RadiaBeam, Santa Monica, USA
LLNL, Livermore, California, USA
MIT, Cambridge, Massachusetts, USA
UCLA, Los Angeles, California, USA
Penn State University, University Park, Pennsylvania, USA
BNL, Upton, Long Island, New York, USA
Because of the broad application space for compact, 1-2 GeV accelerators, Inverse Free Electron Lasers (IFELs) are enjoying a rebirth of R&D funding. The efforts are under way in industry (RadiaBeam), academia (UCLA), and national laboratories (LLNL and BNL) to develop an ultra-compact IFEL energy booster for the photoinjector driven linear accelerating systems. The RUBICON collaboration integrates many of the institutions for proof-of-principle IFEL driven Inverse Compton Scattering (ICS) compact light source demonstrations. IFELs perform optimally in this mid-energy range, and given continual advances in laser technology, high average power IFELs with gradients well over 500 MeV/m are now feasible, leading to high quality, compact ICS and Free Electron Laser light sources. Importantly, IFEL operation can have excellent shot-to-shot energy stability, which is crucial when not only driving these light sources, but also for the downstream applications such as photofission, nuclear resonance fluorescence and standoff detection.
ESS Bilbao, Bilbao, Spain
Bilbao, Faculty of Science and Technology, Bilbao, Spain
University of the Basque Country, Faculty of Science and Technology, Bilbao, Spain
ESS-Bilbao, Zamudio, Spain
Imperial College of Science and Technology, Department of Physics, London, United Kingdom
STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom
The Bilbao Accelerator RFQ is aimed to accelerate a 75 mA proton beam from 75 keV to 3 MeV, while keeping the beam both transversely and longitudinally focused, and presenting a minimum emittance growth. We report on the current status of the project, mainly focusing on the Beam Dynamics aspects of the design. Several particle simulations are carried out with RFQSIM, GPT and TRACK codes, in order to study the particle transmission of the RFQ under several circumstances, such as different current levels, vane geometry changes due to thermal stress, and different input beam characteristics obtained by changing the LEBT operation settings.
BNL, Upton, Long Island, New York, USA
ANL, Argonne, USA
Euclid TechLabs, LLC, Solon, Ohio, USA
Illinois Institute of Technology, Chicago, Illinois, USA
The AWA Facility is presently undergoing several upgrades that will enable it to further study wakefield acceleration driven by high charge electron beams. The facility employs an L-band photocathode RF gun to generate high charge short electron bunches, which are used to drive wakefields in dielectric loaded structures as well as in metallic structures (iris loaded, photonic band gap, etc). Several facility upgrades are underway: (a) a new RF gun with a higher quantum efficiency photocathode will replace the RF gun that has been used to generate the drive bunches; (b) the existing RF gun will be used to generate a witness beam to probe the wakefields; (c) three new L-band RF power stations, each providing 25 MW, will be added to the facility; (d) five linac structures will be added to the drive beamline, bringing the beam energy up from 15 MeV to 75 MeV. The drive beam will consist of bunch trains of up to 32 bunches spaced by 0.77 ns with up to 100 nC per bunch. The goal of future experiments is to reach accelerating gradients of several hundred MV/m and to extract RF pulses with GW power level.
UCLA, Los Angeles, USA
Manhattanville College, Purchase, New York, USA
A micron-scale dielectric-based slab-symmetric accelerator is currently being designed and fabricated at UCLA. This Micro-Accelerator Platform (MAP) accelerates electrons in a 800nm wide vacuum gap via a resonant accelerating mode excited by a side-coupled optical-wavelength laser. Detailed results of particle dynamics and field simulations are presented. In particular, we examine various methods of achieving net acceleration and particle stability. Additionally, structural designs that produce accelerating fields synchronous with both relativistic and sub-relativistic electrons are discussed.
