LBNL, Berkeley, California
At LBNL in Berkeley, clinical trials were conducted (1975-1992) for treating human cancer using ion beams from the Bevalac and treated about 700 patients with helium-ion and about 300 patients with neon-ion beams.* Clinical trials (1997-2005) at GSI in Darmstadt, Germany used carbon-ion beams to treat about 250 patients. In 1994, NIRS in Chiba, Japan, commissioned its first-in-the-world ion-beam therapy facility, HIMAC, which accelerates ions as heavy as argon nuclei to 800 MeV/nucleon. Following it, several carbon-ion therapy facilities have been, or will be soon, constructed in: Hyogo (2001) and Gunma (2010), Japan; Heidelberg (2009), Marburg (2010) and Kiel (2012), Germany; Pavia (2010), Italy; Lyon (2013), France; Wiener Neustadt (2013), Austria; Shanghai and Lanzhou, China; and Minnesota and California, USA. Technical specifications of these facilities are: ion sources delivering all ion species from proton to carbon, accelerator energy of 430 MeV/n (30-cm range in tissue), beam intensity of about 109 pps (to deliver 1 Gy/min into 1-liter volume), repetition rate of about 0.5 Hz with long spill (for beam scanning), and treatment beam delivery and patient safety systems.
* Castro, JR, "Future research strategy for heavy ion radiotherapy," in Progress in Radio-Oncology (ed. Kogelnik, H.D.), Monduzzi Editore, Italy, 643-648 (1995).
Siemens Med, Erlangen
Siemens DK, Jyllinge
FRIB, East Lansing, Michigan
Siemens has earned three contracts to deliver IONTRIS Particle Therapy accelerator systems* to be operated in Marburg and Kiel, both in Germany, and in Shanghai, China. The accelerator part consists of an injector (7 MeV/u protons and light ions) and a compact synchrotron able to accelerate proton beams up to 250 MeV and carbon ions up to 430 MeV/u. These beams can be slowly extracted and delivered to a choice of fixed-angle horizontal, semi-vertical and vertical beam-ports. An overview of the design will be given and the status of the installation and commissioning work for the first two projects will be shown.
*Particle Therapy is a work in progress and requires country-specific regulatory approval prior to clinical use.
HIT, Heidelberg
Since November, 15th 2009 patients are treated with protons and carbon ions at the Heidelberg Ionbeam Therapy Centre (HIT). The facility - two ion sources, an injector linac and a compact synchrotron - is operated in 24/7-mode with high availability. The HIT beam time schedule is discussed along the statistics automatically generated by the control system. Besides the patient treatment in the first horizontal room beam time is also used to develop enhanced treatment software in the second horizontal room as well as for commissioning the gantry place. Additionally, biophysics studies are served at a separate experimental place. In parallel, an upgrade program for the accelerator is under way: at first a test bench for a third ion source, later on dedicated to He beams, will be used to study several ideas to increase the injector performance. Furthermore operation mechanisms are under progress to control directly the synchrotron dipole and quadrupole fields as well as to regulate the spill structure - the aim of both developments is to form a uniform and extremely stable extracted beam with high duty cycle. An overview on this entire accelerator R&D at HIT will be given.
NIRS, Chiba-shi
Construction of new treatment facility as an extension of the existing HIMAC facility, in which all treatment room will be equipped with a 3D pencil beam scanning system, is in progress at NIRS. The challenge of this project is to realize treatment of a moving target by scanning irradiation, because pencil beam scanning is more sensitive to organ motions compared with the conventional broad-beam irradiation. To accomplish practical moving target irradiation, a prototype of the scanning irradiation system was constructed and installed into existing HIMAC physics experiment course. One of the most important features of the system to be tested is fast scanning toward moving target irradiation with a relatively large number of rescannings within an acceptable irradiation time. Commissioning of the prototype is successfully in progress cooperating with highly stabilized beam provided by the HIMAC accelerator complex. We will report the design of the system and the status of the beam study.
NIRS, Chiba-shi
AEC, Chiba
Tumor therapy using energetic carbon ions, as provided by the HIMAC, has been performed since June 1994, and more than 5000 patients were treated until now. With the successful clinical results over more than ten years, we are constructing a new treatment facility. The new facility would have three treatment rooms; two of them have both horizontal and vertical fixed-irradiation-ports, and the other has a rotating-gantry-port. For all the ports, a scanning irradiation method is applied. The new facility is constructed in conjunction with the HIMAC, and heavy-ion beams will be provided by the HIMAC accelerators. To fulfill requirements for the scanning irradiation, we proposed multiple-energy operation with the quasi-DC extension of a flat top. With this operation, the beam energy can be successively varied within a single synchrotron-cycle, and therefore no energy degrader or the range shifter is required. The beam acceleration and extraction tests of the multiple-energy operation were successfully made. We will present the development of this operation as well as results of the beam acceleration tests.
CERN, Geneva
EBG MedAustron, Wr. Neustadt
MedAustron is a synchrotron based accelerator facility for cancer treatment in Austria currently in the development phase. The design is based on the PIMMS study* and CNAO** synchrotron. In addition to the clinical application, the accelerator will also provide beams for nonclinical research in the fields of medical radiation physics, radiation biology and experimental physics with an extended proton energy range beyond medical requirements to 800 MeV. The differences to others medical accelerator-based facilities will be elaborated, specifically the used source technologies and configuration (starting up with protons (p) and carbon ions (C6+) allowing a later upgrade to ion species up to neon) and the online verification of all relevant beam parameters. The current project status is presented.
* PIMMS Proton-ion medical machine study, Bryant, Philip J (ed.) et al., CERN, 2000.
** CNAO, www.cnao.it
The University of Tokyo, Nuclear Professional School, Ibaraki-ken
JAEA, Ibaraki-ken
UTNL, Ibaraki
Dual energy X-ray system using high energy X-ray from linear accelerator (Linac) applies two times X-ray irradiation which have different energy spectrum each other in many cases. Two different X-rays yield two tomography images which is analyzed through numerical calculation with pixel values for material recognition of a object. However if the X-ray generation is not stable, the results of numerical calculation shows irregular tendency during the inspection. We propose the scintillator array in detection part, because two tomography images are obtained by just one irradiation. That leads to the time saving during inspection and the cost down for additional facilities. The optimal condition is researched to increase the ability of material recognition in interesting materials designing the detector with CsI and CdWO4 scintillators. We focus on the discrimination between heavy materials and light materials with the system in the research. X-ray source is 950 keV X-band Linac we developed for industrial application, which produce pulsed X-ray, 10 pps with around 400 mA beam current.
Osaka Prefecture University, Sakai
The coherent synchrotron and transition radiation from the bunched electron beams of a linear accelerator (linac) has continuous spectra in a submillimeter to millimeter wavelength range at relatively high peak-intensity. The coherent radiation has been applied to absorption spectroscopy for various kinds of matters. However, the number of such light sources are very small. A new pulsed coherent transition radiation light source has been established by using the electron beams of a 18 MeV S-band electron linac at Osaka Prefecture University (OPU). In the linac pulsed electron beams are injected from a thermionic triode gun with a cathode-grid assembly at pulse lengths of 5 ns-4 μs at a pulse repetition rate of 500 pulses/s in maximum. The light source will be also applied to the pump-probe experiment using the pulsed electron beam or the pulsed coherent radiation as a beam for pumping matters and the coherent radiation for probing them. The transient properties of the matters excited with the electron beams or the coherent radiation will be investigated. The characteristics of the light source are reported.
KURRI, Osaka
University of Fukui, Faculty of Engineering, Fukui
In Kyoto University Research Reactor Institute (KURRI), The FFAG accelerator complex for accelerator driven sub-critical reactor (ADSR) project has been already constructed and world first ADSR experiment has been done at May, 2009. In the main ring, proton beams of 11.5 MeV are injected and accelerated up to 100 MeV. During the acceleration, two different types of beam loss have been observed. To investigate these beam loss, betatron and synchrotron motion have been measured experimentally. The details of measurements will be described in this presentation.
ESRF, Grenoble
IPN, Orsay
LPSC, Grenoble
GANIL, Caen
Laboratoire de Physique des Gaz et des Plasmas, Universite Paris-Sud, Orsay
SOLEIL, Gif-sur-Yvette
CEA, Gif-sur-Yvette
SDMS, Saint Romans
LAL, Orsay
The French Physics Society is an association the purpose of which is to promote physics and physicists. In this context, the accelerator physics and associated technology division is in charge of the promotion of accelerator activities in France. This paper presents the missions and actions of the division, highlighting those concerning young scientists. A brief presentation of the laboratories, institutes or facilities who are the main actors in the field will then be given. Significant projects which are underway or planned will be described, including medical applications. The major contribution of France to international projects will then be introduced. Finally the cultural and technical relations between industry and laboratories will be discussed.
KEK, Ibaraki
TIT, Tokyo
Japan Proton Accelerator Research Complex (J-PARC) requires thick carbon stripper foils (200-500 ug/cm2) to strip electrons from the H- beam supplied by the linac before injection into the Rapid Cyclic Synchrotron. A H- beam of 181MeV energy is injected into the 3 GeV Rapid Cycling Synchrotron (RCS) with a pulse length of 0.5 ms, a repetition rate of 25 Hz, and an average beam current of 200 μA. The H- ions are stripped into protons by a charge stripper foil in the injection section. For this high-energy and high-intensity beam, the conventional carbon stripper foils will be ruptured in a very short time. Thus, long-lived thick carbon stripper foils are needed to this high-power accelerator. For this purpose, we are described R and D of long-lived Hybrid Boron-mixed Carbon foils (HBC-foils) of 100 - 500 μg/cm2 by arc discharge method. The preparation procedure is described and lifetime measurement by using a 3.2MeV Ne+ DC beam of 2-3 μA are reported.
GUAS, Kanagawa
KEK, Ibaraki
Tsukuba University of Technology, Kasuga Campus, Tsukuba, Ibaraki
Japanese research to build accelerators for high energy physics started with Electron Synchrotron at Institute of Nuclear Study, Tokyo (INS). The development was slow in the beginning, in particular before the construction of KEK-PS. After the experience of TRISTAN, KEKB, one of the best colliders in the world, was eventually constructed. We will review the history of high energy accelerators in Japan from physics, technological and particularly social points of view referring to documents at KEK and other archives. This is the first of a series of papers and will outline the over-all view.
National Chiao Tung University, Hsinchu
NTHU, Hsinchu
NSRRC, Hsinchu
Resonant transition radiation (RTR) driven by a femtosecond electron beam is being studied. An aluminum foil stack with vacuum spacers is used as the radiator. With a 27 MeV electron bunch with pulse duration at ~ 100 fsec incident normally on the aluminum foil stack, high photon yields in hard X-ray regime can be obtained. Characteristics of the radiation such as emission spectrum, spatial distribution are calculated. The dependence of RTR photon yields on beam size and bunch length are also studied.
CNAO Foundation, Milan
CERN, Geneva
LPSC, Grenoble
INFN/LNF, Frascati (Roma)
CNAO is a synchrotron accelerator presently under commissioning in Pavia. The aim of this accelerator is to treat tumors with hadrons and to perform advanced clinical and radiobiological research. The CNAO will start treating patients with protons (60-250 MeV range) and carbon ions (120-400 MeV/u range) in three treatment rooms with four beam lines. Future upgrade with gantries is foreseen. This paper describes the design, magnetic measurements and sorting criterion used for the sixteen synchrotron main dipoles and twenty-four quadrupoles. The magnetic measurements results are compared with magnetic simulation.
CNAO Foundation, Milan
The National Centre for Oncological Hadrontherapy (CNAO) will be the first Italian facility for the treatment of deep located tumours with proton and carbon ion beams and active scanning technique. The accelerator complex consists of an injection system, a synchrotron and 5 extraction lines. By the end of 2009 the ECR sources, Low Energy Transfer Line (LEBT), RFQ and LINAC where fully commissioned; in December injection and first turns in the synchrotron were also successfully achieved. Full installation of machine and extraction lines was completed in early 2010. The recent advances in the commissioning and performance of the CNAO complex are being reported in this contribution.
Hiroshima University, Graduate School of Science, Higashi-Hiroshima
HSRC, Higashi-Hiroshima
The HiSOR-II is a storage ring planned as a successive machine of HiSOR, a present ring at Hiroshima Synchrotron Radiation Center. This accelerator has the circumference equal to or less than 50 m, and it has the emittance about 14 nm-rad and aims at the beam energy of 700 MeV. In the HiSOR-II project, we decided to adopt electromagnets with combined function. This type magnet has an advantage for constructing a small storage ring by reducing the total number of magnet, though it has a difficulty for the independent tuning of multipole field components. In addition, we decided to share a single return yoke between a bending magnet and adjacent quadrupole magnets. In this paper, we discuss about a possible magnetic interference between a bending magnet and a quadrupole magnet. Calculation is made with magnetic field simulation cord RADIA to analyze interference effect and examine the possibility of adoption to HiSOR-II storage ring. Also, we perform the tracking simulation of the beam with the mapping data of a magnetic field provided by this three-dimensional magnetic field analysis. By the simulation, the dynamic aperture is determined.
CERN, Geneva
EBG MedAustron, Wr. Neustadt
At CERN, the control of five of the accelerators in the injector chain (i.e. PS, PS Booster, SPS, LEIR and AD) is based upon real-time magnetic measurements in a reference magnet. These systems ("B-trains") include usually a field marker to signal the achievement of a given field value, complemented by one or more pick-up coils to integrate flux changes. Recently, some issues have been raised concerning long-term reliability and possible performance improvements, in terms of both resolution and operational flexibility, for these systems. This paper reports the results of R&D activities launched to address these concerns, namely: the development of a novel ferrite gradient compensator to enable dynamic NMR field marking in the PS' combined function magnets; and the preliminary design of a standardized electronic acquisition and conditioning system aimed at enabling the requested improvements and at facilitating rapid maintenance interventions.
NSRRC, Hsinchu
Taiwan Photon Source (TPS) is a new third generation synchrotron storage ring with energy 3 GeV, which consists of 24 double-bend cells and its circumference is 518.4 m. Various accelerator lattice magnets which consist of 48 bending magnets, 240 quadrupoles and 168 multifunction sextupole magnets. All magnets pole profiles, edge shim and magnet end chamfer were designed in TOSCA and RADIA magnetic computation code. In order to verify the magnetic field quality of computation code, prototype magnets have been manufactured in this year. Two measurement systems, hall probe and rotating coils, were used for magnetic field mapping. This paper presents magnetic field mapping results of prototype magnets and compared with original magnetic circuit designs.
