with General Particle Tracer (GPT), software.
CEA, Gif-sur-Yvette
With the aim of producing an intense flux of 14 MeV neutrons, the International Fusion Materials Irradiation Facility (IFMIF) relies on two high power CW accelerator drivers, each delivering a 125 mA deuteron beam at 40 MeV to a common lithium target. The Engineering Validation and Engineering Design Activities (EVEDA) phase of IFMIF, which has been launched in the middle of 2007, has two major objectives: to produce the detailed design of the entire IFMIF facility and to build and test the key systems, in particular the prototype of a high-intensity CW deuteron accelerator (125 mA @ 9 MeV). The design of the IFMIF accelerator, as well as the design of the prototype to be installed in Rokkasho (Japan) are presented.
IAP, Frankfurt am Main
A short RFQ prototype was built for tests of high power RFQ structures. We will study thermal effects and determine critical points of the design. Simulations with CST Microwave Studio and first measurements were done. First results and the status of the project will be presented.
CNAO Foundation, Milan
INFN/LNF, Frascati (Roma)
The Centro Nazionale di Adroterapia Oncologica (National Center for Oncological Hadrontherapy, CNAO) is the Italian center for deep hadrontherapy. It will deliver treatments with active scanning both with proton and carbon ion beams. The accelerator complex is based on a 25 m diameter synchrotron capable to accelerate carbon ions up to 400 MeV/u and protons up to 250 MeV. Four treatment lines, in three treatment rooms, are foreseen in a first stage. In one of the three rooms a vertical and a horizontal fixed beam lines are provided, while in the other two rooms the treatment will be administered with horizontal beams only. The injection chain is positioned inside the synchrotron ring itself, to save space and to better exploit the two non-dispersive regions in the synchrotron. The injection chain is made by a 8 keV/u Low Energy Beam Transfer line (LEBT), a RFQ accelerating the beam to 400 keV/u, a LINAC to reach the injection energy of 7 MeV/u and a Medium Energy Beam Transfer line (MEBT) to transport the beam to the synchrotron. This report describes the design and the performances of the CNAO complex, and reports about the status of the commissioning of the machine.
TUB, Beijing
IHEP Beijing, Beijing
CIAE, Beijing
ANL, Argonne
KEK, Tsukuba
Funding: Supported by the “985 Project” of the Minister of Education of China, CAS Bairen Init. (KJCX2-YW-N22), CAS Overseas Outstanding Youth Program, and the National Natural Science Foundation (10628510).
During the past decades, large-scale national neutron sources are developed in Asia, Europe, and USA. Complementing such efforts, compact hadron beam complexes and neutron sources intended for universities and industrial institutes are proposed and established. Responding to the demands in China for multidisciplinary researches and applications using pulsed neutrons and protons, hadron therapy and radiography, and accelerator-driven sub-critical reactor systems (ADS) for nuclear waste transmutation, we here propose a compact yet expandable accelerator complex based on a proton source, a 3 MeV RFQ linac, and a 22 MeV DTL linac. A Be target with solid methane and room-temperature water moderators serve 6 neutron stations for imaging/radiography, irradiation, SANS, engineering powder diffraction, instrumentation, and therapy. The proton platform serves multiple stations for bio-applications, fuel cell and nano-applications, and space irradiation and detection. A rapid cycling synchrotron subsequently accelerates the beam to up to 300 MeV for proton therapy and radiography. Following the DTL linac with a superconducting RF linac and a sub-critical reactor offers an ADS test facility.
BNL, Upton, Long Island, New York
CEA, Gif-sur-Yvette
ESS-S, Lund
Fermilab, Batavia
CERN, Geneva
Funding: ESS-S Scandinavia Consortium
The conceptual design of the European Spallation Source-Scandinavia (ESS-S) is presented. The accelerator system baseline draws heavily on state-of-the-art mature technologies that are being employed in the CERN Linac4 and SPL projects, although advances with spoke resonator and sputtered superconducting cavities are also being evaluated for reliable performance. Irradiation damage due to proton beam losses is a key issue for linac and target components. Their optimized design is performed from an engineering perspective, using the last updated versions of mechanical design codes which were already qualified for irradiated components. Finally, future upgrades of power and intensity of the proton linac are considered, including the design optimization of the Target Station (proton/neutron convertor), with the possibility of increasing the average pulsed power deposition up to 7.5 MW. All possible upgrades will be taken into account for the final design review, in the frame of the costs and constraints given with the site decision.
