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 (5-40 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 an ECR ion source, a LEBT section, a 4-rod RFQ, a MEBT 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 has been in routine operation since 2006, the RFQ has been operated with ions and is currently under characterization. The superconducting module rf performance is being characterized off the beam line. Phase I commissioning results, their comparison to beam dynamics simulations and Phase II plans will be presented.
Fermilab, Batavia
ANL, Argonne
IUCF, Bloomington, Indiana
Funding: Fermilab is operated 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 aims to construct and operate a first-of-a-kind, 60 MeV, superconducting H- linac. The machine will demonstrate acceleration of high intensity beam using superconducting spoke cavities from 10 MeV, solenoidal focusing optics throughout for axially-symmetric beam to control halo growth, and operation of many cavities from a single high power rf source for acceleration of non-relativistic particles.
IAP, Frankfurt am Main
The Frankfurter neutron source at Stern-Gerlach-Zentrum (SGZ) uses a proton injector as a driver for the 7Li(p,n) neutron production. A volume type ion source will deliver a 100 keV, 200 mA proton beam continuously. It is intended to use a LEBT section consisting of four solenoids to transport the beam and to match it into the acceptance of the RFQ. A chopper system between solenoid 2 and 3 will provide beam pulses with a length of about 100 ns with a repetition rate of 250 kHz. The RFQ and the following IH drift tube LINAC will be coupled together to achieve an efficiency beam acceleration. Furthermore only one power amplifier will be needed to provide the rf power for both accelerator stages. The Mobley type bunch compressor will merge 7 micro-bunches formed in the accelerator module to one single 1ns bunch with an estimated peak current of about 8.6 A. A rebuncher will provide the post acceleration at a final beam energy adjustable between 1.8 and 2.4 MeV. The whole injector suffers from the high beam intensity and therefore high space charge forces. It will gives the opportunity to develop new accelerator concepts and beam diagnostic technics.
KAERI, Daejon
A 20 MeV proton accelerator, which consists of a 50 keV injector, a 3 MeV RFQ and a 20 MeV DTL, has been tested by Proton Engineering Frontier Project (PEFP) at Korea Atomic Energy Research Institute (KAERI. The operation conditions are 20 MeV, 20 mA peak current, 50 μs pulse length with a 1 Hz repetition rate due to the limited radiation shielding. The accelerator was tuned to reach to the above operating conditions. Moreover, an irradiation facility with external beam has been installed to supply the proton beam for the user and irradiation test. In this paper, we present results from tuning operation and the irradiation tests.
CERN, Geneva
Linac4 is a 160 MeV, 40 mA H- linear accelerator which will be the source of particles for all CERN proton accelerators from 2013. Its construction has started in 2008, as part of a program for the progressive replacement or upgrade of the LHC injectors during the next decade. Linac4 will initially inject into the PS Booster and at a later stage into a 4 GeV Superconducting Proton Linac (SPL), which could ultimately be upgraded to high duty cycle operation. For this reason accelerating structures, rf hardware and shielding of Linac4 are dimensioned for higher duty from the initial phase. Linac4 is normal-conducting, 80 m long and consists of an rf volume ion source, an RFQ, a beam chopping section and a cascade of three different types of 352 MHz accelerating structures. Its main design requirements are high reliability, high beam brightness and low beam loss. The accelerator will be housed in an underground tunnel on the CERN site, which can eventually be extended to the SPL, with equipment installed in a surface building above. The main parameters, the status of the main components, the planning, the project organisation and the civil engineering infrastructure are presented.
Fermilab, Batavia
TRIUMF, Vancouver
Muons, Inc, Batavia
JLAB, Newport News, Virginia
Modern technology allows us to consider operating an 8 GeV Linac in a cw mode to accelerate a high-current H- beam. By using appropriate accumulation rings, the linac could provide simultaneous beams for direct neutrino production, neutrino factories, fixed target experiments, and muon colliders. Several other unique accelerator applications could also be served and improved by the same continuous beam, including studies of energy production and nuclear waste reduction by transmutation, rare muon decay searches, and muon catalyzed fusion. The trade-offs between cw operation compared to pulsed operation that are considered include the maximum rf gradient and corresponding linac length or energy, the rf frequency, rf peak power and coupler requirements, and refrigeration. Methods for accumulating the beam from a cw linac to serve the special needs of the potential future Fermilab programs mentioned above are considered. In this paper we also examine the use of a cyclotron as a source of high current beams to reduce the cost and complexity of the linac front end.