SLAC, Menlo Park, California, USA
Muons, Inc, Batavia, USA
JLAB, Newport News, Virginia, USA
The Neutrino Factory baseline design involves a complex chain of accelerators including a single-pass linac, two recirculating linacs and an FFAG. The first linac follows the capture and bunching section and accelerates the muons from about 244 to 900 MeV. It must accept a high emittance beam about 30 cm wide with a 10% energy spread. This linac uses counterwound, shielded superconducting solenoids and 201 MHz superconducting cavities. Simulations have been carried out using several codes including Zgoubi, OptiM, GPT, and G4beamline, both to determine the optics and to estimate the radiation loads on the elements due to beam loss and muon decay.
UCLA, Los Angeles, California, USA
Acceleration of electrons in wakefields set up by a series of drive bunches in a dielectric structure has been proposed as a possible component of next-generation accelerators. Here, we discuss future experimental work with a slab sub-millimeter dielectric loaded accelerator structure that in contrast to conventional dielectric tubes should diminish the effects of transverse wakes and will permit higher total charge to be accelerated. The proposed experiment will allow the generation of unprecedented peak power at THz frequencies. In addition, it can generate ~50-150 MV/m drive fields and thus will allow the testing of acceleration using witness and drive beams. We examine details of the geometry and composition of the structures to be used in the experiment.
LBNL, Berkeley, California, USA
Plasma accelerators may be driven by the ponderomotive force of an intense laser or the space-charge force of a charged particle beam. Plasma wake excitation driven by lasers or particle beams is examined, and the implications of the different physical excitation mechanisms for accelerator design are discussed.
LBNL, Berkeley, California, USA
In order to build a compact, staged laser plasma accelerator the in-coupling of the laser beam to the different stages represents one of the key issues. To limit the spatial foot print and thus to realize a high overall acceleration gradient, a concept has to be found which realizes this in-coupling within a few centimeters. We present experiments on a tape-drive based plasma mirror which could be used to reflect the focused laser beam into the acceleration stage.
References:
* W. Leemans et. al, Phys. Today, 62, 44 (2009)
** G. Doumy et. al, Phys. Rev. E 69, 026402 (2004)
*** B. Dromey et. al,, Rev. Sci. Instrum. 75, 645 (2004)
Stanford University, Stanford, California, USA
SLAC, Menlo Park, California, USA
We present our progress in the fabrication and measurement of a transmission-based dielectric double-grating accelerator structure. The structure lends itself to simpler coupling to the accelerating mode in the waveguide with negligible group velocity dispersion effects, allowing for operation with ultra-short (fs) laser pulses. This document describes work being done at the Stanford Nanofabrication Facility to create a monolithic guided-wave structure with 800 nm period gratings separated by a fixed sub-wavelength gap using standard optical lithographic techniques on a fused silica substrate. An SEM and other characterization tools were used to measure the fabrication deviations of the grating geometry and simulations were carried out in MATLAB and HFSS to study the effects of such deviations on the resulting accelerating gradient.
The Pennsylvania State University, University Park, Pennsylvania, USA
Penn State University, University Park, Pennsylvania, USA
Sensing of shielded fissile materials at long range is critically dependent on the development of compact particle accelerators. Direct laser acceleration (DLA) of electrons has the potential to meet this requirement. In DLA, the axial component of the electric field of a focused radially polarized laser pulse accelerates particles. The acceleration gradient could be estimated as 77 MeV/mm for 800 nm laser with power of 0.5 TW and 8.5 μm guided mode radius. The implementation of long guided propagation of laser pulses and the phase matching between electrons and laser pulses may limit the DLA in reality. A preformed corrugated plasma waveguide could be applied to extend the laser beam propagation distance and for quasi-phase matching between laser and electron pulses for net acceleration. We perform numerical calculations to estimate the phase matching conditions for a radially polarized laser pulse propagating in a corrugated plasma waveguide. Further, the electric field distribution of a radially polarized laser pulse propagating in this waveguide is also analyzed via particle-in-cell simulations, and will be used to guide future experiments.
* P. Serafim, et al., IEEE Trans. Plasma Sci. 28, 1155 (2000).