ORNL RAD, Oak Ridge, Tennessee
ORNL, Oak Ridge, Tennessee
Funding: SNS is managed by UT-Battelle, LLC, under contract DE-AC05-00OR22725 for the U.S. Department of Energy.
Over the past year the performance of the LBNL H- source has been improved to routinely produce 36 mA when averaged over 0.7 ms long pulses at 60 Hz, measured at the RFQ output of the Spallation Neutron Source accelerator. This is up from 25-30 mA during early 2008, and up from {10}-20 mA during 2007. Some of the recent gain was achieved with refined conditioning and cesiation procedures, which now yield peak performance within 8 hours of starting a source change. The ~10 mg released Cs is sufficient for 3 weeks of operation without significant degradation. Another recent gain comes from the elevated Cs collar temperature, which was gradually implemented to probe its impact on the performance lifetime. In addition, load resistors improve the voltage stability of the electron dump and the lenses, which now can be more finely tuned. The achieved gain allowed for lowering the RF power to ~50 kW for improved reliability. A beam current of 38 mA is required at SNS for producing neutrons with a proton beam power of 1.4 MW. In one case, after 12 days of 4% duty factor operation, 56 mA were demonstrated with 60 kW of RF power. This is close to the 59 mA required for 3 MW operations.
IHEP Beijing, Beijing
PKU/IHIP, Beijing
CIAE, Beijing
A high-duty factor proton RFQ accelerator has been constructed at IHEP, Beijing for the basic study of Accelerator Driven Subcritical System. The ADS basic study is supported by a national program for nuclear waste transmutation which is regarded essential for the rapid development of nuclear power plants in China. In the initial commissioning of the 3.5MeV RFQ with an ECR ion source showed a nice performance with a transmission rate about 93% with an output beam of 46mA. The 352MHz RFQ is design for CW operation with the RF power source from LEP-II of CERN. This paper presents the beam commissioning and recent progress in high-duty factor operation from 7% to 15%.
GSI, Darmstadt
NSCL, East Lansing, Michigan
IAP, Frankfurt am Main
Funding: European Commission; contract number HPRI-CT-2001-50036 (HITRAP) German Ministry for Education and Research (BMBF; contract number 06 FY160I
Deceleration of heavy, highly charged ions from the ion storage ring ESR of the GSI accelerator facility with an rf-linear decelerator will provide ions up to bare uranium almost at rest for cutting edge experiments in atomic and nuclear physics. For this unique approach the beam has to be prepared well by electron cooling in the ESR to account for a 26 time increase of the transverse emittance during the following deceleration. An interdigital H-type (IH) structure and a radio-frequency quadrupole (RFQ) structure are operated in inverse to decelerate first from 4 MeV/u to 0.5 MeV/u and then to 6 keV/u. The quasi-continuous beam from the ESR is adapted, by using a double drift buncher, to match the longitudinal acceptance of the IH. Downstream from the IH-structure the 0.5 MeV/u beam is then fit with a spiral re-buncher to the RFQ, which finally decelerates the ions to 6 keV/u. First commissioning beam times have shown that the bunching works well and ions have been decelerated to 0.5 MeV/u in the IH structure. Extensive measurements of transversal emittance before and after deceleration can now be compared to beam dynamics calculations.
IHEP Beijing, Beijing
CSNS accelerator mainly consists of an H- linac and a proton rapid cycling synchrotron. It is designed to accelerate proton beam pulses to 1.6 GeV kinetic energy at 25 Hz repetition rate, striking a solid metal target to produce spallation neutrons. The accelerator is designed to deliver a beam power of 120 kW with the upgrade capability up to 500 kW, The CSNS accelerator is the first large-scale, high-power accelerator project to be constructed in China and thus we are facing a lot of challenges in some key technologies. A series of R&D for major prototypes have being conducted since 2006, including an H- ion source, DTL tank, RF power supply for the linac, injection/extraction magnets and its pulse power supplies, dipole and quadrupole prototype magnets in the ring and its power supplies, ferrite-loaded RF prototype cavity, ceramic vacuum chamber, control and some beam diagnostics. This paper will briefly introduce the design and R&D status of the CSNS accelerator.