LANL, Los Alamos, New Mexico
Funding: U. S. Department of Energy, National Nuclear Security Administration, Contract No. DE-AC52-06NA25396
The Los Alamos Neutron Science Center (LANSCE) continues to be a signature experimental science facility at Los Alamos National Laboratory (LANL). The 800 MeV linear proton accelerator provides multiplexed beams to five unique target stations to produce medical radioisotopes, ultra-cold neutrons, thermal and high-energy neutrons for material and nuclear science, and to conduct proton radiography of dynamic events. Recent operating experience will be reviewed and the role of an enhanced LANSCE facility in LANL's new signature facility initiative, Matter and Radiation in Extremes (MaRIE) will be discussed.
LA-UR-08-03581
NSC/KIPT, Kharkov
Experiments with heavy ion beams accelerated to an energy of 8.5 MeV/u as well as the work at developing new methods of acceleration and upgrading of accelerating structures are carried on at the Kharkov heavy-ion linear accelerator MILAC. The accelerating H-type structure with drift tubes of interdigital type (IH-structure) has been introduced in the main section and two pre-stripping sections of the MILAC accelerator. New original methods of tuning developed at MILAC have enabled the formation of uniform distribution of the accelerating field along the whole length of the accelerating structure. The introduction of IH accelerating structures of various modifications at the MILAC accelerator substantially extends the scientific and applied ranges of research. It involves experimental studies with heavy ions beams for production of track-etched membranes, generation of unique radionuclides, developments of proton and ion therapy, studies of radiation characteristics of constructional materials for nuclear engineering, investigations into the processes of fusion-fission of superheavy nuclei, and many other problems of nuclear physics.
CERN, Geneva
As part of the upgrade of the LHC injector complex at CERN, the construction of a 4 GeV Superconducting Proton Linac (the SPL, in fact an H- accelerator) is planned to begin in 2012. Depending upon physics requests, it should be upgradeable to 5 GeV and multi-MW beam power at a later stage. The construction of Linac4, its low energy front end, has started at the beginning of 2008. A full project proposal with a cost estimate for the low power version of the SPL aimed at improving LHC performance has to be ready for mid-2011. As a first step towards that goal, essential machine parameters like rf frequency, cooling temperature and beam current have recently been revisited and plans have been drawn for designing and testing critical components. The SPL parameters are reviewed in the context of the CERN plans for upgrading the LHC injectors, and the foreseen developments during the next years are described.
Kyoto ICR, Uji, Kyoto
JAEA/Kansai, Kizu-machi Souraku-gun Kyoto-fu
JAEA, Ibaraki-ken
NIRS, Chiba-shi
Funding: This work is supported by Advanced Compact Accelerator project by MEXT of Japanese Government and 21COE of Kyoto University, Center for Diversity and Universality in Physics.
By the phase rotation with the use of rf electric fields created by two gap resonator synchronous to a pulse laser, the energy spread of the laser-produced ions can be reduced*. In addition, owing to the curved structure of the electric field line in the gaps of the phase rotator, radial focusing effect is found also to exist. In order to extend the applicable energy of the phase rotation to the region where such laser produced protons can be directly applied for cancer therapy, multi-gap resonator with higher frequency has been proposed. By controlling the relative phases between the pulse laser and the electric fields in the gaps of phase rotator, we can create peaks in the energy spectrum simultaneously focusing in the radial direction.
* Japanese Journal of Applied Physics (Express Letter), 46 (2007) L717-L720
NIIEFA, St. Petersburg
AN Krylov SRI, St. Petersburg
Funding: Rosatom corp.
There are examined prospects and challengers associated with the development of low-energy electronuclear power plant eliminating any possibility of uncontrolled chain fission reaction through fission in subcritical reactor with an additional neutron source. The neutron source is anticipated to be a heavy-element target irradiated with a beam of protons accelerated to several hundreds of mega-electron-volts. The intensity of external neutron source for an electronuclear reactor rated under 200-400 MW may be much less than for greater ones, and that allows reducing accelerator performances to limits that are already run in the world industry. Potential applications of such electronuclear plants include municipal, industrial and other electricity, and heat supply utilities in remote areas. The same engineering philosophy may be used on solving of the nuclear waste transmutation problem.