** A.G. York, et al., Phys. Rev. Lett. 100, 195001 (2008).
Yale University, Beam Physics Laboratory, New Haven, Connecticut, USA
ANL, Argonne, USA
Omega-P, Inc., New Haven, Connecticut, USA
Columbia University, New York, USA
Northern Illinois University, DeKalb, Illinois, USA
NSC/KIPT, Kharkov, Ukraine
Recent tests of a two-channel rectangular dielectric lined accelerator structure are described; comparison with theory and related issues are presented. The structure (with channel width ratio 6:1) is designed to have a maximum transformer ratio of ~12.5:1. It operates mainly in the LSM31 mode (~ 30GHz). The dielectric liner is cordierite (dielectric constant ~4.76). The acceleration gradient is 1.2 MV/m for each 10nC of the drive bunch for the first acceleration peak of the wakefield, and 0.92 MV/m for the second peak. The structure is installed into the AWA beam-line (Argonne National Lab) and is excited by a single 10-50nC, 14MeV drive bunch. Both the drive bunch and a delayed witness bunch are produced at the same photocathode. This is the first experiment to test a two-channel dielectric rectangular wakefield device where the accelerated bunch may be continuously energized by the drive bunch. The immediate experimental objective is to observe the energy gain and spread, and thereby draw conclusions from the experimental results and the theory model predictions. The observed energy change of the test bunch might be well explained*.
* G. V. Sotnikov, et al., Advanced Accelerator Concepts: 13th Workshop, Carl B. Schroeder, Wim Leemans and Eric Esarey, editors, AIP Conf. Proc. 1086), pp. 415–420 (AIP, New York, 2009).
MPI-P, München, Germany
LANL, Los Alamos, New Mexico, USA
UCLA, Los Angeles, California, USA
NSC/KIPT, Kharkov, Ukraine
Yale University, Physics Department, New Haven, CT, USA
Omega-P, Inc., New Haven, Connecticut, USA
A key parameter of wakefield acceleration is the transformer ratio T. For a dielectric wakefield accelerator, it has been suggested to use a ramped drive bunch train (RBT), or a multizone dielectric structure to enhance T. Here we show the possibility of greatly improving the RBT technique by the use of a numerical algorithm. We study a two-channel 28 GHz structure with two nested Alumina cylindrical shells (CDWA) which is to be excited by a train of four annular bunches having energy 14 MeV and axial RMS size 1mm; the total charge of bunches is 200 nC. For bunch charge and spacing chosen for optimum acceleration gradient, or for optimizing T using the standard method, we obtain T~3.6. We found that if the charge ratios are 1.0:2.4:3.5:5.0 and the spaces between the bunches are 2.5, 2.5, and 4.5 wakefield periods, then T~17. The RBT also can be used successfully in a high gradient THz CDWA structure.
* C.Jing et.al., Phys. Rev. Lett. 98 144801, (2007)
** C. Wang, et.al. Proc. PAC 2005. IEEE, 2005, p.1333.
*** G. Sotnikov et.al. PRST-AB, 061302 (2009).
Euclid TechLabs, LLC, Solon, Ohio, USA
ANL, Argonne, USA
We report on a collinear wakefield experiment using the first tunable dielectric loaded accelerating structure. Dielectric-based accelerators are generally lacking in approaches to tune the frequency after fabrication. However, by introducing an extra layer of nonlinear ferroelectric which has a dielectric constant sensitive to temperature and DC voltage, the frequency of a DLA structure can be tuned on the fly by controlling the temperature or DC bias. The experiment demonstrated that by varying the temperature of the structure over a 50°C temperature range, the energy of a witness bunch at a fixed delay with respect to the drive beam could be changed by an amount corresponding to more than half of the nominal structure wavelength.
LLNL, Livermore, California, USA
UCLA, Los Angeles, California, USA
We describe the Inverse Free Electron Laser (IFEL) accelerator currently under construction at LLNL in collaboration with UCLA. This project combines a strongly tapered undulator with a 10 Hz repetition rate, Ti:Sapphire laser to produce > 200 MeV/m average accelerating gradient over the 50 cm long undulator. The project goal is to demonstrate IFEL accelerator technology that preserves the input beam quality and is well suited for future light source applications. We discuss the accelerator design focusing on issues associated with the use of 800 nm, 100 fs laser pulses. Three-dimensional simulations of the IFEL interaction are presented which guide the choice of laser and electron beam parameters. Finally, experimental plans and potential future developments are discussed.