NSRRC, Hsinchu
A magnet array of superconducting undulator SU15, with 130 poles and length 0.98 m, was constructed, and the field measurement and training are also performed at National Synchrotron Radiation Research Center (NSRRC). The NbTi wires were excited to 1.36 T @ 497 A after 28 times quench. A cryogenic Hall probe (length 2500 mm) was used to characterize the distribution of the magnetic field of magnet arrays in the 5.6-mm magnetic gap. The measurement region of the cryogenic Hall probe is greater than 1200 mm in the vertical dewar. The length shrinkage or expansion of the Hall probe depends on the thermal variation at both ends of the Hall probe. The length of the Hall probe will be evaluated in the field measurement region. The reproducibility of the measurement system was verified in the same experiment. A field shimming method involving a trim iron piece was used to correct for deviations of the magnetic field. This paper discusses the measurement accuracy in the cryogenic Hall probe system and presents results of the field shimming.
Hitachi Ltd., Ibaraki-ken
Hitachi, Ltd., Power & Industrial Systems R&D Laboratory, Ibaraki-ken
SAGA, Tosu
A 4T superconducting wiggler for 1.4GeV synchrotron radiation facility Saga Light Source (SAGA-LS) was developed and manufactured. The wiggler consists of one superconducting magnet as main-pole and two normal conducting magnets as side-poles. The superconducting coils are wound with NbTi wires on iron poles, which are directly cooled by a 2-stage GM cryocooler. The structure of the wiggler is made for compactness and cryogen-free operation. This paper describes its magnet design and manufacturing processes.
Air Liquide, Division Techniques Avancées, Sassenage
F4E, Barcelona
STFC/RAL/ISIS, Chilton, Didcot, Oxon
ANSTO, Menai, New South Wales
Thanks to its experience in past projects in the field of neutron sources, Air Liquide DTA was involved in recent years in two major projects : a new Cold Neutron Source (OPAL) at ANSTO, Australia and a Spallation Neutron Source at ISIS, United Kingdom. The OPAL CNS is a liquid deuterium moderated source operating with a cold box with a refrigeration capacity of 5 kW at 25K designed and manufactured by Air Liquide DTA. ISIS Target Station 2 is a liquid hydrogen and solid methane moderated source for which Air Liquide DTA provided two Helium cold boxes (about 600W) operating at 20K derived from the standard Helial product, one customised cryogenic hydrogen loop, and very specific remote dismountable cryogenic transfer lines. These two cryogenic systems were fully commissioned on Air Liquide DTA dedicated test area before delivery to the customers. The purpose of this paper is to give a compared overview of the design and testing of the proposed cryogenic systems for these two projects.
SLAC, Menlo Park, California
LBNL, Berkeley, California
CERN, Geneva
CEA, Gif-sur-Yvette
Lancaster University, Lancaster
We present results from the measurement of the 3-D luminosity distribution with the ATLAS Inner Detector during early running. The spatial distribution of pp interactions is reconstructed by a dedicated algorithm in the High-Level Trigger that fits tracks and primary event vertices in real time, and by an offline algorithm that takes full advantage of the high tracking efficiency and resolution. The number of vertices provides online monitoring of the instantaneous luminosity, while luminous-centroid motion mirrors IP-orbit and RF-phase drifts. The x, y and z luminous widths reflect the evolution of the transverse and longitudinal emittances. The length scales of the IP orbit bumps, which directly impact the accuracy of the transverse convolved beam sizes measured during van der Meer scans, are calibrated offline against the measured displacement of the luminous centroid; this significantly improves the accuracy of the absolute luminosity calibration. The simultaneous determination, during such scans, of the transverse convolved beam sizes (from the luminosity variation) and of the corresponding luminous sizes can be used to disentangle the transverse IP sizes of the two beams.
CERN, Geneva
SLAC, Menlo Park, California
Fermilab, Batavia
Unbunched beam is a potentially serious issue in the LHC as it may quench the superconducting magnets during a beam abort. Unbunched particles, either not captured by the RF system at injection or leaking out of the RF bucket, will be removed by using the existing damper kickers to excite resonantly the particles in the abort gap. Following beam simulations, a strategy for cleaning the abort gap at different energies was proposed. The plans for the commissioning of the beam abort gap cleaning are described, and the first results from the beam commissioning are presented.
STFC/RAL/ASTeC, Chilton, Didcot, Oxon
The lattice of a Fixed Field Alternating Gradient (FFAG) accelerator normally has high symmetry. The whole ring consists of many identical cells which have a simple FODO, double or triplet focusing unit. There is, however, no real reason for an FFAG lattice to have high symmetry, except for a linear nonscaling design which relies on high symmetry to avoid betatron resonances. We propose an FFAG lattice design with a superperiod that makes it possible to have long straight sections for injection, extraction and rf cavities. We discuss how to introduce a superperiod structure. The impact on dynamic aperture, dispersion function, longitudinal dynamics as well as the advantage of having long straight sections will be presented.
KEK, Ibaraki
SAMEER, Mumbai
Tokyo City University, Tokyo
The KEK-DA (Digital Accelerator) is a modification of the KEK 500 MeV booster*, in which an induction acceleration system is employed. It has an ability to accelerate arbitrary ions with their possible charge states**. An outline of the acceleration scenario is described and a necessary control system fully integrating the induction acceleration system is given in details. The KEK-DA is a rapid cycle synchrotron operating at 10 Hz; the accelerating pulse voltage must be dynamically varied in time to follow the ramping magnetic field. A novel technique combining the pulse density control and intermittent operation of acceleration cells is required. The intelligent gate control system which uses 1 GHz digital signal processors (DSPs) has been designed. Construction of the KEK-DA is in the final stage; installation of the induction cells and the power supplies are done. The whole system including gate control system is demonstrated with high voltage outputs,long-term stability of the system through a heat run is examined. Also a future plan which replaces DSPs by FPGA (Field Programmable Gate Array)is discussed.
* K.Takayama et al., JOURNAL OF APPLIED PHYSICS 101, 063304 (2007).
** K.Takayama et al., "KEK Digital Accelerator for Material and Biological Sciences" in this conference.
KEK, Ibaraki
STFC/RAL/ISIS, Chilton, Didcot, Oxon
ANL, Argonne
Tsukuba University, Ibaraki
A low-output-impedance RF system for the second harmonic cavity in the ISIS synchrotron has been developed by collaboration between Argonne National Laboratory (US), KEK (Japan) and Rutherford Appleton Laboratory (UK). The system has less than 30 Ω of output impedance over wide frequency range of 2.7-6.2 MHz. However, distortions of voltage waveform in the driver stage have been a long-standing issue. It was found such distortions were generated depending upon the higher-order-modes of the anode-choke impedance. In this report, method to realize the smooth sinusoidal waveform in the wideband system is presented.
KEK, Ibaraki
The J-PARC accelerator complex consists of a linear accelerator (330 m long, 181 MeV), a rapid cycling synchrotron (3 GeV RCS, 350 m circumference, 25 Hz) and a slow cycling synchrotron (MR, 30 GeV as a first step energy, 1600 m circumference, typically with 3.5 sec cycle). The RCS provides high intensity proton beam to the materials and life science facility and the MR. The MR has two beam extraction lines. One is a slow extraction system for the hadron physics, and other a fast extraction system for neutrino science. We have to challenge many issues to complete construction of the J-PARC accelerator facility on-schedule in 2008 despite all the hardships, such as the problems included in the original design, technology choices and fabrication procedure of the machine components, and construction of conventional facilities. As a first step of operation, we could commission all accelerator facilities and provide beam to all experimental facilities in 2009 successfully. We will report about analysis of these issues and how to solve them, which is a necessary step to realize the design beam power as a next step, and to challenge the future upgrade beyond the original design.
KEK/JAEA, Ibaraki-Ken
KEK, Ibaraki
JAEA/J-PARC, Tokai-mura
The Japan Proton Accelerator Complex includes the 3GeV rapid cycling synchrotron (RCS) and the 50GeV main ring synchrotron (MR). Both synchrotrons use the high field gradient magnetic alloy (MA) loaded cavities. In RCS, 11 RF systems have been fully operational since December 2008. The RCS RF systems are operated with dual-harmonic acceleration voltages. Beam acceleration and bunch shape manipulation are efficiently taking place. 120kW of the neutron user operation was started at the Material and Life science facilities in November 2009. In MR synchrotron, the 5th RF system were installed in August 2009, and therefore 5 RF systems are now in operation. Beam commissioning for delivering protons to the hadron facility and neutrino beam experimental facility are under way. The neutrino user experiment is intended to start January 2010. Proton beam operation with more than 100kW is required. The approaches to realizing high intensity operation and the MR upgrade plan will be presented.
HIT, Heidelberg
While ramping the magnets in a synchrotron the magnetic fields deviate from their set values. Especially the field errors in dipole and quadrupole magnets result in different problems during operation. At the Heidelberg Ion Therapy Center HIT a measuring system with extremely high precision has been developed. It can measure in real time integral magnetic fields with a precision of better than 5*10-5 in a reproducible way. A feed-back control system for the magnetic fields is being installed and will be operational in May 2010. This control loop lets the magnets reach the nominal field much faster and thus shortens the dead time in a synchrotron cycle. The cycle can be reduced by 30% and more patients can be treated.
KAERI, Daejon
BNL, Upton, Long Island, New York
As a feasible extension plan of the proton engineering frontier project (PEFP) 100-MeV proton linac, the conceptual design of an rapid cycling synchrotron (RCS) is under progress. The main purpose of the synchrotron is a spallation neutron source and it also includes the slow extraction option for basic and applied science research. In the initial stage, the beam power is 60 kW by using a scheme of 100-MeV injection and 1-GeV extraction. There is a scheme to increase power to 500 kW through a 3-stage upgrade. The injection and extraction energies will be 200-MeV and 2-GeV respectively after the final upgrade. This article summarizes the present status of the RCS design. It includes the physics design including injection and acceleration, and conceptual design of some magnets and RF cavity.
WERC, Tsuruga , Fukui
We have operated the accelerator system which consists of a tandem accelerator and a synchrotron since the completion of the construction and beam commissioning at the Wakasa-wan Energy Research Center, Tsuruga, Japan in 2000. The acceleration voltage of the tandem accelerator amounts to 5 MV and is generated by the Dynamitron-type cascade voltage doubler rectifier. The beam from the tandem accelerator is transported to the MeV-ion experimental area for the irradiation to the industrial or biological material and for the ion beam analysis. The tandem beam is also injected to the 200 MeV proton synchrotron. The synchrotron beam has been used for the high energy irradiation and the cancer therapy. The tandem accelerator is used for a lot of purposes including cancer therapy, therefore, stable operation of the system and efficient sharing of the operation duration are required. Developments of the accelerator are presented putting a stress on the stable and efficient operation of the system in this paper.
GSI, Darmstadt
This paper describes the development of a new rf accelerating cavity based on novel magnetic alloy materials (MA-materials) for operation at harmonic number h=2 (f=0,43- to 2,8 MHz) to provide the necessary accelerating voltage for SIS18 injector operation with high intensity heavy ion beams in a fast operation mode with three cycles per second. The acceleration system consist of three units which are able to operate independently from each other. That is important, since each ion for FAIR has to cross the h=2-rf-system and in the case of a damage a reduced operation has to be ensured. Since the cavities are filled with lossy MA-ring-cores, which are iron based Finemet FT3M ring cores from Hitachi, the cavities show a broadband behaviour and thus no cavity tuning during the acceleration ramp will be necessary. Due to the high saturation field strength of Finemet (1,2 T) the overall length of all three cavity units can be very short. This is an important feature since due to many insertions which were additionally inserted into the synchrotron ring SIS12/18 in the meantime, the available length in SIS12/18 for the cavity units is with 4 m very short.
FZJ, Jülich
GSI, Darmstadt
Numerical studies of longitudinal filter and time-of-flight (TOF) cooling suggest that the strong mean energy loss due to an internal Pellet target in the High Energy Storage Ring (HESR) at the FAIR facility can be compensated by cooling and operation of a barrier bucket (BB) cavity. In this contribution detailed experiments at COSY to compensate the mean energy loss are presented. The internal Pellet target was similar to that being used by the PANDA experiment at the HESR. A BB cavity was operated and either TOF or filter stochastic momentum cooling was applied to cool a proton beam. Experimental comparisons between the filter and TOF cooling method are discussed. Measurements to determine the mean energy loss which is used in the simulation codes are outlined. The experiments proved that the mean energy loss can be compensated with a BB cavity. Results are compared with numerical tracking simulations which include the synchrotron motion in a barrier bucket as well as in an h = 1 cavity and stochastic momentum cooling. A detailed discussion of the tracking simulation code will be outlined in a separate contribution to this conference.
Kyoto ICR, Uji, Kyoto
MPI-K, Heidelberg
Kyoto IAE, Kyoto
HU/AdSM, Higashi-Hiroshima
NIRS, Chiba-shi
JINR, Dubna, Moscow Region
Experiments of transverse laser cooling for 24Mg+ beam have been performed at the small ion storage and cooler ring, S-LSR. It is predicted that the longitudinal cooling force is transmitted to the horizontal direction with synchro-betatron coupling at the resonant condition*. The laser system consists of a 532nm pumping laser, a ring dye laser with variable wavelength around 560nm, and a frequency doubler. The horizontal beam size and the longitudinal momentum spread were optically measured by a CCD and a PAT (Post Acceleration Tube) respectively**, ***. The CCD measures the beam size by observing spontaneous emission from the beam and records in sequence of 100ms time windows the development of the beam profile. The time variation of the beam size after beam injection indicates the transverse cooling time. The initial horizontal beam size, which was about 1mm, was decreased by 0.13mm in 1.5s. The longitudinal momentum spread measured by PAT is increased at the resonant condition. This suggests transverse temperature was transferred to longitudinal direction by synchro-betatron coupling. Both measurements denote the horizontal cooling occurred only in the resonant condition ****.
* H. Okamoto, Phys. Rev. {E50}, 4982 (1994)
** M. Tanabe et. al, Appl. Phys. Express 1 (2008) 028001
*** T. Ishikawa Master Thesis, Kyoto Univ.(2008)
**** H. Souda et. al., contribution to IPAC10.
Kyoto ICR, Uji, Kyoto
MPI-K, Heidelberg
Kyoto IAE, Kyoto
HU/AdSM, Higashi-Hiroshima
NIRS, Chiba-shi
JINR, Dubna, Moscow Region
Transverse laser cooling with the use of a synchro-betatron coupling is experimentally demonstrated at the ion storage/cooler ring S-LSR. Bunched 40keV 24Mg+ beams are cooled by a co-propagating laser with a wavelength of 280nm. Synchrotron oscillation and horizontal betatron oscillation are coupled by an RF drifttube at a finite dispersive section (D = 1.1m) in order to transmit longitudinal cooling force to the horizontal degree of freedom*. Time evolution of horizontal beam size during laser cooling was measured by a CCD camera**. Horizontal beam sizes were reduced by 0.13mm within 1.5s after injection when the tune values satisfy a difference resonance condition, νs - νh = integer, at the operating tunes of (νh, νv, νs)=(2.067, 1.104, 0.067) and (2.058, 1.101, 0.058). Without resonance condition, the size reduction was negligibly small. The momentum spread was 1.7x10-4 on the resonance otherwise 1.2x10-4. These results show that the horizontal heats are transferred to the longitudinal direction through the synchro-betatron coupling with the resonance condition and are cooled down by a usual longitudinal bunched beam laser cooling.