IIT, Chicago, Illinois
Illinois Institute of Technology, Chicago, Illinois
LBNL, Berkeley, California
Funding: This work was partially supported by the Office of Science, U. S. Department of Energy, under Contract No. DE-AC02-05CH11231.
A key unanswered question in particle physics is why the universe consists only of matter. It is believed that CP violation in the lepton sector is the answer. The best tool to find this is a muon-based Neutrino Factory. Muons can also be used for an energy-frontier collider that would fit on an existing laboratory site. Since muons are produced as a tertiary beam, their phase space and energy spread are large and must be reduced (cooled) to create a usable beam. Ionization cooling, comprising momentum loss in material followed by rf reacceleration, is the only suitable technique. A cooling channel is merely a linac with absorbing material in the beam path. To demonstrate an understanding of the physics and technology issues, MICE will test a section of cooling channel exposed to a muon beam derived from the ISIS synchrotron at RAL. The muon beam line is now installed and commissioning is under way. Fabrication of cooling channel components and the required detector systems has begun and will be described. A successful demonstration will go a long way toward proving the value of muon beams for future accelerator-based particle physics experiments.
INFN/LNL, Legnaro, Padova
Soreq NRC, Yavne
IPN, Orsay
CEA, Gif-sur-Yvette
TRIUMF, Vancouver
Funding: We acknowledge the financial support of the European Community under the FP6 "Research Infrastructure Action-Structuring the European Research Area" EURISOL DS Project Contract No. 515768 RIDS.
A 1 GeV, 5 mA cw superconducting proton/H- linac, with the capability of supplying cw primary beam to up to four targets simultaneously by means of a new beam splitting scheme, is under study in the framework of the EURISOL DS project which aims to produce an engineering-oriented design of a next generation European Radioactive beam facility. The EURISOL driver accelerator would be able to accelerate also a 100 muA 3He beam up to 2 GeV, and a 5 mA deuteron beam up to 200 MeV. The linac characteristics and the status of the beam dynamics studies will be presented.
NIIEFA, St. Petersburg
Saint-Petersburg State University, Saint-Petersburg
AN Krylov SRI, St. Petersburg
Funding: Rosatom corp.
We present results of calculations of the neutron generation processes in metal targets induced by protons with energies up to 1 GeV using GEANT4 framework. Results on the neutron yield in large targets and neutron generation as a function of target's dimensions are presented. Energy deposit in the target is also given. The obtained results are to be used for multiplying blanket ADS target design.
CERN, Geneva
In its June 2007 session the CERN Council has approved the White Paper, which includes construction of a 160 MeV H- linear accelerator called LINAC4, and the study of a 4 GeV Superconducting Proton Linac (SPL). LINAC4 will initially replace LINAC2 as the injector to the PS Booster, improving its performance up to the levels required for producing the ultimate LHC luminosity. In a later stage, LINAC4 is intended to become the front-end of SPL in a renewed injection chain for the LHC, which could be progressively constructed over the next decade. After briefly introducing the motivations and layout of the new injector chain, the talk will present the characteristics of the new linacs and give an overview of their main technical features and the R&D activities pursued within the HIPPI Joint Research Activity.
ANL, Argonne
Fermilab, Batavia
Funding: This work was supported by the U.S. Department of Energy, Office of Scince, under contracts number DE-AC02-06CH11357 and No. W-31-109-ENG-38.
The proposed 8 GeV proton driver (PD) linac at FNAL includes a front end up to ~420 MeV and a high energy section operating at 325 MHz and 1300 MHz respectively. A normal conducting RFQ and short H-type resonators are being developed for the initial acceleration of the H-minus or proton beam up to 10 MeV. From 10 MeV to ~420 MeV the voltage gain is provided by SC spoke-loaded cavities. In the high-energy section, the acceleration will be provided by the International Linear Collider (ILC)-style SC elliptical cell cavities. To employ the existing readily available klystrons, an rf power fan out from high-power klystrons to multiple cavities is being developed. The beam dynamics simulation code TRACK available in both serial and parallel versions has been updated to include H-minus stripping due to all known mechanisms to predict the exact location of beam losses. An iterative procedure has been developed to interact with the transient beam loading model taking into account feedback and feedforward systems applied for the rf distribution from one klystron to multiple cavities.
