ORNL, Oak Ridge, Tennessee
This talk will present the stutus of SNS operation at 1MW and plan beyond it.
KEK, Ibaraki
In order to improve the positron beam intensity needed for super KEKB project, it was decided to replace the present S-band structures in the positron capture section by a new L-band (1298MHz) accelerator system. A 2m long TW structure of 12MV/m gradient is now under idesign process while a 40MW klystron will be delivered in summer. After the klystron testing, a single L-band accelerator unit will be constructed for the structure study. The study is scheduled in next spring to operate the structure under solenoidal magnetic focussing field.
CERN, Geneva
An RF measurement system has been set up at CERN for use in the X-band accelerating structure development program of the CLIC study. Using the system, S-parameters are measured and the field distribution is obtained automatically by using a bead-pull technique. The corrections for tuning the structure are calculated from the result. Integrated software guides cell-by-cell tuning to obtain the correct phase advance and minimum reflection at the operation frequency. The detailed configuration of the system, as well as the semi-automatic tuning procedure, is presented along with a few examples of measurement and tuning of CLIC accelerating structure prototypes.
The University of Tokyo, Nuclear Professional School, Ibaraki-ken
JAEA, Ibaraki-ken
UTNL, Ibaraki
950 keV X-band Linac has the merits of compact system, and it does not need the radiation safety manager on-site in the public space. Therefore the system we have developed is suitable for the more safe circumstance in airport. Dual energy X-ray concept is introduced for material recognition with Linac these days, because it produce high energy X-ray which is available in case the target is thick and high atomic number material. We suggest two fold scintillator detector concept to induce dual energy X-ray effect. The design of two fold scintillator is decided by MCNP simulation with two scintillator code, CsI and CdWO4. The material recognition is confirmed using aluminium, iron and lead metal in conditions such as various thicknesses and containers.
Osaka Prefecture University, Sakai
A pulsed electron radiography system has been developed, which consisted of an electron linear accelerator, a scintillation screen and a high sensitivity image sensor. The system was capable for high speed strobo-imaging by the use of the pulse feature of the electron beam with the pulse width about a few micro-second. On the other hand, the characteristics of electron images were different from X-ray images and neutron images. Absorption behavior of energetic electrons in materials is Bragg-like rather than exponential. Therefore, a high contrast transparent image was obtained by modulating of energy of the electron beam. By the use of this system and utilizing these features, we observed successfully an ozone explosion phenomenon of liquid nitrogen induced by electron irradiation, which has been considered to be a serious problem in material irradiation experiments.
GSI, Darmstadt
A low current high duty factor U10+-beam from the Penning Ion Source as well as a high current low duty factor U4+-beam from a MeVVa source were used for machine investigations in the GSI-UNILAC and synchrotron (SIS18). Carbon stripper foils (20, 40 and 50 ug/cm2) were mounted in the gas stripper section at 1.4 MeV/u to provide for highly charged uranium ions (40+) to be delivered to the SIS18 for life time beam measurements. High current tests were performed to check the durability of the carbon foils. No measurable variation of the stripped low and high current beam in the poststripper DTL could be detected during the life time of the foils. An U40+-beam current of up to 1.0·10+11 particles per 100mues could be reached in the transfer line to the SIS18. This paper will report on the investigations of stripper foils with different thickness. Additionally long time observation of all relevant beam parameters (transverse emittance, energy spread and energy loss, bunch shape, beam transmission up to the SIS-injection) are presented.
NSCL, East Lansing, Michigan
FRIB, East Lansing, Michigan
The primary purpose of the Facility for Rare Isotope Beams (FRIB) is to produce and to do fundamental research with rare isotopes. The rare isotope production will be accomplished using a heavy ion cw linac to provide a stable isotope beam (protons through uranium) at high power (up to 400 kW) and high energy (>200 MeV/u) on a particle fragmentation production target. The rare isotopes will be produced in quantities sufficient to support world-leading research by using particle fragmentation of stable beams. This will include research pertaining to the properties of nuclei (nuclear structure), the nuclear processes in the universe and tests of fundamental symmetries. Societal applications and benefits may include bio-medicine, energy, material sciences and national security. The overall facility status and plans will be discussed with a focus on the accelerator system.