CEA, Gif-sur-Yvette
INFN/LNL, Legnaro (PD)
During the EVEDA (Engineering Validation and Engineering Design Activities) phase of the IFMIF (International Fusion Materials Irradiation Facility) project, a 125 mA/9 MeV accelerator prototype will be built, tested and operated in Rokkasho-Mura (Japan). The injector section of this accelerator is composed by an ECR source, delivering a 140 mA deuteron beam at 100 keV, and a low energy beam transport (LEBT) line required to match the beam for the RFQ injection. The proposed design for the LEBT is based on a dual solenoids focusing scheme. In order to takes into account the space charge compensation of the beam induced by the ionisation of the residual gas, a 3D particle-in-cell code (SOLMAXP) has been developed for the beam dynamics calculations. The LEBT parameters have been optimized in order to maximize the beam transmission through the RFQ. The final LEBT design, as well as the simulation results, are presented.
CEA, Gif-sur-Yvette
INFN/LNL, Legnaro (PD)
CIEMAT, Madrid
The two IFMIF (International Fusion Materials Irradiation Facility) accelerators will each have to deliver 5 MW of deuteron beam at 40 MeV. To validate the conceptual design, a prototype, consisting of one 9 MeV accelerator called EVEDA (Engineering Validation and Engineering Design Activity), is being constructed. Beam dynamics studies are entering the final phase for the whole EVEDA and for the accelerating part of IFMIF. The challenging point is to be able to reconcile the very strong beam power and the hands-on maintenance constraint. At energies up to 5 MeV, difficulties are to reach the requested intensity under a very strong space charge / compensation regime. Over 5 MeV, difficulties are to make sure that beam losses can be maintained below 10-6 of the beam intensity. This paper will report the strategies and choices adopted in the optics design and the beam measurement proposal.
IAP, Frankfurt am Main
Funding: * Work supported by BMBF contr. No. 06F134I & EU contr. No. EFDA/99-507ERB5005CT990061
The International Fusion Materials Irradiation Facility (IFMIF) is looking for an efficient drift-tube linac (DTL) which can accelerate a 125mA, CW deuteron beam from 5MeV to 40MeV with a high beam quality and nearly no beam loss. Taking advantages of the KONUS dynamics concept and the H-type structure, a compact DTL design has been realized by IAP, Frankfurt University, with satisfying performances. Including simulated errors, the feasibility of the IAP scheme has been carefully checked as well.
IAP, Frankfurt am Main
For the development of high energy and high duty cycle RFQs accurate particle dynamic simulation tools are important optimize designs especially in high current applications. To describe the external fields in RFQs the Poisson equation has to be solved taking the boundary conditions into account. In the newly developed subroutines this is done by using a finite difference method on a grid. The results of this improvement are shown and compared to the old two term and multipol expansions.
Institute of High Energy Physics, CAS, Bejing
IHEP Beijing, Beijing
A high current proton RFQ accelerator has been constructed in China for the basic study of Accelerator Driven Subcritical System. A new beam line will be set up for the 3.54MeV, 50mA proton beam from the RFQ in order to study beam halo phenomenon. Therefore, 18 wire scanners consist of a thin carbon wire and two scrapers will be installed on the beam line to traverse the entire beam cross-section. So we can experimentally study the beam loss and beam halo. Some simulations results of the heat on the devices by using finite element method software–ANSYS are presented. The electronics interface will also be discussed.