Yale University, Beam Physics Laboratory, New Haven, Connecticut, USA
Yale University, Physics Department, New Haven, CT, USA
Omega-P, Inc., New Haven, Connecticut, USA
An axially-asymmetric cavity to support several modes at harmonically-related frequencies is predicted to sustain higher RF breakdown thresholds than a conventional pillbox cavity, when driven by two or more external RF phase-locked harmonic sources. Experimental efforts are underway at Yale Beam Physics Lab to study RF breakdown in a bimodal asymmetric cavity. Such a cavity could be a basic building-block for a future high-gradient warm accelerator structure.
* S.Yu. Kazakov, S.V. Kuzikov, Y. Jiang, and J.L. Hirshfield, PRSTAB, 13, 071303 (2010).
** S.V. Kuzikov, S.Yu. Kazakov, Y. Jiang, and J.L. Hirshfield, PRL 104, 214801 (2010).
CELIA, Talence, France
Fermilab, Batavia, USA
A longitudinal beam properties, data acquisition system has been commissioned to operate in the Fermilab booster ring. This system captures real time information including beam synchronous phase, bunch length, and coupled bunch instability amplitudes as the beam is accelerated from 400MeV to 8GeV in 33ms. The system uses an off-the-shelf Tektronix oscilloscope running Labview software and a synchronous pulse generator. This paper describes the hardware configuration and the software configuration used to optimize the data processing rate.
LANL, Los Alamos, New Mexico, USA
USC, Los Angeles, California, USA
BNL, Upton, Long Island, New York, USA
We present initial experimental results showing the excitation of plasma wakefields by a train of two drive bunches. These wakefields are experienced by a trailing witness bunch that gains energy while retaining a finite energy spread. These well controlled plasma wakefield accelerator (PWFA) experiments are important to test the theory of the PWFA and serve as a testbed for techniques that will be used in high energy experiments.
SLAC, Menlo Park, California, USA
UCLA, Los Angeles, California, USA
USC, Los Angeles, California, USA
FACET, the Facility for Advanced Accelerator and Experimental Tests, is a new facility being constructed in sector 20 of the SLAC linac primarily to study beam driven plasma wakefield acceleration beginning in summer 2011. The nominal FACET parameters are 23GeV, 3nC electron bunches compressed to ~20μm long and focused to ~10μm wide. The intense fields of the FACET bunches will be used to field ionize neutral lithium or cesium vapor produced in a heat pipe oven. Previous experiments at SLAC demonstrated 50GeV/m gradients in an 85cm field ionized lithium plasma where the interaction distance was limited by head erosion. Simulations indicate the lower ionization potential of cesium will decrease the rate of head erosion and increase single stage performance. The initial experimental program will compare the performance of lithium and cesium plasma sources with single and double bunches. Later experiments will investigate improved performance with a pre-ionized cesium plasma. The status of the experiments and expected performance are reviewed.
MPI-P, München, Germany
UCLA, Los Angeles, California, USA
CERN, Geneva, Switzerland
Instituto Superior Tecnico, Lisbon, Portugal
LANL, Los Alamos, New Mexico, USA
BINP SB RAS, Novosibirsk, Russia
USC, Los Angeles, California, USA
HHUD, Dusseldorf, Germany
IPFN, Lisbon, Portugal
Fermilab, Batavia, USA
Muons, Inc, Batavia, USA
LANL, Los Alamos, New Mexico, USA
Fermilab, Batavia, USA
IIT, Chicago, Illinois, USA
An 805 MHz RF pillbox cavity has been designed and constructed to investigate potential muon beam acceleration and cooling techniques. The cavity can operate in vacuum or under pressure to 100 atmospheres, at room temperature or in an LN2 bath at 77 K. The cavity is designed for easy assembly and disassembly with bolted construction using aluminum seals. The surfaces of the end walls of the cavity can be replaced with different materials such as copper, aluminum, beryllium, or molybdenum, and with different geometries such as shaped windows or grid structures. Different surface treatments such as electro polished, high-pressure water cleaned, and atomic layer deposition are being considered for testing. The cavity has been designed to fit inside the 5-Tesla solenoid in the MuCool Test Area at Fermilab. Performance of the cavity, including initial conditioning and operation in the external magnetic field will be reported.