NSCL, East Lansing, Michigan
FRIB, East Lansing, Michigan
The Facility for Rare Isotope Beams (FRIB) will accelerate stable beams of heavy ions to > 200 MeV/u with beam powers of up to 400 kW onto an in-flight fragmentation target to produce rare isotopes. The accelerator system will include a room-temperature front end, a double-folded superconducting driver linac, and a beam delivery system. The front end will include superconducting ECR ion sources, a beam bunching system and a radio frequency quadrupole. The driver linac will include three acceleration segments using superconducting quarter-wave and half-wave cavities with frequencies of 80.5 and 322 MHz, and two 180 degree folding systems to minimize the cost of conventional construction. Charge-stripping and multi-charge-state beam acceleration will be used for the heavier ions to increase acceleration efficiency. The beam delivery system will transport accelerated stable beams to the in-flight fragmentation target. End-to-end beam simulations with errors have been performed to evaluate the performance of the driver linac. We will discuss recent progress in the accelerator design and the beam dynamics studies for the baseline accelerator system.
LANL, Los Alamos, New Mexico
EPO, Rijswijk
IPF has recently investigated isotope production with proton beams at energies other than the 100-MeV currently available to the IPF beam line. To maximize the yield of a particular isotope, it is necessary to measure the production rate and cross section versus proton beam energy. Studies were conducted at 800 MeV and 197 MeV to determine the cross section of terbium-159. Also, the ability to irradiate targets at different proton beam energies opens up the possibility of producing other radioisotopes. A proof-of-principle test was conducted to develop a 40-MeV tune in the 100-MeV beam line. Another parameter explored was the beam current, which was raised from the normal limit of 250 uA up to 356 uA via both power and repetition rate increase. This proof-of-principle test demonstrated the capability of the IPF beam line for high current operation with potential for higher isotope yields. For the full production mode, system upgrades will need to be in place to operate at high current and high duty factor. These activities are expected to provide the data needed for the development of a new and unique isotope production capability complementing the existing 100-MeV IPF facility.
CERN, Geneva
SLAC, Menlo Park, California
KEK, Ibaraki
Prototype accelerating structures for the Compact Linear Collider (CLIC) are being developed and high-power tested in a collaboration between SLAC, KEK and CERN. Several undamped, low group-velocity and strongly tapered prototypes (of the so-called T18 design) have been operated above 100 MV/m average gradient at a very low breakdown rates. Recently two new structures with the same iris apertures but now including higher order mode damping waveguides in each cell (TD18 design) have been tested at SLAC and KEK. The damped versions could be processed to similar gradients but an increased breakdown rate was observed. The damping waveguides lead to a magnetic field enhancement in the outer diameter of the cells which results in increased pulsed surface heating. The maximum pulsed temperature rise is 80 deg at the design gradient of 100 MV/m compared to only 20 deg for the undamped version. The high-power tests of the two TD18 structures are analyzed with special emphasis on the influence on breakdown rate of the enhanced magnetic field and consequent increased pulsed surface temperature rise.
CERN, Geneva
EPFL, Lausanne
HIP, University of Helsinki
Optimizing the design and the manufacturing of the CLIC RF accelerating structures for achieving the target value of breakdown rate at the nominal accelerating gradient of 100 MV/m requires a detailed understanding of all the steps involved in the mechanism of breakdown. These include surface modification under RF fields, electron emission and neutral evaporation in the vacuum, arc ignition and consequent surface modification due to plasma bombardment. Together with RF tests, experiments are conducted in a simple DC test set-up instrumented with electrical diagnostics and optical spectroscopy. The results are also used for validating simulations which are performed using a wide range of numerical tools (MD coupled to electrostatic codes, PIC plasma simulations) able to include all the above phenomena. Some recent results are presented in this paper.