* H. Okamoto, Phys. Rev. E 50, 4982 (1994).
** M. Nakao et. al., contribution to this conference.
YerPhI, Yerevan
The Vibrating Wire Monitor (VWM) with aperture 20 mm was developed for scan of electron beam with large transversal sizes. Test experiments with VWM placed in air were done on the 20 MeV electron beam of Yerevan Synchrotron Injector with 4-7 uA at outlet. A new design of VWM is proposed for scan of the beam with even greater transversal sizes.
Monash University, Faculty of Science, Victoria
ASCo, Clayton, Victoria
A new arrangement for the synchrotron radiation interferometer was proposed - as far as is known, it is unique in the world. The Young's-type interferometer is composed of two independent and optically identical paths, each with a single slit on a motorised translating stage. These two single slit patterns are interfered to produce a double slit diffraction pattern. This arrangement permits rapid scanning of the profile of fringe visibility as a function of slit separation. The interferometer was used on two beamlines at the Australian Synchrotron, the optical diagnostic and infrared beamlines. The interferometer was used to measure the coherence of the photon beam created by the electron beam source, for normal and low emittance couplings. A large change in fringe visibility was observed, proving the experimental arrangement. The interferometer was validated in the measurement of the width of a hard-edged single slit, akin to Thompson and Wolf's diffractometer. Optical simulations and measurements inform proposed modifications to the optical diagnostic beamline, so as to implement the interferometer as a regular diagnostic tool.
ASCo, Clayton, Victoria
Thirty two Bergoz Beam Position Monitors are located in the Australian Synchrotron booster ring. They currently suffer from a poor signal-to-noise ratio and a low sample rate data acquisition (DAQ) system, provided by a portable DAQ device. This architecture is being upgraded to offer better performance. Phase matched low attenuation cables are being pulled and readout electronics will be located in two sites to reduce cable length. Data acquisition will be upgraded using a high accuracy PCI DAQ board. The board's trigger, originally delivered by a Delay Generator, will be generated by an Event Receiver output following our recent upgrade of the timing system. The new Linux driver will be EPICS-based, for consistency with our control system.
ELSA, Bonn
At the electron stretcher accelerator ELSA of Bonn University, an external beam of either unpolarized or polarized electrons is supplied to hadron physics experiments. In order to correct dynamic effects caused by eddy currents induced during the fast energy ramp, the transversal tunes have to be measured in situ with high precision. These measurements are based on the excitation of coherent betatron oscillations generated by a pulsed kicker magnet. Horizontal oscillations were excited using one of the injection kicker magnets. Since its installation in 2009 a newly designed kicker magnet enables measurements in the vertical plane as well. Betatron oscillation frequencies were derived from a fast Fourier transform of the demodulated BPM signals, showing a well pronounced peak at the tune frequency. Using this technique, tune shifts were measured and corrected successfully on the fast energy ramp. Measurement and correction of coherent synchrotron oscillations are feasible as well, utilizing a quite similar technique. Coherent synchrotron oscillations are excited by a phase jump of the acceleration voltage using an electrical phase shifter in the reference RF signal path.
KEK, Ibaraki
Crab cavities were installed in the KEKB rings in order to increase the luminosity. We measured the tilt of the bunches in the x-z plane using streak cameras. In a previous report*, the measured tilt in the HER was 2 times smaller than the expected crabbing angle, while the LER measurement was consistent with that expected. After the streak camera's vertical sweep speed was calibrated, the results were consistent with the expected crabbing angle in both rings.
* H. Ikeda et al., PAC07, 4018.
KEK, Ibaraki
Some of the improvement were done for an SR interferometer with the Herschelian reflective optics*. Previously, the measured vertical beam size was limited to around 5μm with a double slit separation of 40mm and wavelength of 400nm at the ATF damping ring. Double slit separation was mainly limited to the effective aperture of the optical path between the source point and interferometer. This time, we re-aligned the optical path, and as a result, the effective aperture was increased. Using this re-alignment we can have a double slit separation of up to 60mm. To reduce air turbulence, the optical path was covered with a tight air duct. After these improvements were made, we succeeded in measuring a vertical beam size of 3.4μm with double slit separation of 60mm and wavelength of 550nm, which corresponds to 5pm of the vertical emittance assuming 3m of the beta function.
* T. Naito et. al. "Very Small Beam Size Measurement by Reflective SR Interferometer at KEK-ATF", Proc. of EPAC06, pp2772-2274.
KEK, Ibaraki
MELCO SC, Tsukuba
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken
J-PARC, KEK & JAEA, Ibaraki-ken
To maintain the beam orbit of beam transport line from RCS to MR in J-PARC (3-50BT), 14 beam position monitors (BPMs) were installed. Their signals gathered in the local control building (D01) have been measured by using 14 digitizing oscilloscopes. The data acquisition system have a performance of shot-by-shot measurement.
KEK, Ibaraki
Osaka University, Osaka
Proton beam extinction, defined as a residual to primary ratio of beam intensity, is one of the most important parameters to realize the future muon electron conversion experiment (COMET) proposed at J-PARC. To achieve the required extinction level of 10-9, we started measuring beam extinction at main ring (MR) as the first step. The newly developed beam monitor was installed into the abort beam line and the first measurement was successfully performed by using the fast-extracted MR beam. We found that empty RF buckets of RCS, in which all protons were considered to be swept away by a RF chopper before injection to RCS,, contained about 10-5 of the main beam pulse due to chopper inefficiency. We are now developing a new beam monitor with improved performance for further studies at the abort line. In addition, we have started new measurements at the different stage of proton acceleration, i.e. at Linac, 3-50 BT line, and the main ring. In this paper, we present recent results and future prospect of beam extinction measurements.
Nagoya University, Nagoya
UVSOR, Okazaki
Sokendai - Okazaki, Okazaki, Aichi
Central Japan Synchrotron Radiation Research Facility which provides synchrotron radiation for a large community of users is under construction in the Aichi prefecture, Japan. The light source accelerator complex consists of a linac, a booster synchrotron and a storage ring. We have developed beam monitor systems which play important role especially in the commissioning stage of the accelerators. An RF knockout system to observe betatron tune of the electron beam in the booster synchrotron and the storage ring has been designed. We paid special attention in an RF source fed to a shaker to realize efficient measurement of the tune of electron beam during acceleration. We made a test experiment using electron beam of a booster synchrotron of the UVSOR facility. We have also developed a BPM system which enables a single path beam monitoring. The signal processing is based on a fast digital oscilloscope and a simple preprocessor circuit which was developed to improve position resolution. The performance was evaluated using an injection beam pulse to the storage ring of the UVSOR.
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken
KEK, Ibaraki
J-PARC, KEK & JAEA, Ibaraki-ken
The J-PARC RCS is an M-Watt class rapid cycling synchrotron and it has delivered an intensive beam to the neutron target and the MR. In order to overcome large space charge effect, its physical aperture is designed to be more than 250mm in diameter. Even though its chamber size is very large, the BPM system gives precise data to determine beam optics parameters of the ring. For this purpose, only relative positions and resolutions are important. However, for much higher intensity, the absolute beam position and accurate COD correction are indispensable. We have carefully installed the BPM and measured the position with respect to the quadrupole magnet (QM) nearby. But it is also necessary to estimate its absolute position by using beam. If each QM could be controlled independently, the simple beam based alignment technique can be utilized, but it is not the case for RCS. There are seven families of QM, and only each family can be controlled at one time. We developed a new technique by expanding the simple method for the case of multiple QM focusing changed simultaneously, and applied to the J-PARC RCS. The paper describes this method and discussed about experimental results.
USTC/NSRL, Hefei, Anhui
GigE Vision (Gigabit Ethernet vision standard) is a new interface standard for the latest vision of cameras with higher performance compared to analogue vision standard and other digital vision standard. In recent years, the market of industrial vision components is evolving towards GigE Vision. This paper presents applications of digital camera comply with GigE Vision standard for the measurement of beam profile and emittance at the storage ring of HLS (Hefei Light Source). These cameras provide low distortion for image transmission over long distance with high image rate. Using the image of beam profile transmitted by GigE Vision digital camera, we calculated the horizontal and vertical center positions, and then we calibrated these center positions by BPM (Beam Position Monitor) system. According to the result of calibration and the pixel size of CCD sensor, transverse sizes of beam profile were calculated, further more the transverse emittance and coupling factor were calculated as well.
KNU, Deagu
Kyungpook National University, Daegu
PAL, Pohang, Kyungbuk
The synchrotron-radiation interferometer was employed for the beam size measurement of electron beam circulating in the storage ring at 2.5 GeV Pohang Light Source. We measured the beam sizes in both vertical and horizontal directions as function of stored beam current. In this presentation, we will discuss the interferometer system, analysis method for the measurement and the measured results. We also compared the measured beam sizes with predicted values from the lattice parameters in the ring.
I-Tech, Solkan
PSI, Villigen
Measurements were performed at the Swiss Light Source on the beamline X06SA using a four-quadrant CVD diamond sensor which was connected to Libera Photon, a new photon BPM device from Instrumentation Technologies. The outputs of the sensor are 4 current signals in the nA range and are directly connected to the measuring unit without any pre-amplifiers. External bias voltage was applied, although the Libera Photon can supply internal bias voltage. Measurements consisted of: scanning the measurement range, frequency analysis of the beam movement and analysis of the photon beam flux influence on the measured position. The Sensor was mounted on a motorized XY stepper motor stage. Acquired data consisted of raw signal amplitudes and processed positions. Acquisitions were taken at 10 kHz and 10 Hz rate.
CERN, Geneva
SLAC, Menlo Park, California
The University of Liverpool, Liverpool
Synchrotron radiation is currently used on LHC for beam imaging and for monitoring the proton population in the 3 microsecond abort gap. In addition to these existing detectors, a study has been initiated to provide longitudinal density profiles of the LHC beams with a high dynamic range and a 50ps time resolution. This would allow for the precise measurement both of the bunch shape and the number of particles in the bunch tail or drifting into ghost bunches. A solution is proposed based on counting synchrotron light photons with two fast avalanche photo‐diodes (APD) operated in Geiger mode. One is free‐running but heavily attenuated and can be used to measure the core of the bunch. The other is much more sensitive, for the measurement of the bunch tails, but must be gated off during the passage of the core of the bunch to prevent the detector from saturating. An algorithm is then applied to combine the two measurements and correct for the detector dead time, after pulsing and pile‐up effects. Initial results from laboratory testing of this system are described in this paper.
CERN, Geneva
SLAC, Menlo Park, California
On the Large Hadron Collider (LHC), the continuous monitoring of the transverse sizes of the beams relies on the use of synchrotron radiation and intensified video cameras. Depending on the beam energy different synchrotron light sources must be used. A dedicated superconducting undulator has been built for low beam energies (450 GeV to 3 TeV), while edge and centre radiation from a beam separation dipole magnet are used respectively for intermediate and high energies (up to 7 TeV). The emitted visible photons are collected using a retractable mirror, which sends the light into an optical system adapted for acquisition using intensified CCD cameras. This paper presents the performance of the imaging system in terms of spatial resolution, and comments on the light intensity obtained and the cross calibration performed with the wire scanners. Upgrades and future plans are also discussed.
Diamond, Oxfordshire
JAI, Oxford
Electron bunch profile and length measurement from large bandwidth synchrotron radiation with a streak camera can be strongly limited by the chirp introduced by the length of material present in the input refractive optics of streak cameras. Elimination of the chirp can be done either by filtering the bandwidth of the synchrotron radiation pulses, by measuring time resolved spectra with the streak camera, or by replacing the front optics lenses by focussing mirrors. The first solution reduces the power available, thus limiting measurements to minimum bunch current that can be too high to assess the 'zero' current bunch length. The second elegant solution allows measurement of the bunch length with the whole bandwidth and available power but with loss of the second sweep axis in the camera, so that no beam dynamics can be observed. In order to prevent any pulse chirp, keep all the available power and capability of beam dynamics observation, we designed a new input optics exclusively with mirrors. We present here our design and the results of the system with our streak camera, measuring 2ps bunch in the new Diamond low-alpha lattice.
CLASSE, Ithaca, New York
KEK, Ibaraki
We report on the design and operation of the CesrTA x-ray beam size monitor (xBSM). The xBSM resolution must be sufficient to measure vertical beam sizes of order 10um by imaging 2-4keV synchrotron radiation photons onto a one-dimensional photodiode array. Instrumentation in the evacuated x-ray beam line includes upstream interchangeable optics elements (slits, coded apertures, and Fresnel zone plates), a monochromator and an InGaAs photodiode detector. The readout is a beam-synchronized FADC that is capable of parallel measurement of consecutive bunches with 4ns spacing. The xBSM has been used to measure beam sizes during the August 2009, November 2009, and April 2010 runs. Single turn measurements are fit to characteristic image shapes to extract beam sizes independent of position variations. The turn-averaged beam size provides feedback for low-emittance tuning.
RadiaBeam, Marina del Rey
Spectrum Detector, Lake Oswego, Oregon
UGA, Athens, Georgia
PSI, Villigen
This paper reports on the progress of the development of a bunch length diagnostic for high brightness beams. The diagnostic, termed the real time interferometer, is a single shot, autocorrelator that outputs the interferogram of coherent radiation emitted from compressed, high-brightness beams. The device uses all-reflective terahertz optics as well as a highly sensitive pyroelectric-based detector array. For initial testing, coherent transition radiation is used, however, the diagnostic can be used in a non-destructive manner if coherent edge or synchrotron radiation is employed. Current research includes diagnostic design and preliminary tests conducted at the BNL Accelerator Test Facility.
USC, Los Angeles, California
SLAC, Menlo Park, California
SPEAR3 is a third-generation synchrotron light source storage ring. The beam stability requirements are ~10% of the beam size, which is about 1 micron in the vertical plane. Hydrostatic level system (HLS) measurements show that the height of the SPEAR3 tunnel floor varies by tens of microns daily. We present analysis of the HLS data, including accounting for common-mode tidal motion. We discuss the results of experiments done to determine the primary driving source of ground motion. We painted the accelerator tunnel walls white; we temporarily installed Mylar over the asphalt in the center of the accelerator; and we put Mylar over a section of the tunnel walls.