SLAC, Menlo Park, California, USA
Photonic crystal fibers (PCFs) represent a class of optical fibers which have a wide spectrum of applications in the telecom and sensing industries. Currently, the Advanced Accelerator Research Department at SLAC is developing photonic bandgap particle accelerators, which are photonic crystal structures with a central defect used to accelerate electrons and achieve high longitudinal electric fields. Extremely compact and less costly than the traditional accelerators, these structures can support higher accelerating gradients and will open a new era in high energy physics as well as other fields of science. Based on direct laser acceleration in dielectric materials, the so called photonic band gap accelerators will benefit from mature laser and semiconductor industries.
Sheffield University, Sheffield, United Kingdom
Imperial College of Science and Technology, Department of Physics, London, United Kingdom
STFC/RAL, Chilton, Didcot, Oxon, United Kingdom
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
LLNL, Livermore, California, USA
LBNL, Berkeley, California, USA
PPPL, Princeton, New Jersey, USA
UMD, College Park, Maryland, USA
Intense heavy-ion beams have long been considered a promising driver option for inertial-fusion energy production. This paper briefly compares inertial confinement fusion (ICF) to the more-familiar magnetic- confinement approach and presents some advantages of using beams of heavy ions to drive ICF instead of lasers. Key design choices in heavy-ion fusion (HIF) facilities are discussed, particularly the type of accelerator. We then review experiments carried out at Lawrence Berkeley National Laboratory (LBNL) over the past thirty years to understand various aspects of HIF driver physics. A brief review follows of present HIF research in the US and abroad, focusing on a new facility, NDCX-II, being built at LBNL to study the physics of warm dense matter heated by ions, as well as aspects of HIF target physics. Future research directions are briefly summarized.
SLAC, Menlo Park, California, USA
SLAC, Menlo Park, California, USA
FACET, the Facility for Advanced Accelerator and Experimental Tests, is a new facility being constructed in sector 20 of the SLAC linac primarily to study beam driven plasma wakefield acceleration. The FACET beamline consists of a chicane and final focus system to compress the 23 GeV, 3 nC electron bunches to ~20μm long and ~10μm wide. Simulations of the FACET beamline indicate the short-duration and large, 1.5% rms energy spread beams may suffer a factor of four emittance growth from a combination of chromaticity, incoherent synchrotron radiation (ISR), and coherent synchrotron radiation (CSR). Emittance growth is directly correlated to head erosion in plasma wakefield acceleration and is a limiting factor in single stage performance. Studies of the geometric, CSR, and ISR components are presented. Numerical calculation of the rms emittance can be overwhelmed by long tails in the simulated phase space distributions; more useful definitions of emittance are given. A complete simulation of the beamline is presented as well, which agrees with design specifications.
The University of Texas at Austin, Austin, Texas, USA
Fermilab, Batavia, USA
Tech-X, Boulder, Colorado, USA
BNL, Upton, Long Island, New York, USA
We have benchmarked UAL-SPINK against Zgoubi and a list of well understood spin physics results. Along the way we addressed issues relating to longitudinal dynamics and orbit bump and distortion handling as well as appropriate slicing necessary for the TEAPOT-SPINK spin orbit integrator. We have also ported this TEAPOT-SPINK algorithm to the GPU’s. We present the challenges associated with this work.
