HMI, Berlin
Charite, Berlin
HZB, Berlin
The ion beam laboratory ISL at the Hahn-Meitner-Institute (HMI) Berlin supplied light and heavy ion beams for research and applications in solid state physics, industry, and medicine. Since 1998, eye tumours are treated with 68 MeV protons in collaboration with the University Hospital Benjamin Franklin, now Charité - Campus Benjamin Franklin. In autumn 2004 the board of directors of the HMI decided to close down ISL at the end of 2006. In December 2006, a cooperation contract between the Charité and the HMI was signed to assure the continuity of the eye tumour therapy, at the moment the only facility in Germany. The accelerator operation will be continued with reduced man-power, requiring changes in the set-up of the accelerators. A new, facile injector for protons is foreseen. Increasing the reliability will be a key issue. The last two years of operation of ISL as a full multi-purpose accelerator will be shown and examples of the research work will be demonstrated. The conversion of a multi-ion, variable energy accelerator to a dedicated accelerator for eye tumour therapy will be discussed.
The Helmholtz-Zentrum Berlin für Materialien und Energie has been formed by the merger of the Hahn-Meitner-Institut Berlin and the Berliner Elektronenspeicherring-Gesellschaft für Synchrotronstrahlung
GSI, Darmstadt
The FAIR SIS100 accelerator at GSI Darmstadt will be equipped with fast ramped superconducting magnets. The high current Uranium beam modes with intermediate charge states, require ultra low vacuum pressures that can be achieved in long term operation only by cold beam pipes acting as a cryopump with stable temperatures well below 12 K for all operating cycles. The straightforward layout for reliable cooling usually conflicts with an efficient design for fast ramped superconducting accelerator magnets, strongly affected by AC loss generation, field distortion and mechanical stability problems. A full functional vacuum chamber design for SIS 100 has to take into account all these conflicting boundary conditions and trade off between mechanical stability, acceptable field distortions, AC loss minimisation and achievable temperatures. We discuss the cooling conditions for the dipoles and for the beam pipe including first test results. The analysis of the principal design aspects for the vacuum chamber with respect to the magnets operation parameters and an integral design approach are given. We present a technological feasible solution for model testing and full scale manufacturing.
BNL, Upton, Long Island, New York
CERN, Geneva
Using the vernier scan or Van der Meer scan technique, where one beam is swept stepwise across the other while measuring the collision rate as a function of beam displacement, the transverse beam profiles, the luminosity and the effective cross section of the detector in question can be measured. This report briefly recalls the vernier scan method and presents results from the first RHIC polarized proton run at 250 GeV/beam in 2009.
GSI, Darmstadt
FIAS, Frankfurt am Main
After partially completing the upgrade program of SIS18, the number of intermediate charge state heavy ions accelerated to the FAIR booster energy of 200 MeV/u, could be increased by a factor of 50. Meanwhile, more than 1010 Uranium ions with charge state 27+ have been accelerated with moderate beam loss by ionization and reasonably stable residual gas pressure conditions. The specific challenge for the SIS18 booster operation is the high cross section for ionization due to the low charge state in combination with gas desorption processes and the dynamic vacuum pressure. Especially for this operation mode which is requied to match the intensity requirements for FAIR, an extended upgrade program of SIS18 is presently ongoing and partially completed. The achieved progress in minimizing the ionization beam loss underlines that the chosen technical strategies described in this report are appropriate.
JINR, Dubna, Moscow Region
BINP SB RAS, Protvino, Moscow Region
JINR/LHE, Moscow
The 'Nuclotron-M' project started in 2007 is considered as the key point of the first stage of the NICA/MPD project. General goal of the 'Nuclotron-M' project is to prepare all the systems of the Nuclotron for its long and reliable operation as a part of the NICA collider injection chain. Additionally the project realization will increase the Nuclotron ability for realization of its current experimental program. Results of the last runs of the Nuclotron operation are presented.