GSI, Darmstadt
Non-destructive profile measurements are preferred not only for single-pulse diagnostics at different locations in a transfer line, but also to enable time resolved observations of stored the beam within a synchrotron. Moreover, the large beam power available at modern hadron accelerators excludes intersecting materials like screens, SEM-grids or scanners. Over the last years advanced concepts were realized: Ionization profile monitors are based on residual gas ionization and their spatially resolved detection. A complimentary method uses single photons detection of beam induced residual gas excitation. A third method is based on the deflection of a crossing electron beam to reconstruct the beam's transverse distribution. At LINACs for negative hydrogen acceleration, a scanning laser beam combined with a photo-electron detector was developed. The transverse profile can be monitored by means of a dedicated pick-up for the determination of the beam's quadrupole moment, i.e. the difference of the horizontal and vertical beam variance. The physical principles and technical realizations of these monitors are discussed.
DESY, Hamburg
PETRA III is a new hard x-ray synchrotron radiation source at DESY in Hamburg operating at 6 GeV with an extremely low horizontal emittance of 1 nmrad. The new light source is the result of a conversion of the former storage ring PETRA II. The conversion was carried out from middle of 2007 till March 2009. One eighth of the 2304 m long storage ring was completely rebuild and houses now 14 undulator beam lines as well as the optical and experimental hutches. The remaining seven eighths have been modernized and refurbished and in addition twenty 4 m long damping wigglers have been installed. These are required to achieve the small design emittance. Commissioning of the new light source started at the end of March 2009. In this paper we present the results that have been achieved during commissioning and the experience gained during the first user runs.
NIRS, Chiba-shi
AEC, Chiba
Based on more than ten years of experience of the carbon cancer therapy with HIMAC, we have proposed a new treatment facility for the further development of the therapy with HIMAC. This facility will consist of three treatment rooms: two rooms equipped with horizontal and vertical beam-delivery systems and one room with a rotating gantry. For the beam-delivery system of the new treatment facility, a 3D hybrid raster-scanning method with gated irradiation with patient's respiration has been proposed. A R&D study has been carried out toward the practical use of the proposed method. In the R&D study, we have improved the beam control of the size, the position and the time structure for the proposed scanning method with the irradiation gated with patient's respiration. Further, owing to the intensity upgrade of the HIMAC synchrotron, we can successfully extend the flattop duration, which can complete one fractional irradiation with one operation period. The building construction of the new treatment facility will be completed at March 2010 and treatment of 1st patient is scheduled at March 2011. We will report the recent progress on the new treatment facility project at HIMAC.
GSI, Darmstadt
IPCP, Chernogolovka, Moscow region
Universidad de Castilla-La Mancha, Ciudad Real
CERN, Geneva
Safety of the personnel and the equipment is an issue of great concern when operating with mighty particle beams like the ones generated by the LHC. Any uncontrolled release of even a very small fraction of the beam energy could cause considerable damage to the equipment. A worst case scenario is in which the entire beam is lost at a single point. Over the past years, we have carried out extensive numerical simulations to assess the consequences of an accident of this magnitude. We have simulated the thermodynamic and the hydrodynamic response of cylindrical targets made of solid copper and solid graphite, respectively, that are facially irradiated with one LHC beam. Our simulations show that the 7 TeV/c LHC protons will penetrate up to about 35 m in solid copper and about 10 m in solid graphite during the 89 μs beam duration time. In both cases, the target is severely damaged and a substantial part of the target is converted into High Energy Density Matter state.
NIRS, Chiba-shi
AEC, Chiba
Toshiba Medical Systems Corporation, Tochigi
In the routine operation of HIMAC synchrotron, a pulse system of field change with 0.2 Gauss in the monitor dipole magnet (B-clock) is used to generate pattern data in the acceleration system. To eliminate error pulse due to noise in analogue field signal, a clock system locked to a 1.2kHz clock for a power supplies was developed, which can be used to generate pattern data of an acceleration system with maximum frequency of 192kHz. This 1.2kHz clock is synchronized to a power line frequency of 50Hz that will fluctuate about 0.1%, so the clock of 192kHz must also follow this frequency fluctuation. To demonstrate the performance of new clock system, we have tested beam acceleration, and compared with the conventional B-clock system. Acceleration efficiencies were checked with changing these clock rates in the both systems. With these tests, we have found that the relatively low clock rate in the newly developed system is enough to get good acceleration performance. In this paper the clock system, and their beam tests will be presented.
SINAP, Shanghai
Currently, the real-time data transfer system is widely implemented in the accelerator control system. If timing system and real-time data transfer system could be combined into one uniform system, it would be convenient to build distributed feedback system, fast interlock system and so on. So, a new timing system, the real-time synchronized data bus is developed to realize this idea. The architecture of the system and the hardware prototype design are introduced in the paper. The data exchange mechanism and system specification, including timing trigger synchronization accuracy, timing jitter relative to RF clock, data transfer rate and latency are described in detail. Redundant topology structure and fiber length compensation are specially considered. In the end, the results of testing in lab are presented.
GSI, Darmstadt
The heavy ion synchrotron SIS18 at the GSI facility will be upgraded by a dual harmonic RF acceleration system in the process of using SIS18 as booster for the future FAIR SIS100 accelerator. The dual harmonic mode will extend the SIS18 operating towards higher beam currents. As a part of a large LLRF upgrade at the synchrotron RF systems at GSI, new FPGA and DSP based electronics have been designed, built and commissioned. To prove the functionality of the LLRF equipment as well as the general dual harmonic topology, machine development experiments using the existing cavities have been performed. During these experiments, the main parameters of the control loop were determined. Additionally, the impact of RF gap voltage amplitude and phase variations onto the ion beam have been investigated, like e.g. creation of a dual harmonic bucket or fast changes in harmonic number. The experiments showed a high sensitivity of the ion beam to small deviations in the phase between both harmonics and thereby confirmed the requirements on the high precision regarding phase accuracy of the electronic setup especially for the closed loop phase control systems.
SLAC, Menlo Park, California
CERN, Geneva
Radio Frequency (RF) accelerating system noise and non-idealities can have detrimental impact on the LHC performance through longitudinal motion and longitudinal emittance growth. A theoretical formalism has been developed to relate the beam and RF loop dynamics with the bunch length growth [1]. Measurements were conducted at LHC to validate the formalism, determine the performance limiting RF components, and provide the foundation for beam diffusion estimates for higher energies and intensities. A brief summary of these results is presented in this work.
[1] T. Mastorides et. al., "RF system models for the LHC with Application to
Longitudinal Dynamics", prepared for submission to Physical Review ST-AB.
NSRRC, Hsinchu
The Taiwan Photon Source (TPS) is a third generation synchrotron accelerator which the designed energy will be 3 GeV whereas the current is 500mA. The role of crotch absorber is designed to protect downstream UHV vacuum chamber. It is is the only mask component to absorb large amount of synchrotron radiation (bending magnet) in the storage ring. Crotch absorber is installed from transverse direction of the bending chamber to intercept the power. Two bent OFHC copper tubes are vacuum brazed on the copper mask. A 30 degree groove is machined to face bending magnet fan. The reason is not only to dissipate the heat but also to limit back scattering to the rest of chambers. Top and bottom of the absorber are bolted with beryllium copper springs; they will provide extra support for the absorber after it is installed in the Aluminum chamber. Three thermocouples will be embedded inside of the mask to monitor the temperature gradient. Final prototype of the crotch absorber with thermal analysis, design and machined parts are also presented in this paper.
CEA, Gif-sur-Yvette
LPSC, Grenoble Cedex
Lattice design tools are being developed, and related beam and spin dynamics simulations are being performed, in the framework of the international collaboration regarding the super-B project. The present contribution reports on this work.
CERN, Geneva
UMAN, Manchester
Cockcroft Institute, Warrington, Cheshire
The University of Liverpool, Liverpool
DESY, Hamburg
DESY Zeuthen, Zeuthen
INFN-Bologna, Bologna
The LHeC aims at colliding hadron-lepton beams with center of mass energies in the TeV scale. For this purpose the existing LHC storage ring is extended by a high energy electron accelerator in the energy range of 60 to 140 GeV. The electron beam will be accelerated and stored in a LEP like storage ring in the LHC tunnel. In this paper we present the layout of the interaction region which has to deliver at the same time well matched beam optics and an efficient separation of the electron and proton beams. In general the large momentum difference of the two colliding beams provides a very elegant way to solve this problem: A focusing scheme that leads to the required beam sizes of the electrons and protons is combined with an early but gentle beam separation to avoid parasitic beam encounters and still keep the synchrotron radiation level in the IR within reasonable limits. We present in this paper two versions of this concept: A high luminosity layout where the mini beta magnets are embedded into the detector design as well as an IR design that is optimised for maximum acceptance of the particle detector.
Ankara University, Faculty of Sciences, Tandogan/Ankara
CERN, Geneva
In a linac-ring electron-proton collider based on the LHC, before and after the collision point the electron beam can be deflected with weak dipole magnets positioned in front of the superconducting final quadrupole triplets of the 7-TeV proton beam. Significant synchrotron radiation may be produced when the electron beam, of energy 60-140 GeV, passes through these dipole magnets. As an alternative or complement to shielding, parts of the synchrotron radiation could be extracted together with the electron beam. We propose using mirrors with shallow grazing angle to deflect the synchrotron radiation away from the proton magnets. Various LHeC options are considered. Limitations and challenges of this approach are discussed.
BNL, Upton, Long Island, New York
IKP, Mainz
FZJ, Jülich
To facilitate studies of collisions between polarized electron and protons at √{s} = 14 GeV constructing an electron-nucleon collider at the FAIR facility has been proposed. This machine would collide the stored 15 GeV polarized proton beam in the HESR with a polarized 3.3 GeV electron beam circulating in an additional storage ring. We describe the interaction region design of this facility, which utilizes the PANDA detector.
BNL, Upton, Long Island, New York
A fast transition instability presents a limiting factor for ion beam intensity in RHIC. Several pieces of evidence show that electron clouds play an important role in establishing the threshold of this instability. In RHIC Runs 7 and 8 dedicated measurements of the instability, using different beam instrumentation tools (Button BPM, Wall Current Monitor, transition monitors) were done in order to observe the instability development over hundreds turns. The papers presents and discusses the results of those measurements in time and frequency domains.
BINP SB RAS, Novosibirsk
A new beam extraction scheme from a synchrotron is put forward. The main difference from other schemes of extraction is the use of a magnetic shields instead of a septum. Magnetic shields are located in the central dipole magnets of a pulsed chicane. The magnetic shield is a multi-layer copper-iron tube. Numerical simulations and experimental results for the magnetic shield are presented. A good accordance between them has shown. The advantages of the new scheme are easy technical implementation and compactness. The area of application is extraction from a synchrotron. The proposed scheme will be used in a new synchrotron radiation source in Novosibirsk.
ASCo, Clayton, Victoria
ELETTRA, Basovizza
Monash University, Faculty of Science, Victoria
We report the development of an artificial intelligent system for the optimisation of electron beam parameters at the Australian Synchrotron Linac. The system is based on state of the art developments in Artificial Intelligence techniques for video games and is adapted here to beam parameters optimisation problems. It consists of a genetically evolved neural network that mimics an operator's decisions to perform an optimisation task when no prior knowledge other than constraints on the actuators is available. The system's decisions are based on the actuators positions, the past performance of close points in the search space and the probability of reaching a better performance in the local region of the search space.
USTC/NSRL, Hefei, Anhui
In order to obtain more straight sections for insertion devices and higher brilliance synchrotron radiation, an upgrade project of Hefei Light source (HLS) is undergoing. A new injection system has been designed to improve injection efficiency and keep the machine running stably. Four kickers will be used to generate a local injection bump. Effects of injection system to injecting beam and stored beam have been simulated considering errors. Finally, ELEGANT code was used to simulate the injection process with new designed bump system. The simulation results show that the injection efficiency would be higher than 99% and perturbation on stored beam would be small enough, which are benefit to full energy injection and top-up operation of HLS in the future.
SLAC, Menlo Park, California
BNL, Upton, Long Island, New York
Life Imaging Technology, Palo Alto, California
As SPEAR3 moves closer to trickle-charge topup injection, the complex phase-space dynamics of the injected beam becomes increasingly important for capture efficiency and machine protection. In the horizontal plane the beam executes ~12mm betatron oscillations and begins to filament within 10's of turns. In the vertical plane the beam is more stable but a premium is placed on flat-orbit injection through the Lambertson septum and the correct optical match. Longitudinally, energy spread in the booster is converted to arrival-time dispersion by the strong R56 component in the transfer line. In this paper, we report on turn-by-turn imaging of the injected beam in both the transverse plane and in the longitudinal direction using a fast-gated ccd and streak camera, respectively.
Sokendai, Ibaraki
KEK, Ibaraki
Electron Cloud (ECLOUD) deteriorates the performance of proton and positron storage rings. Therefore it is desirable to understand the ECLOUD buildup in a given machine. The data taken by Retarded Field Analyzer (RFA) with a multi channel plate showed that the signal had the peaks coinciding with the positron bunch pattern if a high voltage of -2kV is applied to the retarded grid*. This suggests that the cloud electrons get maximum kick near the positron bunch. A computer program has been developed to study the near bunch ECLOUD density at KEKB LER (Low Energy Ring). In simulations, secondary electron emission is modeled according to the Furman and Pivi's model**. In this paper we compare the simulation results of the ECLOUD buildup with the experiments performed in KEK under different beam-optics elements.
* K. Kanazawa et al., PAC05, 1054.
** M. Furman and M. Pivi, PRST-AB, 5, 124404 (2002).
CASA, newport news
JLAB, Newport News, Virginia
We present early stage of a new code for self-consistent, 2D simulations of beam dynamics affected by CSR. The code is of the particle-in-cell variety: the beam bunch is sampled by macroparticles, which are deposited on the grid; the corresponding forces on the grid are then computed using retarded potentials according to causality, and interpolated so as to advance the particles in time. The retarded potentials are evaluated by integrating over the 2D path history of the bunch, with the charge and current density at the retarded time obtained from interpolation of the particle distributions recorded at discrete timesteps. The code is benchmarked against analytical results obtained for a rigid-line bunch. We also outline the features and applications which are currently being developed.
KIT, Karlsruhe
FZK, Karlsruhe
The ANKA light source is regularly operated with a low momentum compaction factor lattice where short bunches are created for the generation of coherent synchrotron radiation (CSR). Short bunches with high electron density can generate strong self fields which act back on the bunch. This can lead to bunch shape deformation and a microbunching instability which were studied theoretically for the ANKA low alpha parameters (Klein et al. PAC 09). We extended these studies to a comparison of calculated electron distributions and bunch profiles measured with a streak camera. The Haissinski equation was solved for the CSR impedance to obtain a prediction for the distortion of the bunches for different bunch lengths and bunch currents. The comparison shows that the theory predicts a much stronger deformation caused by CSR than the streak camera observes. However, high frequency components of measured FTIR spectra show a clear indication for strong deformation or small
LBNL, Berkeley, California
BNL, Upton, Long Island, New York
Fermilab, Batavia
CERN, Geneva
SLAC, Menlo Park, California
A new proton synchrotron, the PS2, is under design study to replace the the current proton synchrotron at CERN for the LHC upgrade. Nonlinear space charge effects could cause significant beam emittance growth and particle losses and limit the performance of the PS2. In this paper, we report on studies of the potential space-charge effects at the PS2 using three-dimensional self-consistent macroparticle tracking codes, IMPACT, MaryLie/IMPACT, and Synergia. We will present initial benchmark results among these codes. Effects of space-charge on the emittance growth, especially due to synchrotron coupling, and the aperture sizes will also be discussed.