CEA, Gif-sur-Yvette
In the framework of the European CARE-HIPPI program we develop components for superconducting high pulsed power proton linacs at 704 MHz. We have designed, fabricated and tested a beta 0.47 5-cell elliptical cavity with an optimized stiffening to reduce its sensitivity to Lorentz forces. A fast piezo tuner has been developed in order to be able to operate the cavity in pulsed mode in our horizontal test cryostat CryHoLab. We also have carried out the development of a fundamental power coupler. It is designed to transmit a power up to 1 MW at a 10% duty cycle. A high power test area has been setup consisting of a 1.2 MW klystron, a pulsed high voltage power supply and a coupler test stand.
IAP, Frankfurt am Main
Funding: GSI, BMBF contr. No. 06F134I, EU contr. No. 516520-FI6W, RII3-CT-2003-506395, EFDA/99-507ERB500CT990061
Worldwide there is an increasing interest in new high intensity proton and ion driver linacs with beam powers up to several MW. A very challenging part of these accelerators is the low and medium energy section up to 100 MeV. Depending on the duty cycle room temperature or superconducting options are favoured. In both cases the Crossbar-H-mode (CH)-structure, developed at the IAP in Frankfurt is an excellent candidate. Room temperature as well as superconducting prototype cavities have been developed and tested successfully. A superconducting 19 cell low energy (beta=0.1) CH-cavity at 360 MHz reached effective gradients of 7 MV/m corresponding to an accelerating voltage of 5.6 MV. This cavity could be used for high intensity, cw operated linacs like accelerator driven systems (ADS, EUROTRANS) or the international fusion material irradiation facility (IFMIF). Additionally, the new proton injector for FAIR (325 MHz, 70 mA, 70 MeV) will use room temperature CH-cavities. Recent developments of this new type of a multi-cell drift tube cavity, beam dynamics issues and the tests of the prototypes will be presented.
RAS/INR, Moscow
For intense proton beam acceleration the structure aperture diameter should be ~30 mm. With such aperture room temperature coupled cell accelerating structures have the maximal effective shunt impedance Ze at operating frequency ~650 MHz. For this frequency well known Side Coupled Stricture (SCS), Disk and Washer Structure (DAW), Annular Coupled Structure (ACS) have large transversal dimension, leading to essential technological problems. The Cut Disk Structure (CDS) has been proposed to join high Ze and coupling coefficient kc values, but preferably for high energy linacs. In this report parameters of the four windows CDS option are considered at operating frequency ~700 MHz for proton energy range from 80 MeV to 200 MeV. The cells diameter ~30 cm and kc ~0.12 result naturally, but Ze value is of (0.7-0.9) from Ze value for SCS (kc=0.03). Small cells diameter opens possibility of CDS applications for twice lower frequency and structure parameters at operating frequency ~ 350 MHz are estimated too. Cooling conditions for heavy duty cycle operation are considered.
GSI, Darmstadt
During the LINAC conference in Knoxville 2006 the operating frequency of the FAIR proton linac was fixed at 325.224 MHz. Even though the six CH-Structures need slightly different rf levels, the proton linac will be equipped with identical rf power sources. That applies although for the RFQ structure. To supply the FAIR accelerators with a good beam quality by the UNILAC as the high current heavy ion injector for FAIR, as well as an high duty factor accelerator for nuclear physics experiments, different upgrades and modifications have to be made at the rf components. In addition there has to be an upgrade for a planned 50% duty cycle mode, higher beam load within the post-stripper section as well as the provision of an excellent rf operation for the next 30 years. Discussions on possible collaborations with CERN in terms of LLRF and the combining of the procurement for tube amplifiers for bunching cavities are on the way. This paper describes the actual status of the proton linac rf system and the future requirements for the existing UNILAC rf systems.
TRIUMF, Vancouver
A major focus of the linac community is to develop technology in support of the ILC project. The science motivation for the ILC will be presented with reference to the particle physics programs at Fermilab and the LHC.