Fermilab, Batavia, USA
BNL, Upton, Long Island, New York, USA
In the context of the evaluation of possibly using the Fermilab Electron Cooler for the proposed low-energy RHIC run at BNL, operating the cooler at 1.6 MeV electron beam energy was tested in a short beam line configuration. The main conclusion of this feasibility study is that the cooler's beam generation system is suitable for BNL needs. The beam recirculation was stable for all tested parameters. In particular, a beam current of 0.38 A was achieved with the cathode magnetic field up to the maximum value presently available of 250 G. The energy ripple was measured to be 40 eV. A striking difference with running the 4.3 MeV beam (nominal for operation at FNAL) is that no unprovoked beam recirculation interruptions were observed.
BINP SB RAS, Novosibirsk, Russia
Fermilab, Batavia, USA
A realistic approach to calculate the transport matrix in RF cavities is developed. It is based on joint solution of equations of longitudinal and transverse motion of a charged particle in an electromagnetic field of the linac. This field is a given by distribution (measured or calculated) of the component of the longitudinal electric field on the axis of the linac. New approach is compared with other matrix methods to solve the same problem. The comparison with code ASTRA has been carried out. Complete agreement for tracking results for a TESLA-type cavity is achieved. A corresponding algorithm has been implemented into the MARS15 code.
Tech-X, Boulder, Colorado, USA
We present recent results of prototyping general-purpose particle tracking on GPUs, discussing our CUDA implementation of transfer maps for single-particle dynamics and collective effects. Our goal being incorporation of the GPU-accelerated tracking into ANL's accelerator code ELEGANT, we used the code's quadrupole and drift-with-LSC elements as test cases. We discuss the use of data-parallel and hardware-assisted approaches (segmented scan and atomic updates) for resolving memory contention issues at the charge deposition stage of algorithms for modeling collective effects.
BNL, Upton, Long Island, New York, USA
MPI-K, Heidelberg, Germany
JINR/DLNP, Dubna, Moscow region, Russia
Aarhus University, Aarhus, Denmark
JINR, Dubna, Moscow Region, Russia
The University of Liverpool, Liverpool, United Kingdom
Cockcroft Institute, Warrington, Cheshire, United Kingdom
At present, the only place in the world where experiments utilising low-energy antiprotons can be performed is the AD at CERN. The MUSASHI trap, as part of the ASACUSA collaboration, enables access to antiproton energies in the order of a few hundreds of eV. Whilst MUSASHI produces cutting-edge research, the available beam quality and luminosity is not sufficient for collision experiments on the level of differential cross sections. A small electrostatic ring, and associated electrostatic acceleration section, is being designed and developed by the QUASAR Group. It will serve as a prototype for the future ultra-low energy storage ring (USR), to be integrated at the facility for low-energy antiproton and ion research (FLAIR). This small AD recycler ring will be unique due to its combination of size, electrostatic nature and energy of the circulating particles. In this contribution, the design of the ring is described and details about the injection section are given.
NSCL, East Lansing, Michigan, USA
Kress GmbH, Biebergemuend, Germany
GSI, Darmstadt, Germany
FRIB, East Lansing, Michigan, USA
IAP, Frankfurt am Main, Germany
The Facility for Rare Isotope Beams (FRIB) is currently in the preliminary design phase at Michigan State University (MSU). FRIB consists of a driver LINAC for the acceleration of heavy ion beams, followed by a fragmentation target station and a ReAccelerator facility (ReA3). ReA3 comprises gas stopper systems, an Electron Beam Ion Trap (EBIT) charge state booster, a room temperature radio frequency quadrupole (RFQ), a LINAC using superconducting quarter wave resonators and an achromatic beam transport and distribution line to the new experimental area. Beams from ReA3 will range from 3 MeV/u for heavy ions to about 6 MeV/u for light ions. The ReA3 RFQ, which is of the 4 rod type, is designed to accelerate ions with an Q/A of 0.2 to 0.5 from 12 keV/u to 600 keV/u. The RFQ operates at a frequency of 80.5 MHz and power levels up to 120 kW at 10% duty factor. In this paper we will report on commissioning results from the ReA3 RFQ using a H2+ and He+ beam from an auxiliary ion source.