IN2P3 IPNL, Villeurbanne
UCBL, Villeurbanne
IPN, Orsay
The driver accelerator of the Spiral2 facility will deliver deuteron (40MeV) and proton (33MeV) beams with current up to 5mA and heavy ion (14.5MeV/n) beams up to 1mA. At the very end of the LINAC, the main Beam Stop will have to withstand a peak power of 200kW for deuterons, with an associated power density from 120W/mm2 to more than 700W/mm2. These challenging specifications impose the design of a new high efficiency Beam Stop that has been nicknamed SAFARI (French acronym of Optimized Beam Stop Device for High Intensity Beams). From the beam characteristics and activation constraints, we proposed and developed a complete design. We will present this original design and the different studies and optimizations which have been done: The Beam Stop shape marries to the beam characteristics in order to smooth for the best power density and improve thermo-mechanical behaviour under nominal and critical beams. Cooling system is directly machined from Beam Stop blocks. Optimization by various fluid studies and calculations led us to a new high efficiency counter-current water cooling system. We then compare calculated behaviour with first results obtained on our recent functional mock-up
IAP, Frankfurt am Main
The Frankfurt Neutron source FRANZ is under construction*. The ARMADILLO bunch compressor** as a part of it is composed of a 5MHz electric kicker, a magnetic dipole chicane and rf-rebunching cavities. The design phase of the bunch compressor has reached the final stage. A 175MHz 2MeV proton linac forms 100ns long beam pulses consisting of nineμbunches with 150mA. Deflected by the 5MHz kicker theμbunches are guided on different paths to arrive within 1ns at a n-production target. Due to high space charge forces rebuncher cavities are included***. The peak current at the target is expected to be in the range of 10A in a 1ns proton pulse, which is equivalent to a longitudinal pulse compression ratio of 45. A new code specific for complex magnetic multi aperture system and for high current applications has been developed. Hardware designs according to the beam dynamics results are in progress. Improved 3D magnetic and electric fields will be applied in the future beam dynamics studies including high space charge forces. The preliminary designs and the beam dynamics studies will be presented in this contribution.
* O. Meusel, et al.: LINAC06, Knoxville, Tennessee USA, 2006, pp. 159-161.
** L. P. Chau, et al.: EPAC08, Genoa, Italy, 2008, pp. 3578-3580.
*** D. Noll, another contribution at this conference.
KEK, Ibaraki
A new type of rotating anticathode X-ray generator has been developed, in which the electron beam up to 120keV irradiates the inner surface of a U-shaped Cu anticathode. A high-flux electron beam is obtained by optimizing the geometry of the combined function bending magnet. In order to minimize the sizes of the X-ray source, the electron beam is focused in a short distance by the combined function bending magnet, of which geometrical shape was determined by simulation with the codes of Opera-3D, General Particle Tracer (GPT) and CST STUDIO. The result of simulation clearly shows that the role of combined function in the bending magnet and the steering magnet is important to focus the beam in small sizes. FWHM sizes of the beam were predicted by simulation to be 0.45mm (horizontal) and 0.05mm (vertical) for a beam of 120keV and 75mA of which effective brilliance is about 500kW/mm2 with the supposition of a two-dimensional Gaussian distribution. The beam focus sizes on the target will be verified in the experiments by using the high-voltage power supply for the X-ray generator improved from 60kV to 120kV and 75mA.
RIKEN Nishina Center, Wako
Medium-energy high-intensity heavy-ion beams have been used for more than twenty years as powerful tools to investigate physics of unstable nuclei far from stability, in which one of the major problems is to understand the element genesis in universe. Many facilities including CERN, GANIL, GSI, MSU and RIKEN have developed their facilities to obtain much higher-intensity unstable-nuclei beams. Within these facilities, RIKEN first finished construction and commissioning of a major upgrade plan of the existing facility, RI Beam Factory, three years ago, in which the world-first superconducting ring cyclotron is pushing the limit of energy for heavy-ion cyclotrons. On the other hand, the FAIR and the FRIB project chose different strategies to obtain high-intensity heavy-ion beams, the former uses synchrotron and the latter uses superconducting linacs. The present competition with three different approaches is interesting because it will make clear that which kind of accelerator complex is most effective for medium-energy heavy-ion facilities. In this talk, we will present the achievements and future of RIBF under the comparison with other powerful competitors.
KEK, Ibaraki
Development of the superconducting injector Linac for compact ERL has been continuing at KEK. The cryomodule including three two-cell SC cavities was designed. Two prot-type two-cell cavities were fabricated, and the vertival test were carried out after the standard surface preparation at STF. The high power tests of the input couplers were also carried out at the test stand with 300 kW cw klystron. The status of the cERL injector cryomodue will be reported.