ASCo, Clayton, Victoria
Melbourne
The Australian Synchrotron storage ring must maintain a stable electron beam for user operations. The impedance characteristics of the storage ring can give rise to instabilities that adversely affect the beam quality and need to be well understood. Collective effects driven by the resistive wall impedance are particularly relevant at the Australian synchrotron and their strengths are enhanced by small gap insertion devices, such as IVUs. This study will explore the impedance issues identified in the Australian Synchrotron storage ring and current mitigation techniques.
KEK, Ibaraki
The near beam electron cloud density in a magnetic field was estimated with a simple electron current detector at KEKB LER. The estimation is based on the assumption that high energy electrons which hit a chamber wall come directly from the region around the beam after the interaction with a circulating bunch. The first successful application of this idea for a drift space was reported at PAC05 by the authors. In a solenoid field of 50 G, the near beam cloud density is reduced by about four orders of magnitude compared to the no field case. In a quadruple magnet, the density around the beam is by two orders of magnitude lower than the density in a typical drift space, as most simulations show.
CERN, Geneva
The effects of direct space charge forces on the Transverse Mode Coupling Instability (TMCI) are studied using numerical techniques. We have implemented a third order symplectic integrator for the equation of motion, taking into account non linear space charge forces coming from a Gaussian shaped bunch. We performed numerical simulation for the Super Proton Synchrotron (SPS) bunch at 26 GeV of kinetic energy, using either resistive wall or broad band transverse wake fields. In both cases the result of applying direct space charge, leads to an intensity threshold increase by almost 20% before the TMCI appears. Far above the TMCI intensity threshold, the growth rate is almost 10% higher if no space charge forces are applied.
CERN, Geneva
Since many years the Proton Synchrotron Booster (PSB) high intensity beams have shown head-tail instabilities in all of the four rings at around 100 ms after the injection. In this paper we present the latest observations together with the evaluation of the instability rise time and its dependence on the bunch intensity. The acquired head-tail modes and the growth rates are compared with HEADTAIL numerical simulations, which together with the Sacherer theory points at the resistive wall impedance as a possible source of the instability.
CERN, Geneva
EPFL, Lausanne
The kickers are major contributors to the CERN SPS beam coupling impedance. As such, they may represent a limitation to increasing the SPS bunch current in the frame of an intensity upgrade of the LHC. In this paper, CST Particle Studio time domain electromagnetic simulations are performed to obtain the longitudinal and transverse impedances/wake potentials of simplified models of ferrite loaded kickers. The simulation results have been successfully compared with some existing analytical expressions. In the transverse plane, the dipolar and quadrupolar contributions to the wake potentials have been estimated from the results of these simulations. For some cases, simulations have also been benchmarked against measurements on PS kickers. It turns out that the large simulated quadrupolar contributions of these kickers could explain both the negative total (dipolar+quadrupolar) horizontal impedance observed in bench measurements and the positive horizontal tune shift measured with the SPS beam.
Fermilab, Batavia
We investigate the dynamics of longitudinally flat bunches created with a second harmonic cavity in a high energy collider. We study Landau damping in a second harmonic cavity with analytical and numerical methods. The latter include particle tracking and evolution of the phase space density. The results are interpreted in the context of possible application to the LHC.
SLAC, Menlo Park, California
In accelerator design, there is often a need to evaluate the threshold to the (longitudinal) microwave instability for a bunched beam in a storage ring. Several computational tools are available that allow us, once given a wakefield, to numerically find the threshold current and to simulate the development of the instability. In this work, we present the results of computer simulations with codes recently developed at the SLAC National Accelerator Laboratory. Our simulations include the cases of the resonator broadband impedance, the resistive wall impedance and the coherent synchrotron radiation impedance. We compare the accuracy of the threshold prediction and discuss the capabilities and limitations of the codes.
NSC/KIPT, Kharkov
KEK, Ibaraki
CERN, Geneva
Compton sources are capable to produce intense beams of gamma-rays necessary for numerous applications, e.g. production of polarized positrons for ILC/CLIC projects, nuclear waste monitoring. These sources need high current of electron beams of GeV energy. Storage rings are able to accumulate a high average current and keep it circulating for a long time. The dynamics of circulating bunches is affected by large recoils due to emission of energetic photons. We report results of both an analytical study and a simulation on the dynamics of electron bunches circulating in storage rings and interacting with the laser pulses. The steady-state transverse emittances and energy spread, and dependence of these parameters on the laser pulse power and dimensions at the collision point were derived analytically and simulated. It is shown that the transverse and longitudinal dimensions of bunches are dependent on the power of laser pulses and on their dimensions as well. Conditions of the laser cooling were found, under which the electron bunches shrink due to scattering off the laser pulses. The beam behavior in rings with the longitudinal strong focusing lattices is discussed.
SOLEIL, Gif-sur-Yvette
ANL, Argonne
SOLEIL is presently installing a laser bunch slicing set-up to produce ultra-short X-ray pulses. We propose a method to generate coherent synchrotron radiation at high harmonics in a storage ring using an echo scheme. Like in the method proposed recently for free electron lasers, the echo scheme uses two modulators and two dispersive sections. We show that this can be done at the synchrotron SOLEIL by adapting the classical slicing scheme. In the present study at SOLEIL, the two laser/electrons interactions are planned to occur in two out of vacuum wigglers of period 150 mm, and the high harmonic radiation will be emitted in an APPLE-II type undulator with a period of 44mm or 80 mm in the beamline TEMPO or with a period of 52 mm in the beamline DEIMOS.
CLASSE, Ithaca, New York
Coherent Synchrotron Radiation (CSR) can be a detrimental effect on particle bunches with high charge and short bunch lengths. CSR can contribute to an increase in emittance and energy spread, and can limit the process of bunch compression. It is especially important in Energy Recovery Linacs (ERLs), because any relative energy spread induced at high energy is magnified after deceleration, and any energy lost by the particles is energy that cannot be recovered. Here we present CSR simulation results using the particle tracking code BMAD for the main operation modes in the proposed Cornell ERL, including an additional bunch compression mode. These simulations consider the effect of CSR shielding, as well as CSR propagation between bends.
Stanford University, Stanford, California
SLAC, Menlo Park, California
By operating SPEAR3 in the quasi-isochronous (low-alpha) mode, one can produce synchrotron radiation with pulse durations of order 1ps. Applications include pump-probe x-ray science and the production of THz radiation. Measurements of short pulse lengths are difficult, however, because the light intensity is low and streak camera resolution is of order 2ps. Bunch arrival time and timing jitter are also important factors. In order to further quantify the pulse length and timing system performance, a 5MHz, 50fs mode-locked laser was used to cross-correlate with the visible SR beam in a BBO crystal. The 800nm laser pulse was delayed with a precision mechanical stage and the product SHG radiation detected with a photodiode / lock-in amplifier using the ring frequency as reference. In this paper we report on the experimental setup, preliminary pulse length measurements and prospects for further improvement.
KEK, Ibaraki
Japan has a long history of academia-industry collaboration on accelerator technology development. A recent example is superconducting cavity manufacture for the linear collider as well as a number of collaboration in superconducting magnets for circular colliders and physics experiments. Experience with Academia-industry Collaboration on Accelerator Projects in Japan and global Asia will be presented.
TUB, Beijing
Different kinds of accelerators, such as electron linacs, cyclotrons, microtrons, HV DC accelerators, synchrotrons and betatrons, can be used in radiotherapy, Non-Destructive Test, and irradiations. The accelerator industry in Asia almost covers all of the accelerators and application areas above. In this paper, the status and the trend of the accelerator industry in Asia will be introduced. Typical examples, in the areas of medial and industrial applications, will be described about their technology, achievement and relationship with universities or institutes. For the accelerator technology is strongly relied on the development of components, we will also briefly introduce the industry in Asia of some components, such as rf power sources, HV power sources (modulator), magnets and so on.
CELLS-ALBA Synchrotron, Cerdanyola del Vallès
European industry has participated in the LHC Project for technology development, component design and system construction. A good relationship in academia-industry collaboration has led to successful results for the project. Industry plays an important role for component design, manufacture and system construction in the XFEL project. The long history of academia-industry collaboration in the accelerator field in Europe is presented.
I-Tech, Solkan
After LHC completion, maintenance and operation of the facility provide a good opportunity for accelerator industry in Europe. Other big facilities like XFEL, FAIR, FERMI@ELETTRA and MAX IV are now under way. The challenges of the accelerator industry in Europe and its future outlook will be presented.
ASCo, Clayton, Victoria
The Australian Synchrotron has been running normal operations for beamlines since April 2007. The high degree of beam availability has allowed for an extensive accelerator physics program to be developed. The main points of this program will be presented, including student involvement at different levels and developments being made in anticipation of moving to top-up mode injections.
ASCo, Clayton, Victoria
The Australian Synchrotron has been open to users since April 2007. Beam availability is now consistently above 98%, with a Mean Time Between Failures (MTBF) of approximately 50 hours and a Mean Down Time (MDT) of approximately 1 hour. This paper discusses the program of activities that has been undertaken to improve beam availability, and to maximize the MTBF and reduce the MDT.
Monash University, Faculty of Science, Victoria
ASCo, Clayton, Victoria
The Australian Synchrotron booster synchrotron accelerates electrons from 100 MeV to 3 GeV in 600 ms. The fractional tune components that were measured are presented in two graphical formats showing the time-resolved measurement of the horizontal and vertical tunes. This experiment demonstrated that the current in the booster was extremely sensitive to the ratio of BF to BD combined-function magnets. Large variations of the fractional tunes were found to follow the differences in the gradients of the BD and BF combined-function magnet ramping curves and with this knowledge, alterations were made to the ramping table increasing the efficiency of the booster by on average 40%. Rapid fluctuation of the tunes meant that it could not be distinguished during the first 80ms of the ramp. Multiple side bands to the revolution harmonic were visible during a minimal sweep time of 2.5ms, during this first 80ms.
LNLS, Campinas
Karlsruhe Institute of Technology (KIT), Karlsruhe
In the beginning of 2008 an upgrade of the beam position monitors (BPMs) of the Brazilian Synchrotron Light Source (LNLS) electron storage ring was decided and scheduled as part of the continuous effort to improve the electron beam orbit stability. The objective was to replace most of the 24 BPMs installed in the storage ring and install new radiation absorbers inside the vacuum chamber. The original stripline BPMs were sensitive to temperature changes in the vacuum chamber. Heat, which induced mechanical stress in the striplines, could lead to fluctuations in the position readings thereby disturbing the orbit stability. The problem affected differently the BPMs. Although not a great issue during a typical user shift, the perturbations could pose some problems for the most sensitive experiments. One third of the BPMs were replaced in October 2008 and the remaining in October 2009. Thus, this large vacuum intervention aimed at improving the thermal and mechanical stability of the electron beam orbit measurement system. Finally, it will be presented the main changes made in the vacuum chambers and a survey of the evolution of the vacuum system after both interventions.
LNLS, Campinas
We report on the status of SIRIUS (BR), the new 3 GeV synchrotron light source currently being designed at the Brazilian Synchrotron Light Laboratory (LNLS) in Campinas, Brazil. The new light source will consist of a low emittance storage ring based on the use of permanent magnet technology for the dipoles. An innovative approach is adopted to enhance the performance of the storage ring dipoles by combining low field (0.5 T) magnets for the main beam deflection and a short slice of high field magnet. This short slice will create a high bending field (2.0 T) only over a short longitudinal extent, generating high critical photon energy with modest energy loss from the complete dipole. There are several attractive features in this proposal, including necessity for lower RF power, less heating of the vacuum chambers and possibility to reduce the beam emittance by placing the longitudinal field gradient at a favorable place.
CLS, Saskatoon, Saskatchewan
Preliminary observations of coherent synchrotron radiation (CSR) at the Canadian Light Source have been reported earlier. At that time a more suitable operating point was identified based on particle tracking calculations. These calculations showed that a large stable longitudinal phase space can be achieved through adjustment of the chromaticities. With the implementation of these operating conditions CSR has been produced with much improved beam lifetime. CSR has been produced both with multiple bunches at 1.5 GeV and with a single bunch at the nominal 2.9 GeV beam energy. The production of CSR with these new operating points has proven to be reliable and repeatable. Operations at the nominal beam energy allows for setup times of under 20 minutes. With a beam lifetime (1/e) of over 7 hours single shifts dedicated to CSR production are now practical.
Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Berlin
Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Elektronen-Speicherring BESSY II, Berlin
In this paper we present the results of our studies employing LOCO and MML for optics calibration at the MLS and at the BESSY II storage rings. Both the standard user modes and dedicated low alpha modes were analysed.
DESY, Hamburg
At DESY the PETRA ring has been converted into a synchrotron radiation facility, called PETRA III. The commissioning with beam started in April 2009. The betatron tune versus beam intensity was measured for different configurations of the wiggler magnets which are installed in PETRA III to achieve the small emittance of 1 nm. These measurements are compared with predictions from the impedance model. The measured tune shift is well within the impedance budget and the design single bunch intensities of up-to 2.5 mA can be stored in PETRA III. The predicted vertical tune shift is about 30 % smaller than the measured one.
KIT, Karlsruhe
A dedicated optics with a low momentum compaction factor is used at the ANKA storage ring to reduce the bunch length to generate coherent synchrotron radiation (CSR). A double sweep streak camera is employed to determine the bunch length and shape for different optics and as a function of the beam current. Measurements of the longitudinal bunch profile have been performed for many different momentum compaction factors and various bunch currents. This paper describes the set up of the streak camera experiments and compares the measured bunch lengths to theoretical expectations.
KIT, Karlsruhe
Technische Universität Berlin, Berlin
DLR, Berlin
Since a few years CSR-Radiation created in low alpha mode is provided by the ANKA light source of the KIT*. Depending on the bunch current, the radiation is emitted in bursts of high intensity. These bursts display a time evolution which can be observed only on long time scales with respect to the revolution period. The intensity of the emitted radiation during a burst is significantly increased w.r.t. steady state emission. Some users of the THz radiation don't require particularly constant emission characteristics and could profit from the higher intensity. A better understanding of the long term behaviour of those bursts could help to improve the conditions for those users. We have investigated THz radiation in multiturn mode with a hot electron bolometer. Its time response of 165ps allowed us to resolve the signals of individual bunches. Using a 6GHz LeCroy oscilloscope for data acquisition, we were able to save up to 1.6ms long signal sequences at a sampling rate of 20GS/s. This amount of data corresponds to over 4000 bunch revolutions and allows turn-by-turn signal tracking of desired bunches. In single bunch mode we are able to take segmented data to avoid a huge overhead.