BNL, Upton, Long Island, New York
Kyushu University, Department of Applied Quantum Physics and Nuclear Engineering, Fukuoka
IAP, Frankfurt am Main
Department of Energy Sciences, Tokyo Institute of Technology, Yokohama
Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
A new 4 rod RFQ fabricated by IAP, Frankfurt, is being commissioned at Brookhaven National Laboratory. The RFQ will accelerate intense heavy ion beams provided by an Electron Beam Ion Source (EBIS) up to 300 keV/u. The RFQ will accelerate a range of Q/M from 1 to 1/6, and the accelerated beam will be finally delivered to RHIC and NSRL. The first beam test is planned to use beams from the BNL Test EBIS. The detailed test results will be presented.
Fermilab, Batavia
Funding: Operated by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the United States Department of Energy.
The present FNAL Linac H- injector has been operational since 1978 and consists of a magnetron H- source and a 750-keV Cockcroft-Walton Accelerator. The proposed upgrade to this injector is to replace the present magnetron source having a rectangular aperture with a circular aperture, and to replace the Cockcroft-Walton with a 200-MHz RFQ. Operational experience at other laboratories has shown that the upgraded source and RFQ will be more reliable and require less manpower than the present system.
Fermilab, Batavia
Funding: Work performed by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the United States Department of Energy.
The High Intensity Neutrino Source (HINS) linac R&D program at Fermilab is constructing a first-of-a-kind superconducting H- linac. The machine will demonstrate acceleration of high intensity beam using superconducting spoke cavities, solenoidal focusing optics throughout for control of halo growth, and operation of many cavities from a single high power rf source for acceleration of non-relativistic particles. The ion source and RFQ are operational with beam and the 10 MeV room temperature cavity section is being assembled. Superconducting spoke cavity testing is proceeding. The overall status and outlook of the HINS program is presented.
GSI, Darmstadt
The GSI UNILAC serving as a high duty factor heavy ion linac is in operation since nearly 35 years. An upgrade program dedicated to FAIR will be finished until 2011. For the FAIR project the synchrotron SIS 18 has to be filled up to the space charge limit. After re-commissioning of the UNILAC the replacement of the main DTL is foreseen. A new 4 MV/m 108 MHz IH-LINAC provides a high intensity 5 MeV/u U4+-beam. The existing gas stripper section is reused to perform a beam intensity of 24 emA in charge state 42+. The existing UNLAC-tunnel may house a high efficient linac structure. A superconducting or normal conducting 324 MHz-CH-linac (crossbar H-structure) is under consideration as well as rf-resonators of half wave or quarter wave type. The new high energy linac should be able to boost the beam energy up to 30 MeV/u. A further upgrade option is a second 100 m-linac (324 MHz) to enhance the beam energy to up to 100 MeV/u (U41+), sufficient to feed the FAIR 100 Tm synchrotron in direct line. The paper will report on the ongoing conceptual layout of a new UNILAC-concept.
IAP, Frankfurt am Main
The goal of the Frankfurt Funneling Experiment is to multiply beam currents by merging two low energy ion beams. In an ideal case this would be done without any emittance growth. Our setup consists of two ion sources, a Two-Beam-RFQ accelerator and a multi cell deflector which bends the beams to one common beam axis. Current work is the design of a new beam transport system between RFQ accelerator and deflector. With extended RFQ-electrodes the drift between the Two-Beam-RFQ and the rf-deflector will be minimized and therefor unwanted emittance growth prohibited. First rf measurements with a scaled experiment will be presented.
IAP, Frankfurt am Main
Funneling is a method to increase low energy beam currents in multiple stages. The Frankfurt Funneling Experiment is a model of such a stage. The experiment is built up of two ion sources with a electrostatic lens systems, a Two-Beam RFQ accelerator, a funneling deflector and a beam diagnostic system. The two beams are bunched and accelerated in a Two-Beam RFQ and the last parts of the RFQ electrodes achieve a 3d focus at the crossing point of the two beam axis. A funneling deflector combines the bunches to a common beam axis. The optimized ion sources are adapted to the front end bunching section. Recent funneling measurements with the one-gap and the multi-gap deflector will be presented.