IPN, Orsay
IAP, Frankfurt am Main
IN2P3, Paris
INFN/LASA, Segrate (MI)
SCK-CEN, Mol
The goal of the MYRRHA project is to demonstrate the technical feasibility of transmutation in an Accelerator Driven System (ADS) by building a new flexible irradiation complex in Mol (Belgium). The MYRRHA facility requires a 600 MeV accelerator delivering a maximum proton flux of 4 mA CW operation. Such a machine belongs to the category of the high-power proton accelerators, with an additional requirement for exceptional reliability: because of the induced thermal stress to the subcritical core, the number of unwanted beam interruptions should be minimized down to the level of about 10 per 3-month operation cycle, a specification that is far above usual proton accelerators performance. This paper describes the reference solution adopted for such a machine, based on a so-called 'fault-tolerant' linear superconducting accelerator, and presents the status of the associated R&D.
TUB, Beijing
This paper will be generally reported that a new project of the Compact Pulsed Hadron Source (CPHS) led by the Department of Engineering Physics of Tsinghua University in Beijing, China. CPHS consists of a proton linac (13MeV, 16kW, Operating frequency 325MHz, peak current 50 mA, 0.5 ms pulse width at 50 Hz), a neutron target station (a Be target, moderators and reflector), and a small-angle neutron scattering instrument, a neutron imaging/radiology station, and a proton irradiation station. The linac accelerator is the main part of this project, which including a ECR ion source. LEBT section, a RFQ accelerator, a DTL linac and a HEBT An An experimental platform for further proton applications and more neutron beam lines will be added at a later stage. Currently, fabrication of the accelerator components has begun while the neutron target station, beam lines and instruments are under design study. The initial phase of the CPHS construction is scheduled to complete in the end of 2012.
LANL, Los Alamos, New Mexico
The Los Alamos Neutron Science Center (LANSCE) accelerator and beam delivery complex generates the proton beams that serve three neutron production sources, a proton radiography facility and a medical and research isotope production facility. The recent operating history of the facility, including both achievements and challenges, will be reviewed. Plans for performance improvement will be discussed, together with the underlying drivers for the ongoing LANSCE Life Extension project. The details of this latter project will also be discussed.
ITEP, Moscow
Intense heavy ion beam is very efficient tool to generate high energy density states in macroscopic amounts of matter. As result it enables unique methods to study astrophysical processes in the laboratory under controlled and reproducible conditions. For advanced experiments on high energy density physics the cylindrical target irradiated by hollow cylindrical beam is required. This combination provides extremely high densities and pressures on the axis of imploding cylinder. A new method for RF rotation of the ion beam is applied for required hollow beam formation. The RF system consisting of two four-cell H-mode cavities is under development for this purpose now. The cavities frequency has been chosen 298 MHz, which is sufficient for uniform target illumination at 100 ns pulse duration. The deflecting electrodes shape has been optimized to provide the uniform deflection of all particles in beam's cross-section. The prototype of the deflector cell was constructed. A measured electro-dynamics characteristic is presented. As well frequency corrections methods are considered in this paper.
FRIB, East Lansing, Michigan
NSCL, East Lansing, Michigan
The Facility for Rare Isotope Beams (FRIB) at Michigan State University will utilize a high power, heavy-ion linear accelerator to produce rare isotopes in support of a rich program of fundamental research. The linac will consist of a room temperature-based front-end system producing beams of approximately 0.3 MeV/u. Three additional superconducting linac segments will produce beams of >200 MeV/u with a beam power of up to 400 kW. Because of the heavy-ion beam intensities, the required diagnostics will be largely based on non-interceptive approaches. The diagnostics suites that will support commissioning and operation are divided into lower energy <0.3 MeV/u front-end and higher energy driver linac systems (<200 MeV/u for uranium). The instruments in the driver linac include strip-line BPM, toroid, BCM, and 3-D electron scanners to measure rms beam size. A desired availability of >90% and an aggressive commissioning schedule lead to some challenges in beam diagnostics requirements that will be addressed in this paper. We are committed to using an architecture common with the rest of FRIB for the data acquisition and timing which will also be discussed in this paper.