* KIT - Karlsruhe Institute for Technology
KIT, Karlsruhe
Technische Universität Berlin, Berlin
DLR, Berlin
In synchrotron radiation sources coherent radiation is emitted when the bunch length is comparable to or shorter than the wavelength of the emitted radiation. At the ANKA storage ring this radiation is observed as so-called edge radiation (emitted in the fringe field of a bending magnet). This radiation exhibits a radial polarisation pattern. The observed pattern, however, is influenced by the radiation transport in the beam line. A detector system based on a superconducting NbN ultra-fast bolometer with an intrinsic response time of about 100 ps as well as conventional Si bolometers were used to study the beam polarisaion. This paper reports the observations made during measurements.
IPM, Tehran
An overview of the 3 GeV Synchrotron radiation source, which is under design in Iran will be presented with emphasis on site location studies, user demands and general parameters of the machine. The background to the proposed facility and different aspects of the machine design also is reported. Operating this third generation light source with 3 GeV storage ring and beam currents of up to 400mA, will result in a source of very intense light over a broad range of photon energies from the IR to hard X-rays to a community that is expected to exceed 500 users a few years after the start of operation in 2015 .
NewSUBARU/SPring-8, Laboratory of Advanced Science and Technology for Industry (LASTI), Hyogo
JASRI/SPring-8, Hyogo-ken
The periodic fluctuations and drifts in the radiation intensity have been observed at the NewSUBARU synchrotron radiation facility. To clarify the cause of this problem we have measured temperatures of air, cooling water, equipments and building with the network-distributed data logger. And we found that temperature fluctuations in both air in the shielded tunnel and the cooling water mainly affect the stabilities of electron beam orbit and optical axis. To maintain a constant temperature, the large doors for carrying equipment at the experimental hall were covered with insulated curtains, and we optimized PID parameters of temperature controllers for air and water. As results, the periodic fluctuations almost disappeared, but some drifts were still remained, which are due to slow variations of equipment temperature. By realizing the automatic COD correction, the drift in electron beam position could be suppressed and the fluctuations of radiation intensity observed at beam-lines became smaller than they used to be. For further stabilization, we recently introduced a XBPM upstream in a beamline to measure the vertical position of radiation axis precisely.
Nagoya University, Nagoya
KEK, Ibaraki
UVSOR, Okazaki
SAGA, Tosu
JASRI/SPring-8, Hyogo-ken
Central Japan Synchrotron Radiation (SR) Research Facility is under construction in the Aichi area, and the service will start from FY2012. Aichi Science & Technology Foundation is responsible for the operation and management, and Nagoya University SR Research Center is responsible to run the facility and support the users technically and scientifically. The accelerators consists of an injector linac, a booster synchrotron and an 1.2 GeV electron storage ring with the circumference of 72 m. To save construction expenses, the 50 MeV linac and the booster with the circumference of 48 m are built at inside of the storage ring. The beam current and natural emittance of the storage ring are 300 mA and 53 nmrad. The magnetic lattice consists of four triple bend cells and four straight sections 4 m long. The bending magnets at the centers of the cells are 5 T superbends and the critical energy of the SR is 4.8 keV. More than ten hard X-ray beam-line can be constructed. One variable polarization undulator will be installed in the first phase. The electron beam will be injected from the booster with the full energy and the top-up operation will be introduced as early as possible.
UVSOR, Okazaki
Sokendai - Okazaki, Okazaki, Aichi
Nagoya University, Nagoya
UVSOR-II is a low emittance, 750 MeV synchrotron light source. Low emittance and low energy synchrotron light sources naturally suffered from short electron lifetime due to Touschek effect. Top-up operation is a solution for overcoming the effect. In the UVSOR-II, trials of multi-bunch top-up operation at the full energy were started from 2008. In the trials, we have succeeded in keeping the stored beam current around 300 mA for 12 hours. From this fiscal year, single bunch injection was started for single bunch user operations and for experiments on advanced light source development such as Free Electron Laser (FEL), Coherent Synchrotron Radiation (CSR), Coherent Harmonic Generation (CHG), which require single bunch or 2-bunch filling operation. We have already performed single bunch top-up operation in user time with the stored beam current of 50 mA. And FEL lasing with top-up operation was also achieved at the laser wavelength of 215 nm with the stored beam current of 130 mA / 2-bunch. In the FEL lasing experiment, we succeeded in keeping the average power of FEL around 130 mW for three hours.
USTC/NSRL, Hefei, Anhui
HLS (Hefei Light Source) is a dedicated synchrotron radiation research facility, whose emittance is relatively large. In order to improve performance of the machine, especially getting higher brilliance synchrotron radiation and increasing the number of straight sections for insertion devices, an upgrade project is on going. A new low emittance lattice, which keeps the circumference of the ring no changing, has been studied and presented in this paper. For the upgrade project, a new ring will be installed on current ground settlement of HLS and all of the magnets will be reconstructed. After optimization, two operation modes have been chosen for different users. Nonlinear dynamics shows that dynamic aperture for on-momentum and off-momentum particle is large enough. Beam lifetime has also been studied. Calculation results proves that expected beam lifetime about 8.5 hours can be obtained with a fourth harmonic cavity operation.
CELLS-ALBA Synchrotron, Cerdanyola del Vallès
The Synchrotron Light source ALBA is entering the commissioning period and beam should be provided to the users by the end of 2010. The installation of the full energy 3 GeV booster is finished, with the commissioning taking place in January 2010. The installation of the storage ring is almost finished and the commissioning should take place in summer 2010. The detailed milestones of the project are presented.
BNL, Upton, Long Island, New York
The booster synchrotron for NSLS-II accepts beam with 200 MeV from a linac and raises its energy up to 3 GeV. In order to raise beam energy up to 3 GeV, a 7-cell PETRA cavity is installed. Beam instabilities related with the cavity are discussed. In particular, in order to avoid coupled-bunch instability, we consider that cooling water temperature for the cavity should be changed to shift frequencies of higher order modes (HOM) to avoid beam revolution lines. To obtain the relation between the temperature dependence of amount of frequency shift in each HOM and cavity body temperature, we carried out the measurement by changing cavity body temperature. From the measurement data, we calculate the required temperature variation. We summarize the results and describe the system design.
KEK, Ibaraki
Kanto Information Service (KIS), Accelerator Group, Ibaraki
ACMOS INC., Tokai-mura, Ibaraki
J-PARC, KEK & JAEA, Ibaraki-ken
The beam commissioning of the J-PARC Main Ring started in May, 2008. Data archive system has been developed using Channel Archiver, which is a tool developed and maintained in the EPICS community. Various machine parameters and status information of Main Ring have been recorded. The number of records registered extends 17,000 as of December, 2009. The archive data can be retrieved in a form of graphical representation by Web browser. In addition, the mechanism to provide bit-type information, such as interlock and on/off, in time series format is available. They have been used in daily operation of Main Ring. Addition to them, we are trying to develop a new scheme to record large waveform data of beam diagnostic signals. Status and progress of the archive system will be discussed.
NSRRC, Hsinchu
To enhance waveform and spectrum remote access supports in the Taiwan Light Source (TLS), development of the EPICS support of Ethernet-based oscilloscope and spectrum analyzer for the TLS is under way. The EPICS platforms which built to interface these instruments could access the waveform and spectrum through the PV (Process Variable) channel access. By using remote operations of waveform and spectrum acquisition, long distance cabling could be eliminated and signal quality be improved. The EDM (Extensible Display Manager) tool is used to implement the operation interface of control console and provide waveform display. According to specific purpose use, different graphical user interfaces to integrate waveform and spectrum acquisition are built. This project is the preparation for future control room integration with the Taiwan Photon Source control room. The efforts will be described at this report.
NSRRC, Hsinchu
Implementation of the Control system for the Taiwan Photon Source (TPS) is on going. The TPS control system will provide versatile environments for machine commissioning, operation, and to do accelerator experiments. The control system is based on EPICS toolkits. Test-bed has set up for various developments. The open architecture will facilitate machine upgrade, modification easily and minimize efforts for machine maintenance. Performance and reliability of the control system will be guaranteed from the design phase. Development status will be summary in this report.
Melbourne
ASCo, Clayton, Victoria
The Australian Synchrotron storage ring has a resistive wall instability in the vertical plane. Presently this instability is being controlled by increasing the vertical chromaticity. However new in-vacuum insertion devices that significantly increase the ring impedance may demand chromatic corrections beyond the capabilities of the sextupole magnets. A transverse bunch-by-bunch feedback system has been commissioned to combat the vertical instability* and provide beam diagnostics**. A high frequency narrow band mode that could not be damped was initial encountered with IVUs at minimum gap preventing the system from being implemented during user beam. Tuning of the bunch fill pattern, the digital filters and mapping out the system response lead to a configuration for user mode operations.
* Spencer, M.J. et. al. EPAC'08, Genoa, Italy
** Peake, D.J. et. al. PAC'09, Vancouver, Cananda
DELTA, Dortmund
Dimtel, San Jose
DELTA is a 1.5-GeV synchrotron radiation source at the TU Dortmund University with 2 ns bunch spacing. At nominal operating currents, the beam exhibits significant longitudinal centroid motion due to coupled-bunch instabilities. Two techniques were successfully used at DELTA to damp such instabilities: RF phase modulation, which also improves the beam lifetime, and bunch-by-bunch feedback. Using diagnostic data from the bunch-by-bunch feedback system, modal spectra and growth rates of the longitudinal instabilities were characterized. We also present a preliminary characterization of transverse coupled-bunch oscillations observed at the highest beam currents.
JASRI/SPring-8, Hyogo-ken
Electricity generation from scattered secondary particles has been examined for a kind of energy-recovery by using a beam loss monitor at the SPring-8 storage ring, in which PIN photodiodes are utilized without a reversed bias voltage in similar to a solar cell. The system and results will be reported.
CERN, Geneva
SLAC, Menlo Park, California
The LHC beam dump system relies on extraction kickers that need 3 microseconds to rise up to their nominal field. As a consequence, particles crossing the kickers during this rise time will not be dumped properly. The proton population during this time should remain below quench and damage limits at all times. A specific monitor has been designed to measure the particle population in this gap. It is based on the detection of Synchrotron radiation using a gated photomultiplier. Since the quench and damage limits change with the beam energy, the acceptable population in the abort gap and the settings of the monitor must be adapted accordingly. This paper presents the design of the monitor, the calibration procedure and the detector performance with beam.
INFN/LNF, Frascati (Roma)
CNAO Foundation, Milan
CNAO, the Italian Centre of Oncological Hadrontherapy located in Pavia, is under commissioning and will be soon fully operational. It is based on a synchrotron that can accelerate carbon ions up to 400 MeV/u and protons up to 250 MeV for the treatment of patients. In this paper we present the subsystem, called B-Train, which has the purpose of measuring the magnetic field in a dedicated dipole connected in series with the sixteen dipoles of the synchrotron and to provide instantaneous values of the synchrotron field to the dipole power supply, to the RF, diagnostics and dump bumpers control systems, via optical lines, using a custom communication protocol. In order to measure the magnetic field with the specified precision (0.1G over 1.5T @ 3 T/s), a different approach has been taken with respect to previous versions of the system. The field is obtained by digitizing the voltage induced on a pick-up coil inserted in the gap of the dedicated dipole through a 18 bit, 1.25 Msamples/s ADC and integrating it by numerical methods. This paper describes the final design and features of the B-Train system, as well as the results obtained on the magnetic field readings precision.
DESY, Hamburg
The prototype of a camera system developed at KEK/Kyoto University for the optical inspection of the inner surface of cavities is in operation at DESY since September 2008. More than 20 prototype nine-cell cavities for the European XFEL have been inspected. The unique illumination system combined with the optical sensors allows for the in-situ search of surface defects in high resolution. Such defects may limit the gradient when causing a breakdown of the superconducting state (quench). The comparison of features detected in the optical inspection and hotspots from the temperature mapping during RF-measurements give evidence for correlations. Consecutive inspections of cavities in different stages of the surface preparation process monitor the evolution of surface defects. There are examples for defects traced from the untreated surface condition to the RF-test with temperature map, which identify the defect as the quench location.
SOLEIL, Gif-sur-Yvette
At SOLEIL, the production of high brilliant photon beams with adjustable polarization is achieved by means of Advanced Planar Polarized Light Emitter-II (APPLE-II) undulators. The HU36 is a short period high field APPLE-II type undulator with 36 mm period and 0.8 T peak field at a minimum gap of 11 mm. The HU36 circularly polarized radiation ranges from 2 keV to 5 keV, while the planar one extends up to 10 keV. High harmonic radiation (up to the 13th) is required to reach such high energy; therefore a small RMS phase error is needed. To enable closing the gap at 11 mm, the HU36 is planned to be installed in a short section where the large horizontal beta function imposes constraining tolerances on the integrated field errors. However at low period and high field, the magnet holders, commonly used at SOLEIL to maintain magnets on the girders, experience mechanical deformation due to the large magnetic forces. This results in the variation of field integrals when the shift between girders is changed. Solutions to minimize these errors are discussed and finally the HU36 magnetic performances are reviewed.
Karlsruhe Institute of Technology (KIT), Karlsruhe
BNG, Würzburg
A 1.5 m long superconducting undulator with a period length of 15 mm is planned to be installed in ANKA middle 2010 to be the light source of the new beamline NANO for high resolution X-ray diffraction. The key specifications of the system are an undulator parameter K higher than 2 (for a magnetic gap of 5mm) and a phase error smaller than 3.5 degrees. In order to characterize the magnetic field properties of the superconducting coils local field measurements have been performed by moving a set of Hall probes on a sledge in a liquid helium bath: the results are reported.
Karlsruhe Institute of Technology (KIT), Karlsruhe
CERN, Geneva
BNG, Würzburg
STFC/RAL, Chilton, Didcot, Oxon
INFN/LNF, Frascati (Roma)
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire
Diamond, Oxfordshire
UMAN, Manchester
Rome University La Sapienza, Roma
MAX-lab, Lund
Max-Planck Institute for Metal Research, Stuttgart
One of the still open issues for the development of superconducting insertion devices is the understanding of the beam heat load. With the aim of measuring the beam heat load to a cold bore and the hope to gain a deeper understanding in the beam heat load mechanisms, a cold vacuum chamber for diagnostics is under construction. The following diagnostics will be implemented: i) retarding field analyzers to measure the electron flux, ii) temperature sensors to measure the total heat load, iii) pressure gauges, iv) and mass spectrometers to measure the gas content. The inner vacuum chamber will be removable in order to test different geometries and materials. This will allow the installation of the cryostat in different synchrotron light sources. COLDDIAG will be built to fit in a short straight section at ANKA. A first installation at the synchrotron light source DIAMOND is under discussion. Here we describe the technical design report of this device and the planned measurements with beam.
