ORNL, Oak Ridge, Tennessee
LBNL, Berkeley, California
Multi-particle tracking simulations for the SNS linac beam dynamics studies are performed with the IMPACT code. Beam measurement results are compared with the simulations, including beam halos and beam loss in the superconducting linac, measurement of beam transverse twiss parameters and beam longitudinal emittance in the SNS linac. And in most cases, the simulations show good agreement with the measured results.
GSI, Darmstadt
ORNL, Oak Ridge, Tennessee
CEA, Gif-sur-Yvette
Systematic measurements on transverse rms-emittance growth along the Alvarez DTL of the GSI UNILAC were performed. A high intensity argon beam was used to measure rms-growth for different transverse phase advances along the DTL. The transverse tune depression varied from 21% to 43%. For benchmarking of the experimental results four different beam dynamics codes were used: DYNAMION, PARMILA, PARTRAN, and LORASR. This paper is on the results of the experiments, the reconstruction of the initial conditions for the simulations, and on the agreement between simulations and experiments. Additionally, successful suppression of rms-growth by systematic matching is reported.
KEK, Ibaraki
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken
The beam commissioning of J-PARC linac has been started since November 2006. Numerical studies have been conducted since then to analyze the experimental results obtained in the beam commissioning and deepen our understanding on the underlying physics. Particular efforts are exerted on the analyses of the transverse emittance measurement at MEBT, the phase scan measurement for DTL, and the rms width response to a quadrupole magnet variation. All the measurements are essential to realize a fine tuning of the linac, and it is of practical importance to have a physical insight into the obtained results. In these studies, various simulation tools are employed in accordance with the required capacity. In this paper, the on-going numerical studies for J-PARC linac are reviewed, and we discuss on the directions in which we should pay further efforts.
IAP, Frankfurt am Main
GSI, Darmstadt
The 'Combined Zero-Degree Structure' ('Kombinierte Null Grad Struktur - KONUS') beam dynamics concept is described in detail. A KONUS period consists of a quadrupole triplet or a solenoid lens, a rebuncher section at negative synchronous phase and a multi cell zero degree synchronous particle main acceleration section. This concept is especially effective when applied for accelerator designs using H-mode resonators with ‘slim’ drift tubes which carry no focusing elements. The definition and typical ranges of KONUS lattice parameters are discussed on a general level, as well as on the basis of examples for realized or planned high current accelerators, like the GSI High Current Injector (HSI), the 70 mA, 3-70 MeV Proton Injector for the FAIR Facility and our proposal of a 125 mA D+, 5-40 MeV superconducting CH-DTL section for the International Fusion Materials Irradiation Facility (IFMIF).
GSI, Darmstadt
IAP, Frankfurt am Main
The FAIR facility at GSI requires a dedicated proton injector for the production of secondary high intensity antiproton beams. This 325 MHz, 70 MeV machine will be the fist linac based on CH cavities operated with Konus beam dynamics. Two different options for the beam dynamics layout are under investigation including loss and error studies. Finally different RFQ output distribution are used to evaluate the injection current into the main linac.
CERN, Geneva
CEA, Gif-sur-Yvette
Linac4 is a normal conducting H- linac to be built at CERN as a new injector to the PS Booster and later on as a front end of a possible MultiMegaWatt Linac Facility. The layout consists of a H- RF source, a magnetic LEBT, a RFQ (accelerating the beam from 45 keV to 3 MeV), a chopper line, a conventional Drift Tube Linac (from 3 MeV to 50 MeV), a Coupled Cavity Drift Tube Linac (from 50 MeV to 100 MeV) and a pi-mode structure (PIMS, from 100 to 160 MeV), all operating at a frequency of 352 MHz. End-to-end beam dynamics simulations have been carried out to optimise the design and performance of the accelerator. An extensive statistical campaign of transverse error studies was then launched for accessing the required alignment tolerances and steering correction system.
LANL, Los Alamos, New Mexico
The heart of the Los Alamos Neutron Science Center (LANSCE) is a pulsed linear accelerator that is used to simultaneously provide H+ and H- beams to several user facilities. This accelerator contains two Cockcroft-Walton style injectors, a 100-MeV drift tube linac and an 800-MeV coupled cavity linac. This presentation will touch on various aspects of the high power operation including performance and limitations, tune-up strategy, beam losses and machine protection.
University of the Basque Country, Faculty of Science and Technology, Bilbao
Bilbao, Faculty of Science and Technology, Bilbao
Fundación TEKNIKER, Eibar (Gipuzkoa)
Elytt Energy, Madrid
A revised layout for the proton linear accelerator as proposed by the European Spallation Source-Bilbao (Spain) bid to host the installation is here described. The new machine concept aims to incorporate advances which have been registered within the ï¬eld of high power accelerators during the last decade. Particularly relevant are the ongoing works within Magnetic Fusion activities (IFMIF/EVEDA), waste transmutation (EUROTRANS) or radioactive ion beam (EURISOL) and heavy-ion physics (FAIR, SPIRAL2) which have lead to signiï¬cantly shorter accelerators incorporating state-of-the-art technology which mainly replaces decades-old copper drift-tubes, coupled-cavity LINACs or some other accelerating structures employed for energies beyond 50 MeV or so by superconducting cavities (SC) of a wholly new kind. The design of such a new accelerator layout will be critically dependent upon the development and/or adaptation of low β superconducting cavities already developed for some of the referred projects into those adequate for pulsed operation and high duty cycle.
The authors wish to acknowledge extremely fruitful discussions held with scientists from CEA/SACLAY, IPN/ORSAY as well as from the ISIS Spallation Neutron Source.
KAERI, Daejon
The main purposes of the proton engineering frontier project (PEFP) are developing 100-MeV proton linac and supplying 20-MeV and 100-MeV proton beams to user group. The 20-MeV part of the linac with 24% beam duty has been successfully installed and tested at the KAERI site. Now we are supplying 20-MeV proton beams to users in a restricted beam condition. The fabrication of the remaining part of the DTL with the beam duty of 8% is in progress. The PEFP user facility includes 5 beam lines for 20-MeV and 100-MeV beams, respectively. Form the user surveys the purposes and beam specs are determined for the beam lines. The characteristics of the PEFP beam supplying systems are using the AC magnets to periodically distribute proton beams into several beam lines. At the same time, PEFP concentrates on developing the potential user group of the high intensity proton beams. Several beam utilization programs are under way for this purpose. The civil construction is scheduled to start at the end of this year. The present status and progress of the project are summarized in detail.
LANL, Los Alamos, New Mexico
We are developing a compact deuteron-beam accelerator up to the energy of a few MeV based on room-temperature inter-digital H-mode (IH) accelerating structures with the transverse beam focusing using permanent-magnet quadrupoles (PMQ). Combining electromagnetic 3-D modeling with beam dynamics simulations and thermal-stress analysis, we show that IH-PMQ structures provide very efficient and practical accelerators for light-ion beams of considerable currents at the beam velocities around a few percent of the speed of light. IH-structures with PMQ focusing following a short RFQ can also be beneficial in the front end of ion linacs.