JAI, Egham, Surrey
CERN, Geneva
Compact Linear Collider (CLIC) is a multi-TeV electron-positron collider for particle physics based on an innovative two-beam acceleration scheme. The CLIC Test Facility 3 (CTF3, CERN) aims to demonstrate feasibility of this concept. The monitoring of a longitudinal profile will be very important for the CLIC. The optimization of the longitudinal charge distribution in a bunch is crucial for the maximisation of the luminosity and also for an optimal performance of a CLIC drive beam. A setup for the investigation of Coherent Diffraction Radiation (CDR) from targets with various configurations as a tool for non-invasive longitudinal electron beam profile diagnostics has been designed and installed in the CRM line of the CTF3 [1, 2]. In this report we present the status of the experiment and results on interferometric measurements of CDR from a single target configuration. Studies on downstream background contribution in the CRM line have been performed. Recently we have upgraded the system by installing a second target. In this report we shall also demonstrate the results on simulations of CDR spatial distribution from the two target configuration.
[1] M. Micheler et al., Longitudinal Beam Profile Measurements at CTF3 using CDR, PAC'09, "**".
[2] M. Micheler et al., Longitudinal beam profile monitor at CTF3 based on CDR, RREPS-09, "**".
PSI, Villigen
The SwissFEL Injector Test Facility consists of an RF gun, an accelerating section for a final energy of 250 MeV, and two diagnostics sections. Transverse profiles of the electron beam can be recorded at 27 locations by imaging fluorescent crystals that can be inserted into the beam. At 21 of these, the fluorescent screens are complemented by optical transition radiation monitors and wire scanners. Here, we will evaluate the performance of transverse profile monitors experimentally and numerically and compare the measured profiles with a numerical model of the accelerator. Profile monitors are used in conjunction with a slit and a pepper pot to determine the transverse phase space distribution of the bunches. Experimental measurements at the SwissFEL Injector Test Facility will be presented.
NSCL, East Lansing, Michigan
The US Department of Energy Facility for Rare Isotope Beams (FRIB) at Michigan State University includes a heavy ion superconducting linac capable of accelerating all ions up to uranium with energies higher than 200 MeV/u and beam power up to 400 kW. At an energy of approximately 17 MeV/u we plan to strip the beam to reduce the voltage needed in the rest of the linac to achieve the final energy. The design of the stripper is a challenging problem due to the high power deposited (approximately one kW) in the stripper media by the beam in the small beam size. One of the options being considered is a carbon foil stripper. We have developed a test chamber to study the thermal mechanical properties of different stripping media candidates (amorphous carbon, graphene, diamond). This chamber utilizes an electron beam to deposit powers similar to what the FRIB stripper will see in operation. The thermo-mechanical studies are a necessary condition but not sufficient. The effect of radiation damage must also be studied. We have utilized heavy ions (Pb) from the K500 cyclotron to study this issue. We present in this paper a summary of the requirements and the status of the studies.
Fermilab, Batavia
UCR, Riverside, California
IIT, Chicago, Illinois
Illinois Institute of Technology, Chicago, Illinois
Muon ionization cooling provides the only practical solution to prepare high brilliance beams necessary for a neutrino factory or muon colliders. The muon ionization cooling experiment (MICE) is thus a strategic R&D project for neutrino physics. It is under development at the Rutherford Appleton Laboratory (UK). It comprises a dedicated beam line to generate a range of input emittance and momentum, with time-of-flight and Cherenkov detectors to ensure a pure muon beam. A first measurement of emittance is performed in the upstream magnetic spectrometer with a scintillating fiber tracker. A cooling cell will then follow, alternating energy loss in liquid hydrogen and RF acceleration. A second spectrometer identical to the first one and a particle identification system provide a measurement of the outgoing emittance. In the 2010 run, completed in August, the beam and most detectors have been fully commissioned. The time of the first measurement of input beam emittance is closely approaching. The plan of steps of measurements of emittance and emittance reduction (cooling), that will follow in 2011 and later, will be reported.
I submit this as chair of the MICE speakers bureau. If accepted, I will find a member of the collaboration that will register to the conference and present the contribution.
ORNL, Oak Ridge, Tennessee
This talk will give an overview of future demands of fast choppers with fast rise/fall time to reduce the beam extinction ratio further.