IAP, Frankfurt am Main
GSI, Darmstadt
A new CW-RFQ will be built for the upgrade of the HLI (High Charge State Injector) of GSI for operating with a 28 GHz-ECR-Ion source and simultaneous increase of the beam duty cycle from 25% to 100 %. The new HLI 4-rod RFQ will accelerate charged ions from 4 keV/u to 300 keV/u for the injection into the IH-structure The design had been optimized to get a rather short structure with LRFQ=2m to match the available RF-power of max. 60 kW in cw. High beam transmission, a small energy spread and small transverse emittance growth and good input matching were design goals. Properties of this CW-RFQ and status of project will be presented.
INFN- Sez. di Padova, Padova
INFN/LNL, Legnaro (PD)
Consorzio RFX, Associazione Euratom-ENEA sulla Fusione, Padova
The IFMIF-EVEDA RFQ is a 9.8 m long cavity, whose working frequency is equal to 175 MHz. In the base line design the accelerator tank is composed of 9 modules flanged together and a pattern of lateral CF100 flanges allows to host the dummy tuners and the couplers, and a pattern of CF 150 flanges the apertures for vacuum pumping manifolds as well. The construction procedure of each module foresees the horizontal brazing of four half module length electrodes and then the vertical brazing of two brazed assembly. The progresses in the design and engineering phase, as well the description of all the fabrication phases are reported.
Imperial College of Science and Technology, Department of Physics, London
The PAMELA 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. An integrated RFQ design process has been developed using various software packages to take the design parameters for the RFQ, convert this automatically to a CAD model using Autodesk Inventor, and calculate the electric field map for the CAD model using CST EM STUDIO. 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. Initial particle tracking simulations based on modifying the field map from the Front-End Test Stand (FETS) RFQ design have determined the best operating frequency for the PAMELA RFQ to be close to 200 MHz and the length approximately 2.3 m. The status of the injector design with an emphasis on the RFQ will be presented, together with the results of the particle tracking.
Imperial College of Science and Technology, Department of Physics, London
STFC/RAL, Chilton, Didcot, Oxon
A 4m-long, 324MHz four-vane RFQ, consisting of four coupled sections, is currently being designed for the Front End Test Stand (FETS) at RAL in the UK. Previous beam dynamics simulations, based on field maps produced with a field approximation code, provide a baseline for the new design. A novel design method is presented that combines the CAD and electromagnetic modelling of both the RFQ tank and the vane modulations with more sophisticated beam dynamics simulations using the General Particle Tracer code (GPT). This approach allows the full integration of the optimisation of the RFQ, based on beam dynamics simulations using a 3D EM-field map of the CAD model, with the design and manufacture of the RFQ vane modulations and RFQ tank. The design process within the Autodesk Inventor CAD software is outlined and details of the EM modelling of the RFQ in CST EM Studio are given. Results of beam dynamics simulations in GPT are presented and compared to previous results with field approximation codes. Finally, possible methods of manufacture based on this design process are discussed.
NSCL, East Lansing, Michigan
Funding: This work is supported by the U.S. Department of Energy
The superconducting (SC) driver linac developed for the proposed Facility for Rare Isotope Beams (FRIB) at Michigan State University (MSU) will be able to accelerate stable beams of heavy ions to > 200 MeV/u with beam powers up to 400 kW. The driver linac front-end will include ECR ion sources, a bunching system for multi-charge state beams and a radio frequency quadrupole (RFQ). The superconducting linac will have a base frequency of 80.5 MHz primarily using SC cavities and cryomodules developed for the Rare Isotope Accelerator (RIA), the FRIB predecessor. A charge-stripping chicane and multiple-charge state acceleration will be used for the heavier ions in the driver linac. A beam delivery system will transport beam to the in-flight particle fragmentation target station. The paper will discuss recent progress in the accelerator system design for the superconducting driver linac.
PKU/IHIP, Beijing
Funding: supported by NSFC (19775009)
A trapezoidal IH-RFQ (T-IH-RFQ) is being built to accelerate 14C^+ from 40 keV to 500 keV, motivated by RFQ based 14C AMS application at Peking University. The last design of beam dynamics and the optimized results of RF structure will be presented in this paper. The length of the cavity is about 1.1m operating at {10}4MHz, with a designed transmission efficiency of more than 97%. A special feature is that the RFQ output beam energy spread is as low as 0.6% approached by the method of internal discrete bunching. On the other hand, the new RF cavity structure T-IH-RFQ was proposed for the beam dynamics design, which has higher resonant frequency than traditional four rods RFQ and IH-RFQ at the same transverse dimension. Microwave Studio (MWS) simulations have been performed to study the field distribution and power consumption characteristic of this T-IH-RFQ. The specific shunt impedance and the quality factor have been optimized. Those details will be given.