BNG, Würzburg
Karlsruhe Institute of Technology (KIT), Karlsruhe
Superconducting insertion devices (IDs) are very attractive for synchrotron light sources since they allow increasing the flux and/or the photon energy with respect to permanent magnet IDs. Babcock Noell GmbH (BNG) completed the fabrication of a 1.5 m long unit for ANKA at KIT. The period length of the device is 15 mm for a total of 100.5 full periods plus an additional matching period at each end. The key specifications of the system are: a K value higher than 2 for a magnetic gap of 5 mm, the capability of withstanding a 4 W beam heat load and a phase error smaller than 3.5 degrees. The field performance of the magnets has been qualified with liquid helium in a vertical dewar. As a result of this test the local correction coils have been installed and the magnets inserted in the final cryostat. During the factory acceptance test, the conduction cooling operation has been qualified and at the moment the undulator is ready to be tested at KIT. This paper describes the main features of the system and the results of the factory acceptance tests.
HSRC, Higashi-Hiroshima
More than a decade has past after the original quasi-periodic undulator (QPU) was proposed.* Until now, much work has been done to improve the QPU performance. One of the first most productive improvements was to introduce the quasi-periodicity in an electron trajectory by partially changing the field strength in a periodic undulator.** Also, a modification of creation theory of one-dimensional quasi-periodicity gave another degree of freedom to build this type of device.*** As the result, many different types of QPUs have been and will be installed in the synchrotron radiation facilities worldwide.**** In this paper, a new scheme of quasi-periodic undulator that has a different magnetic structure is proposed. This new QPU generates a slightly higher intensity radiation with higher harmonics pattern different from those of previous QPUs. This new scheme of QPU is achieved by introducing orthogonal field in each half-period in order to create additional phase delay of electron beam at certain positions predicted by the theory. We discuss about realistic magnetic configurations as well as possibilities and limitations of new-QPUs.
* Hashimoto, Sasaki, NIM A361, 611 (1995)
** Chavanne, et al, Proc EPAC98, p2213, Diviacco, et al, ibid, p2216
*** Sasaki, et al, Proc EPAC98, p2237
**** Steier, et al, Proc EPAC08, p2311
Hiroshima University, Faculty of Science, Higashi-Hirosima
HSRC, Higashi-Hiroshima
Different form conventional periodic undulators, the quasi-periodic undulator (QPU) can radiate irrational harmonics instead of rational harmonics. It suits with experiments that need highly monochromatic light after passing through the monochromator. For this reason, the QPU is used in many synchrotron radiation facilities all over the world. Recently, new type QPUs that generate radiation spectra different from those by conventional type QPU were proposed*,**. In principle, the shape of radiation spectrum from a new QPU is determined by magnetic field distribution having different quasi periodic pattern. However, calculated spectra using a realistic magnetic field are often different from those of theoretical expectation. In this paper, a detailed comparative study is conducted to examine why there are these differences, how to correct magnetic field to get predicted spectra that fit to the theory. In addition, a possibility of modifying the basis of theory is investigated. These results, new generation method of new quasi-periodicity, and magnetic field distribution to achieve the best performance are presented at the conference.
* S. Sasaki, Proceedings of PAC09, Vancouver, May, 2009.
** S. Sasaki, Proceedings of 6th Annual Meeting of Particle Accelerator Society of Japan (in Japanese).
The University of Liverpool, Liverpool
An analytic description of the synchrotron radiation from electrons with short-period helical trajectories is given by the Kincaid equation. A new code is under development which generates an analytical description of an arbitrary magnetic field, including non-linear and higher-order multipole (fringe field) components. The magnetic field map of a short-period undulator was modelled, using a 3-d finite element solver, and it's analytical field description has been used to compare the synchrotron radiation output from electrons with a 'realistic' trajectory in terms of the ideal analytic equations. The results demonstrate how small numerical inaccuracies in the particle tracking can lead to large inaccuracies in the calculated synchrotron output. The affects of the higher order field modes are studied which give additional insights into the radiation output from long undulator systems.
The University of Liverpool, Liverpool
Recent designs for third generation light sources commonly call for undulator systems with a total length of several hundreds of metres. Calculating the synchrotron output from bunches of charged particles traversing such a system using numerical techniques takes an unfeasibly long time even on modern multi-node computer clusters. Analytical formulae (i.e. the Kincaid Equation) provide a more rapid solution for an idealised system but necessarily fail to produce the non-ideal response which is under investigation. A new code is described which generates an analytic description of an arbitrary magnetic field and uses differential algebra and Lie methods to describe the particle dynamics in terms of series of transfer maps. The synchrotron output can then be calculated using arbitrarily large step size with no loss of accuracy in the trajectory. The code is easily adapted to perform parallel calculations on multi-core machines. Examples of the radiation output from several long magnet systems are described and the performance is assessed.
BNL, Upton, Long Island, New York
Various magnet sorting strategies have been used to minimize trajectory and phase errors in undulators, ranging from intuitive pairing of stronger and weaker magnets, to full 3D FEM simulation with actual Helmholtz coil magnet data. We present a simpler approach, first deriving trajectory displacement, kick angle and phase error signatures of each component of magnetization error from a 3D Radia* undulator model. Then, for a given sequence of magnets, the trajectory and phase profiles are computed by cumulatively summing the scaled displacements and phase errors. The rms error is then minimized by swapping magnets according to one's favorite optimization method. A fast, simple magnet swapping algorithm, implemented in Mathematica, is described. 100,000 iterations take only minutes, so dozens of solutions can be compared. This approach was applied recently at NSLS to a short in-vacuum undulator, which required no trajectory or phase shimming. We also obtain trajectory and phase error signatures of some mechanical errors, to guide "virtual shimming" and specifying mechanical tolerances. Finally, multipole signatures of some simple inhomogeneities are modeled.
* O. Chubar, P. Elleaume, J. Chavanne, "A 3D Magnetostatics Computer Code for Insertion Devices", SRI97 Conference August 1997, J. Synchrotron Rad. (1998). 5, 481-484
KEK, Ibaraki
Osaka University, Graduate School of Engineering, Osaka
RLNR, Tokyo
Magnets of the synchrotron accelerator which extracts the accelerated beams are excited by pulse operation power supply, and then the load fluctuation should be a severe problem. An energy storage system, such as SMES, fly-wheel generator so far, will be required for compensating the pulse electric power, and reducing the disturbances of the connected power line. The system is also expected to protect the instantaneous voltage drop and contributes the reliability of the storage ring. Present status of R & D and the features for the energy storage systems are discussed. The application of the energy storage systems to synchrotrons for the medical use is described. The compensation of the typical pulse electric power of the synchrotron for the cancer therapy is studied.
JAEA, Ibaraki-ken
In J-PARC RCS, horizontal closed orbit distortion (COD) which is ±2 or 3mm in amplitude was observed all over the ring. Main component of the horizontal COD is 1kHz, phase variation period about 140 seconds. This paper demonstrates phase variation of the 1kHz horizontal COD caused by switching ripple from dipole magnet power supply. To suppress the phase variation of the horizontal COD, switching timing of the dipole magnet power supply was synchronized J-PARC timing system.
RCNP, Osaka
The ordinary electric circuits produce and receive electromagnetic noise. The noise is a problem for stable operation of synchrotron accelerators. We do not know the origin of the noise generation due to the lack of electric circuit theory, which takes into account the noise sources. The proper treatment of electric circuit together with noise requires a proper knowledge of multiconductor transmission-line theory. We have developed a new multiconductor transmission-line theory in which we are able to describe the performance of multiconductor transmission-line system*. In this theory, it is essential to use the coefficients of potential instead of capacities and the introduction of the normal and common modes. After understanding the multiconductor transmission-line theory, we propose the introduction of the middle line (three lines) and symmetric arrangements of electric loads**. The use of this concept made the J-PARC MR successful in operation.
* H. Toki and K. Sato, J. Phys. Soc. Jpn 78 (2009) 094201.
** K. Sato and H. Toki, Nucl. Inst. Methods A565 (2006) 351.
CELLS-ALBA Synchrotron, Cerdanyola del Vallès
CITCEA-UPC, Barcelona
ALBA is a 3 GeV third generation synchrotron light source under construction in Spain. The injection system is composed of a 100 MeV Linac as pre-injector followed by a full energy booster synchrotron. The booster requires AC power converters operating at 3.125 Hz with a sinusoidal current waveform. All converters are switched mode with full digital regulation and a common control interface. The design specifications have been demonstrated and early tests on the Booster commissioning with beam will be presented
CELLS-ALBA Synchrotron, Cerdanyola del Vallès
ALBA is a 3 GeV third generation synchrotron light source under construction in Spain. The injection system is composed of a 100 MeV Linac as pre-injector followed by a full energy booster synchrotron which shares the same tunnel as the storage ring. With a circumference of 249.6 m and a magnetic lattice based on combined magnets an emittance of 9 nm.rad has been predicted. At present time we are in an intensive sub-system commissioning testing with the aim to start the commissioning with beam early in January 2010.
NSRRC, Hsinchu
The purpose of this paper is to estimate the conductive Electromagnetic Interference (EMI) from magnet power supply in NSRRC. A LISN system was conducted to measure the EMI spectrum of power supply. The different frequency range of conductive EMI was measured. For the future TPS(Taiwan Photon Source) power supply design, the EMI signals must be lower than TLS kicker. Therefore reducing and eliminating the interference of electromagnetic waves will be a very important issue. A filter and shielding method were used to test the effects of reducing EMI. The EMI prevention scheme will be used in the future.
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken
3 GeV rapid cycling synchrotron (RCS) of J-PARC accelerates proton beams from the 181 MeV up to 3 GeV. The RCS injects the beam to the Main Ring and transports it to the muon production target and neutron production target in the Materials and Life Science Experimental Hall. Proton beams in the RCS are fast extracted by kicker magnets at the repetition rate of 25 Hz. The rise time of the magnetic field is approximately 260 ns due to the propagation time through the coaxial cable and the kicker magnet itself. The flat-top length of it is required to 840 ns in order to extract two beam bunches. Pulse forming lines (PFL) and thyratrons are used to make the rise time and the flat-top, at the maximum charging voltage of 80 kV. Two thyratrons, which is a CX1193C made by e2V Ltd., are used for a power supply. 16 thyratrons are used in the eight power supplies of the kicker system. Since thyratrons are gaseous discharge switching devices, they often make misfire or self-breakdown in several hours. In this paper, present status of operation and voltage adjustment method of the reservoir and cathode heater power supply of the thyratrons in the kicker system are described.
CERN, Geneva
The vertical beam dump system of the CERN Super Proton Synchrotron (SPS) uses two matched magnets with an impedance of 2 Ω and combined kick strength of 1.152 Tm at 60 kV supply voltage. For historical reasons the two magnets are powered from three 3 Ω pulse forming networks (PFN) through three thyratron-ignitron switches. Recently flashovers were observed at the entry of one of the magnets, which lead, because of the electrical coupling between the kickers, to a simultaneous breakdown of the pulse in both magnets. To improve the reliability an upgrade of the system was started. In a first step the radii of surfaces at the entry of the weak magnet were increased, and the PFN voltage was reduced by 4 %; the kick strength could be preserved by reducing the magnet termination resistance by 10 %. The PFNs were protected against negative voltage reflections and their last cells were optimised. In a second step the two magnets will be electrically separated and powered individually by new 2 Ω PFNs with semiconductor switches.
CERN, Geneva
The main detector solenoid and associated magnets can have an important impact on the CLIC luminosity. These effects are discussed for different solenoid designs. In particular, the luminosity loss due to incoherent synchrotron radiation in the experiment solenoid and QD0 overlap is evaluated. The impact of the AntiDiD (Anti Detector integrated Dipole) on luminosity and compensated techniques on beam optic distortion are also discussed.
Imperial College of Science and Technology, Department of Physics, London
STFC/RAL/ISIS, Chilton, Didcot, Oxon
The international Muon Ionisation Cooling Experiment (MICE) is designed to provide a proof of principal of the ionisation cooling technique proposed to reduce the muon beam phase space at a future Neutrino Factory or Muon Collider. The pion production target is a titanium cylinder that is dipped into the proton beam of the Rutherford Appleton Laboratory's ISIS 800 MeV synchrotron. Studies of the particle rate in the MICE muon beam are presented as a function of the beam loss induced in ISIS by the MICE target. The implications of the observed beam loss and particle rate on ISIS operation and MICE data taking is discussed.
INFN/LNF, Frascati (Roma)
BINP SB RAS, Novosibirsk
In DAΦNE, the Frascati e+/e- collider, the crab waist collision scheme has been successfully implemented in 2008 and 2009. During the collision operations for Siddharta experiment, an unusual synchrotron damping effect has been observed. Indeed, with the longitudinal feedback switched off, the positron beam becomes unstable with beam currents in the order of 200-300 mA. The longitudinal instability is damped by bringing the positron beam in collision with a high current electron beam (~2A). Besides, we have observed a shift of ≈600Hz in the residual synchrotron sidebands. Precise measurements have been performed by using a commercial spectrum analyzer and by using the diagnostics capabilities of the DAΦNE longitudinal bunch-by-bunch feedback. This damping effect has been observed in DAΦNE for the first time during collisions with the crab waist scheme. Our explanation is that beam collisions with a large crossing angle produce a longitudinal tune shift and a longitudinal tune spread, providing Landau damping of synchrotron oscillations.
JASRI/SPring-8, Hyogo-ken
NewSUBARU/SPring-8, Laboratory of Advanced Science and Technology for Industry (LASTI), Hyogo
RIKEN Nishina Center, Wako
Transverse beam instabilities were suppressed with chromaticity modulation (CM)* in the electron storage ring, New SUBARU. The horizontal and vertical betatron tune spread inside a bunch were introduced by CM with synchrotron oscillation frequency driven by an AC sextuple magnet**, to obtain Landau damping of the coherent bunch motion. The tune spread in a bunch is usually introduced by octupole field, however, its high nonlinearity reduces the dynamic aperture. And usual feedback against instabilities work only on m=0 mode and it is not easy to be applied to hadron synchrotrons because of their varying revolution period. The CM scheme has not such disadvantages. The damping time of coherent motion excited by external kick was measured and was found as less than 1ms, one order faster than that without CM. To observe the effect on instabilities, we intentionally tuned an HOM in a cavity to excite a horizontal multi-bunch instability. The instability peak in the spectrum of the beam motion was vanished with CM turned on and the instability was suppressed. We also observed the increase of the threshold current of the vertical single-bunch mode-coupling instability by factor 3 with CM.
* T. Nakamura, Proc. of PAC'95, p.3100 (1995).