KEK, Ibaraki
The KEK injector linac sequentially provides beams to four storage rings: a KEKB low-energy ring (LER) (3.5 GeV/positron), a KEKB high-energy ring (HER) (8 GeV/electron), a Photon Factory ring (PF ring; 2.5 GeV/electron), and an Advanced Ring for Pulse X-rays (PF-AR; 3 GeV/electron). So far, beam injection to the PF ring and PF-AR had been carried out twice a day, whereas the KEKB rings had been operated in the continuous injection mode (CIM) for keeping stored currents almost constant. The KEK linac upgrade project has started since 2004 so that the PF top-up and KEKB CIM can be operated at the same time. The goal is to inject the beams of different energy into the three independent rings in every 20 ms, where the common DC magnet settings are utilized for beams having different energy and charge, whereas different optimized rf phases are applied to each beam acceleration by using a fast low-level rf control up to 50 Hz. With this noble operation scheme, a simultaneous top-up operation for different three rings was achieved for the first time over the world, and has been stably in operation since last April. We report the operation scheme and status in detail.
IAP, Frankfurt am Main
The Frankfurt Neutron source FRANZ is under construction*. The ARMADILLO bunch compressor** as a part of it is composed of a 5MHz electric kicker, a magnetic dipole chicane and rf-rebunching cavities. The design phase of the bunch compressor has reached the final stage. A 175MHz 2MeV proton linac forms 100ns long beam pulses consisting of nineμbunches with 150mA. Deflected by the 5MHz kicker theμbunches are guided on different paths to arrive within 1ns at a n-production target. Due to high space charge forces rebuncher cavities are included***. The peak current at the target is expected to be in the range of 10A in a 1ns proton pulse, which is equivalent to a longitudinal pulse compression ratio of 45. A new code specific for complex magnetic multi aperture system and for high current applications has been developed. Hardware designs according to the beam dynamics results are in progress. Improved 3D magnetic and electric fields will be applied in the future beam dynamics studies including high space charge forces. The preliminary designs and the beam dynamics studies will be presented in this contribution.
LANL, Los Alamos, New Mexico
The Dual-Axis Radiographic Hydrodynamic Test Facility (DARHT) at Los Alamos National Laboratory consists of two linear induction accelerators at right angles to each other. The First Axis, operating since 1999, produces a nominal 20-MeV, 2-kA single beam-pulse with 60-nsec width. In contrast, the DARHT Second Axis, operating since 2008, produces up to four pulses in a variable pulse format by slicing micro-pulses out of a longer 1.6-microseconds (flat-top) pulse of nominal beam-energy and -current of 17 MeV and 2 kA respectively. Bremsstrahlung radiation, shining on a hydro-dynamical experimental device, is produced by focusing the electron beam-pulses onto a high-Z target. Variable pulse-formats allow for adjustment of the pulse-to-pulse doses to record a time sequence of x-ray images of the explosively driven imploding mock device. In this talk, we present a sampling of the numerous physics and engineering challenges encountered and the solutions thereof that led to the present fully operational dual axes capability. First successful simultaneous use of both the axes for a hydrodynamic experiment was achieved in 2009.
Diamond, Oxfordshire
Ultrashort electron beams can be used for investigating ultrafast dynamics of physical, chemical or biological systems. With an S-band photocathode gun, simulations have been done in order to generate ultrashort electron beams. Optimizations to generate ultrashort electron beams with a small beam divergence and to minimize the system sensitivity against RF jitter are reported.
IHEP Beijing, Beijing
KEK, Ibaraki
IHEP Beiing, Beijing
The combination of the low-loss shape and large grain niobium material is expected to be the possible way to achieve higher gradient and lower cost for ILC 9-cell cavities. As the key component of the 'IHEP 1.3 GHz SRF Accelerating Unit and Horizontal Test Stand Project', a low-loss shape 9-cell cavity using Ningxia large grain niobium (IHEP-01) was fabricated and surface treated (CBP, CP, annealing, pre-tuning) at IHEP. Then the cavity was shipped to KEK STF for ultrasonic cleaning, high pressure rinsing, baking and vertical test. The cavity reached 20 MV/m in the first vertical test on July 1st 2010. The quench location has been found by T-mapping and optical inspection. The strong field emission and equator defects will be removed by further treatment. The fabrication procedure, surface treatment recipes and the first test results are summarized in this paper.