Soreq NRC, Yavne
ACCEL, Bergisch Gladbach
The Soreq Applied Research Accelerator Facility, SARAF, is currently under construction at Soreq NRC. SARAF is based on a continuous wave (CW), proton/deuteron RF superconducting linear accelerator with variable energy (540 MeV) and current (0.04-2 mA). SARAF is designed to enable hands-on maintenance, which implies beam loss below 10-5 for the entire accelerator. Phase I of SARAF consists of a 20 keV/u ECR ion source, a low energy beam transport section, a 4-rod RFQ, a medium energy (1.5 MeV/u) transport section, a superconducting module housing 6 half-wave resonators and 3 superconducting solenoids, a diagnostic plate and a beam dump. Phase II will include 5 additional superconducting modules. The ECR source is in routine operation since 2006, the RFQ is in routine operation with protons since 2008 and has been further operated with molecular hydrogen and deuterons. The superconducting module is being operated and characterized with protons. Phase I commissioning results, their comparison to beam dynamics simulations and Phase II plans will be presented.
DAE/VECC, Calcutta
UGC DAE CSR, Kolkata
An ISOL post-accelerator type of Rare Ion Beam (RIB) facility is being developed at our centre. The facility will use light ion beams from the K=130 cyclotron for producing RIBs using suitable thick targets. Also, development of an electron LINAC has been initiated with an eye to produce RIBs using the photo-fission route. The RIBs will be ionized, mass separated and the RIB of interest will be accelerated using a four rod Radio Frequency Quadrupole from 1.7 to 98 keV/u. The posts, vanes and base plate of the RFQ have been machined from OFC copper and the cavity is made from steel with its inner surface plated with copper. Oxygen beam of charge state 5+ has already been accelerated with an efficiency of around 90% through the RFQ. The first IH LINAC will accelerate RIBs up to about 186 keV/u. The octagonal shape LINAC cavity is made from explosively bonded copper cladded steel. Low power tests of the LINAC is encouraging - the beam test is scheduled for January 2009 and the results of which will be reported. The R&D efforts in various areas of this project will be discussed in this paper. Special emphasis will be given to the development of the RFQ and LINAC.
NSCL, East Lansing, Michigan
The Facility for Rare Isotope Beams (FRIB) will provide intense beams of short-lived isotopes for fundamental research in nuclear structure and nuclear astrophysics. Operation of the facility requires intense uranium primary beams. At the present time acceleration of two simultaneous charge states of uranium from a single ion source is needed to achieve the required intensity. Three schemes are considered for funneling the beams from two sources as an alternate solution. One is the traveling wave RF kicker for merging of bunched beams extracted from ECR ion sources. Another one implements the idea of utilizing an RFQ for beam merging*, which can be used after preliminary acceleration of both beams. The third approach assumes usage of a conventional standing-wave RF kicker. Parameters of all three schemes are compared and analyzed.
*R.H.Stokes and G.N.Minerbo, AIP Conference Proceedings 139 (1985), p.79.
PKU/IHIP, Beijing
Funding: work supported by NSFC(10805003,10855001)
The beam commissioning of Separated Function RFQ (SFRFQ) accelerator, which can gain high accelerating efficiency and enough focusing strength for low energy high current beam, is presented. In order to demonstrate the feasibilities of this novel accelerator, a prototype cavity was designed and constructed. The O+ beam was accelerated from 1MeV to 1.6MeV by SFRFQ cavity. A triplet was constructed for the transverse beam matching between the 1MeV ISR-RFQ 1000 and SFRFQ. A capacitance frequency tuning system and RF phase shifter were used to keep SFRFQ cavity working at the same frequency of ISR RFQ at the right phase. The whole RFQ accelerator system and the preliminary beam test results are presented in this paper.