UMAN, Manchester, United Kingdom
STFC/DL, Daresbury, Warrington, Cheshire, United Kingdom
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
EMMA is the first non-scaling FFAG to be constructed, whose use of linear magnets means that the accelerating electron bunch rapidly crosses many resonances. We have modeled the capture and acceleration of bunches in the serpentine channel created by the radio-frequency cavities, and compare it to a proposed experiment in which induction cells allow slow acceleration. Two induction cores each providing ~20kV over 1.65 μs enable a number of resonance crossing experiments.
BNL, Upton, Long Island, New York, USA
UCLA, Los Angeles, California, USA
SLAC, Menlo Park, California, USA
Stanford University, Stanford, California, USA
Optical scale dielectric structures offer a promising medium for high-gradient, compact, low-cost acceleration of charged particles. An experimental program is underway at the SLAC E163 facility to demonstrate acceleration in photonic bandgap structures driven by short laser pulses. We present initial experimental results, discuss structure and experimental design, and present first estimates of achievable gradient.
Euclid TechLabs, LLC, Solon, Ohio, USA
ANL, Argonne, USA
Diamond has been proposed as a dielectric material for dielectric loaded accelerating (DLA) structures. It has a very low microwave loss tangent, the highest available thermoconductive coefficient and high RF breakdown field. In this paper we report the results from a wakefield breakdown test of diamond-loaded rectangular accelerating structure and development of a cylindrical diamond DLA. We expect to achieve field levels on the order of 100 MV/m in the structure using the 100nC beam at the Argonne Wakefield Accelerator Facility. Single crystal diamond plates produced by chemical vapor deposition (CVD) are used in the structure. The structure is designed to yield up to 0.5 GV/m fields on the diamond surface to test it for breakdown. A surface analysis of the diamond is performed before and after the beam test.
Fermilab, Batavia, USA
MSU, East Lansing, Michigan, USA
TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada
IIT, Chicago, Illinois, USA
The drive for higher beam power, duty cycle, and reliable beams at reasonable cost has focused world interest on fixed field accelerators, notably FFAGs. High-intensity GeV proton drivers encounter duty cycle and space-charge limits in the synchrotron and machine size concerns in cyclotrons. A 10-20 MW proton driver is challenging, if even technically feasible, with conventional circular accelerators. Recently, the concept of isochronous orbits has been developed for nonscaling FFAGs using powerful new methodologies in FFAG accelerator design. Isochronous orbits enable the simplicity of fixed RF and, by tailoring the field profile, the FFAG can remain isochronous beyond the energy reach of cyclotrons. With isochronous orbits, the machine proposed here has the high average current advantage and duty cycle of the cyclotron in combination with the strong focusing, smaller losses that are more typical of the synchrotron. With the cyclotron as the current industrial and medical standard, a competing CW FFAG would impact facilities using medical accelerators, proton drivers for neutron production, and accelerator-driven nuclear reactors. This work reports on these new advances.
JINR, Dubna, Moscow Region, Russia
JINR/DLNP, Dubna, Moscow region, Russia
BNL, Upton, Long Island, New York, USA
As the worlds’s first high energy polarized proton col- lider, RHIC has made significant progresses in measuring the proton spin structure in the past decade. In order to have better understanding of the contribution of u quark and d quark to the proton spin structure, collisions of high energy polarized neutron beams are required. In this paper, we discuss the perspectives of accelerating polarized light ions, like deuteron, Helium-3 and tritium. We also repre- sent simulation studies of accelerating polarized Helium-3 in RHIC.
Brookhaven National Lab., Upton, NY 11973
NSCL, East Lansing, Michigan, USA
FRIB, East Lansing, Michigan, USA
The Facility for Rare Isotope Beams (FRIB) will be a world-leading, DOE national users facility for the study of nuclear structure, reactions and astrophysics on the campus of Michigan State University. A superconducting, heavy-ion, driver linac will be used to provide stable beams of >200 MeV/u at beam powers up to 400 kW (~650 electrical micro-amps for uranium) that will be used to produce rare isotopes by in flight fragment separation. The selected rare isotopes will be used at velocity (~0.5 c), stopped, or reaccelerated. FRIB is a challenging technical project. An overview of the project, project challenges, and mitigating strategies will be presented.