** T. Nakamura, et al., Appl. Superconduct., IEEE Trans. Vol. 18, p.326 (2008).
KEK, Ibaraki
KEK/JAEA, Ibaraki-Ken
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken
Magnetic alloy cavities are successfully used for J-PARC synchrotrons. These cavities generate much higher RF voltage than ordinary ferrite cavities. For future upgrades of J-PARC facilities, a higher field gradient is necessary. It was found that the characteristics of magnetic alloy is improved by a new annealing scheme under magnetic field. A large production system using an old cyclotron magnet is under construction for the J-PARC upgrade. The status of core development will be reported.
KEK/JAEA, Ibaraki-Ken
KEK, Ibaraki
JAEA/J-PARC, Tokai-mura
Several magnetic alloy cores of the RF cavities, which are installed in the 3 GeV rapid cycling synchrotron (RCS) of J-PARC have shown buckling after about two years operation. To find the reason, why the local deformation happened, we made a test setup. There we heat up MA cores in air by 500 kHz RF and measure the thermal deformation in order to collect information about the buckling process. The results obtained by comparing the expansion of cores made by different production methods are reported.
JAEA/J-PARC, Tokai-mura
KEK/JAEA, Ibaraki-Ken
KEK, Ibaraki
We have been operating the RF cavities loaded with MA cores with a high field gradient of more than 20 kV/m since October 2007. We have been measuring the RF cavity impedance at the shutdown periods, and we detected the impedance reductions of RCS RF cavities on January and June 2009. Taking out the RF cavities from the beam line and opening them, we found that many of cores showed a buckling at the inner radius. Also detachment of the epoxy coating intended to prevent rusting was observed. We report the detail of condition of MA cores and the relation between the impedance reduction and core condition.
USTC/NSRL, Hefei, Anhui
UW-Madison/SRC, Madison, Wisconsin
A radio frequency system with a higher-harmonic cavity will be used to increase the beam lifetime and suppress coupled-bunch instabilities of the upgrade Hefei Light Source. In the paper, the simulated results confirm that tuning in the harmonic cavity may suppresses the parasitic coupled-bunch instabilities. The higher-harmonic cavity has been designed and the calculated optimum lifetime increase ratio is 2.58.
KEK, Ibaraki
OHTSUKA, Tsukuba-shi
The MO (Matsumoto-Ohtsuka) -type flange is suitable for connection flanges of beam pipes for accelerators. The flange uses a metal gasket that exactly fits the aperture of the beam pipe, and has a small beam impedance. The flange can be applied to a complicated aperture. We developed a stainless-steel MO-type flange for a copper beam pipe with antechambers. Several beam pipes were installed in the KEKB B-factory positron ring and were tested using beams. No serious problem was observed up to a beam current of 1600 mA (~10 nC/bunch and ~6 ns bunch spacing). Based on experiences in the stain-less steel case, a possibility of employing copper-alloy and aluminum-alloy MO-type flange has been experimentally studied. They can mitigate the heating problems found in the case of stainless-steel flanges, and simplify the manufacturing procedure of beam pipes made of copper or aluminum alloy. Copper-alloy (CrZrCu) flanges show a comparable vacuum sealing property to the stainless-steel one, and several beam pipes with this flange has been successfully installed in the KEKB. The R&D on aluminum-alloy (A2219 and A2024) flanges has recently started, and a promising result was obtained.
NSRRC, Hsinchu
Aluminum alloy was chosen for vacuum chamber materials and oil-free manufacturing, ozone water cleaning processes were used to obtain ultrahigh vacuum in TPS vacuum system. The storage ring vacuum system is divided into 24 unit cells and there are 6 ionized gauges, 8 ion pumps and 6 gate valves in one cell. An interlock system is designed to monitor and control the vacuum devices to keep ultrahigh vacuum. Because the vacuum chamber is exposed to the high power synchrotron radiation directly, cooling water and temperature statuses on the vacuum chamber are also monitored. The hardware, software and their associated interlock logic will be described.
GSI, Darmstadt
ITEP, Moscow
The heavy ion synchrotron SIS-100 will play a key role within the future FAIR project underway at GSI. Although this synchrotron is optimized for fast extraction, also slow extraction will be used. Slow extraction is based on beam excitation due to a third order resonance. The spread in the particle momenta generating a tune spread causes particle loss leading to an irradiation of the machine especially in a high-current operation. A major part of the losses is assumed to occur at the electro-static separator. In the present study we apply a tracking method to model the extraction process to predict the losses, where, in a first step, high current effects are not taken into account.
GSI, Darmstadt
The present heavy ion synchrotron SIS-18 will be upgraded to be used as a booster for further synchrotrons being part of the FAIR project underway at GSI. We present a technique to measure the acceptance of an accelerator based on the extension of a previous method by the measurement of particle loss which we have applied to SIS-18. Here, we used an RF voltage to transversally excite a coasting heavy ion beam. The resulting transverse growth of the beam leads to particle loss when the beam width exceeds the limiting aperture. The acceptance has been determined from the time evolution of the beam current measured after particle have started to hit the aperture.
INFN/LNF, Frascati (Roma)
CNAO Foundation, Milan
CERN, Geneva
University of Pavia, Pavia
The National Centre for Oncological Hadrontherapy (CNAO) is the first Italian centre for the treatment of patients affected by tumours with proton and carbon ions beams. Its status and commissioning results are presented in this conference in several papers. The synchrotron beam extraction is based on the use of a betatron core. The possibility of using the RF-knockout method as alternative system is being investigated, trying to optimise the performances with the already present hardware and minimum upgrades. A multiparticle tracking program has been written to simulate the beam dynamics during the extraction of the synchrotron, and to optimise the parameters of the radio frequency system. Two types of signals have been studied in order to obtain a constant spill with the minimum ripple: a carrier wave with a frequency and amplitude modulation, and a noise at a given range of frequencies modulated in amplitude. The results of the optimisation and the parameters of the proposed system are presented.
CERN, Geneva
TU Vienna, Wien
EBG MedAustron, Wr. Neustadt
The MedAustron facility, to be built in Wiener Neustadt (Austria), will provide protons and different types of ions for cancer therapy and research. Ten different types of bumpers, septa and kickers will be used in the low energy beam transfer line, the synchrotron and the high energy extraction lines. They are presently being designed in collaboration with CERN. Both 2D and 3D finite element simulations have been carried out to verify and optimize the field strength and homogeneity for each type of magnet and, where applicable, the transient field response. The detailed designs for the injection and dump bumpers, the magnetic septa and the fast chopper dipoles are presented. A novel design for the electrostatic septa is outlined.
LNLS, Campinas
Diffusion bonding is a welding process where the main mechanism responsible for the union of the materials is the interdiffusion of atoms across the joint surface, even in solid state. The objective of the present work is to produce bonded joints that could be used in vacuum components for particle accelerator. Is this work was produced a welding joint between two dissimilar materials: oxygen free copper and AISI 316 L stainless steel. Each sample was bonded in vacuum (10-5mbar) at a temperature range between 800 and 900°C, pressure of 12MPa and holding times between 30 and 60min. Optical microscopy, scanning electron microscopy, mechanical testing and helium leak test were used to study the bond quality. The images obtained by optical and electron microscopy revealed good quality interfaces without the presence of defects and pores. All samples are tested through the helium leak test and were approved. The results indicate great potential to use this process in the manufacturing of components suitable for ultra high vacuum, for application in the design of new LNLS storage ring.
NSRRC, Hsinchu
The RF power source using solid-state amplifier for accelerator application has become popular in recent years. The amplifiers array using power divider and power combiner could obtain equivalent power level as those using klystron or IOT. Such solid-state RF power source also has the advantage of easy maintenance, low cost, low DC power voltage and high flexibility. The development of solid-state power amplifier module at 499.65 MHz using the latest RF power chip has been built to have the power level of 900 Watts with above 60% efficiency of single power module. The more power that one module can provide, the less number of modules would be required under the same total output power of amplifiers array. Thus, the construction of a transmitter by solid-state technique for RF system would be less complex for easy maintenance.
NSRRC, Hsinchu
NTUT, Taipei
The stability of air temperature in the storage ring tunnel is one of the most critical factors. Therefore, a series of air conditioning system upgrade studies and projects have been conducted at the Taiwan Light Source (TLS). The global air temperature variation related to time in the storage ring tunnel has been controlled within ±0.1 degree C for years. This study is aimed at more precise temperature control. Some temperature control schemes are applied on this study. We also performed computational fluid dynamics (CFD) to simulate the flow field and the spatial temperature distribution in the storage ring tunnel.
NSRRC, Hsinchu
National Synchrotron Radiation Research Center (NSRRC) in Taiwan has finished an open bid about utility system for Taiwan photon source (TPS). The detail design and criteria of the utility cooling system, including cooling water and air conditioning system, have also been considered and confirmed. From controls to facility, all devices were designed and optimized to meet critical requirements of high reliability and stability. Besides, the paper mainly focuses on thermal load evaluation and removes to achieve the best efficiency and performance of system. The brand new system structure and control strategy also be realized.
NSRRC, Hsinchu
Previously, the Taiwan Light Source (TLS) has proven that the temperature stability of de-ionized cooling water is one of the most critical factors of electron beam stability. A series of efforts were devoted to these studies and promoted the temperature stability of the de-ionized cooling water system within ±0.1°C. Further, a high precision temperature control ±0.01°C has been conducted to meet the more critical stability requirement. Using flow mixing mechanism and specified control philosophy can minimize temperature variation effectively. The paper declares the mechanism through simulation and verifies the practical influences. The significant improvement of temperature stability between cooling devices and de-ionized water are also presented.
CERN, Geneva
SLAC, Menlo Park, California
In this paper, we estimate the emittance growth in the LHeC recirculating Linac, the lattice design of which is presented in another paper of IPAC10 proceedings. The possible sources for emittance growth included here are: energy spread from RF acceleration in the SRF (superconducting RF) linac plus large chromatic effects from the lattice, synchrotron radiation (SR) fluctuations in the recirculating arcs. 6-D multi-particle tracking is launched to calculate the emittance from the statistical point of view. The simulation results are also compared with a theoretical estimation.
SDU, Isparta
Ankara University, Faculty of Engineering, Tandogan, Ankara
Gazi University, Faculty of Arts and Sciences, Teknikokullar, Ankara
Ankara University, Faculty of Sciences, Tandogan/Ankara
Dumlupinar University, Faculty of Science and Arts, Kutahya
The status and road map of Turkish Accelerator Center (TAC) project is explained. TAC project is in third phase after feasibility and conceptual design phases with support of State Planning Organisation (SPO) of Turkey that the main aim of this phase is to complete of technical design report of TAC and to establish the first (test) facility. The first facility is planned as superconducting electron linac based IR FEL and bremsstrahlung facility. Third phase will be completed in 2013. It is planned that TAC will include a linac on ring type electron positron collider as a super charm factory, third and fourth generation light sources (SR and SASE FEL) and a proton facility. TAC collaboration is an inter-university collaboration of ten Turkish Universities under the coordination of Ankara University and TAC is a national project with international collaboration. In this study, the status of the project and the road map is explained with some results from design and construction studies.
NewSUBARU/SPring-8, Laboratory of Advanced Science and Technology for Industry (LASTI), Hyogo
A simple analytical formula for the transient bunch lengthening by betatron motion along bending sections is explained. The formula describes a longitudinal and transverse coupling for a single-pass line, which is obtained as an extension of the formula for a storage ring. The bunch lengthening is expressed by a product of three factors: the square root of horizontal betatron emittance, a betatron phase factor, and the square root of the H-function, in other words, dispersion action. That effect had been calculated in many reports concerning with sub-ps electron bunch generation, such as the laser-bunch slicing, the vertical bunch deflection by a crab cavity, and the beam transport along a quasi-isochronous bending arcs. In these works the transfer matrix elements, R15 and R25, had been calculated for each of various conditions. On the contrary, our simple and general analytical formula gives a good foresight to understand the observed phenomena and for an easy optimization of parameters of bending arcs.
CERN, Geneva
The CERN Proton Synchrotron has been continuously improving its beam performances since 1959. The working point parameters of the accelerator are mainly controlled by dedicated windings installed on the poles of the main combined function magnets. In 2007, the power supplies of these windings were renovated and extended from three to five independent groups, allowing exploration of new working point settings. This configuration offers the flexibility of several adjustment strategies such as leaving one current free or to control an additional physical parameter, like Q''h. A non-linear chromaticity measurement campaign, at different beam energies, resulted in matrices defining the relationship between the five pole face winding currents and the four beam parameters Qh, Qv, Xih, and Xiv. Each cell of these matrices was fitted against energy. The final result is a single matrix which is now used by the operational software to trim the working point. This paper summarises this measurement campaign by presenting the resulting matrix with a brief overview of the adjustment tools and strategy. Furthermore a few future possible benefits of this control enhancement will be discussed.
CERN, Geneva
BNL, Upton, Long Island, New York
A software package has been developed for the LHC on-line optics measurement and correction. This package includes several different algorithms to measure phase advance, beta functions, dispersion, coupling parameters and even some non-linear terms. A Graphical User Interface provides visualization tools to compare measurements to model predictions, fit analytical formula, localize error sources and compute and send corrections to the hardware.
CANDLE, Yerevan
A method of beam energy spread and synchrotron tune measurements based on the analysis of transverse decoherence\recoherence signal of kicked beam is presented. As an illustration the beam energy spread was extracted for the SLS storage ring.
BNL, Upton, Long Island, New York
CERN, Geneva
The adiabaticity of the AC dipole might be compromised by noise or unwanted frequency components in its signal. An effort has been put to characterize and optimize the signal quality of the LHC AC dipoles. The measured signal is used in realistic simulations in order to evaluate its impact on beam dynamics and to ultimately establish safe margins for the operation of the LHC AC dipoles.
PSI, Villigen
The filling pattern can have a big impact in the effective bunch lengthening of a passive 3rd harmonic system and as a consequence in the Touschek component of the beam lifetime. Using a longitudinal dynamics tracking code, in which the effects of the accelerating system and the 3rd harmonic system are taken into account, we can calculate the synchronous phase drift caused by the transient beam-loading and thus the effective bunch increase for several different filling patterns. In this paper we present a comparison between simulation and measurements for the SLS.
ANL, Argonne
APS has started a program of upgrading old BPM electronics to new FPGA-based devices. We present here the use of such BPMs for online measurement of betatron tunes during topup operation. In topup injection, the stored beam is kicked and experiences betatron oscillations that can be used for online monitoring of the betatron tunes. Also, due to kicker waveform time dependence, different bunches experience kicks of different amplitude. By collecting data from different bunches one can also monitor tune shift with amplitude. In the case of APS, the matter is complicated by the very fast decoherence of oscillations. We describe methods used to derive tunes and present results of online monitoring.
CERN, Geneva
The CLOUD Project, where a high-energy physics accelerator is being used to study atmospheric and climate science for the first time, will be described.