JINR, Dubna, Moscow Region
JINR/LHE, Moscow
The Nuclotron-based Ion Collider fAcility (NICA) is the new accelerator complex being constructed at JINR aimed to provide collider experiments with heavy ions up to uranium at the center of mass energy from 4 to 11 GeV/u. It includes 6 Mev/u linac, 600 MeV/u booster, upgraded SC synchrotron Nuclotron and collider consisting of two SC rings, which provide average luminosity of the level of 1027cm-2s-1.
IAP, Frankfurt am Main
GSI, Darmstadt
At the Institute for Applied Physics a superconducting CH-Cavity (Crossbar H-Mode) has been developed. It is the first multi-cell drift tube cavity for the low and medium energy range of proton and ion linacs. A 19 cell, β = 0.1 prototype cavity has been fabricated and tested successfully with a voltage of 5.6 MV corresponding to gradients of 7 MV/m. The construction of a new superconducting 325 MHz 7-gap CH-cavity has started. This cavity has an optimized geometry with respect to tuning possibilities, high power RF coupling, minimized end cell lengths and options for surface preparation. Static tuning is carried out by small niobium cylinders on the girders. Dynamic tuning is performed by a slow bellow tuner driven by a step motor and a fast bellow tuner driven by a piezo. Additional thermal and mechanical simulations have been performed. It is planned to test the cavity with a 10 mA, 11.4 AMeV (β = 0.158) beam delivered by the Unilac at GSI. Another cavity (f = 217 MHz, β = 0.059) is currently under development for the cw Heavy Ion Linac at GSI. It is the first of nine sc CH-Cavities planned for this project covering an energy range from 1.4 to 7.3 AMeV.
GSI, Darmstadt
Nagaoka University of Technology, Nagaoka, Niigata
FZJ, Jülich
JINR, Dubna, Moscow Region
The stochastic cooling is employed to reduce the momentum spread of accelerated 2 GeV proton beam at COSY. In addition the barrier voltages are successfully used to compensate the mean energy loss of the beam due to the thick internal target such as pellet target. To analyze the experimental results at COSY, we have developed the particle tracking code which simulate the particle behavior under the influences of stochastic cooling force, Schottky diffusion, thermal diffusion and IBS effects. The synchrotron motion due to the RF fields are included with 4th order symplectic way. The simulation results are well in agreement with the observed cooling process for the case of barrier voltage as well as RF field of harmonic number=1. In the present paper, the systematic analysis of the experimental results with use of the developed tracking codes are described. In addition the process of short bunch formation at the heavy ion collider at NICA project is investigated with use of the stochastic cooling. In that case the strong IBS effects are main limiting factor of making and keeping the short bunch as well as the space charge effects. Details of the simulation study will be presented.
BNL, Upton, Long Island, New York
The Relativistic Heavy Ion Collider (RHIC) operates with either ions or polarized protons. After increasing the heavy ion luminosity by two orders of magnitude since its commissioning in 2000, the current luminosity upgrade program aims for an increase by another factor of 4 by means of 3D stochastic cooling and a new 56 MHz SRF system. An Electron Beam Ion Source is being commissioned that will allow the use of uranium beams. Electron cooling is considered for collider operation below the current injection energy. For the polarized proton operation both luminosity and polarization are important. In addition to ongoing improvements in the AGS injector, the development of a new high-intensity polarized source has started. In RHIC a number of upgrades are under way to increase the intensity and polarization transmission to 250 GeV beam energy. Electron lenses will be installed to partially compensate the head-on beam-beam effect.
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.
TEMF, TU Darmstadt, Darmstadt
GSI, Darmstadt
Electron clouds generated by residual gas ionization pose a potential threat to the stability of the circulating heavy ion beams in the existing SIS-18 synchrotron and in the projected SIS-100. The electrons can potentially accumulate in the space charge potential of the long bunches. As an extreme case we study the accumulation of electrons in a coasting beam under conditions relevant in the SIS-18. Previous studies of electron clouds in coasting beams used Particle-In-Cell (PIC) codes to describe the generation of the cloud and the interaction with the ion beam. PIC beams exhibit much larger fluctuation amplitudes than real beams. The fluctuations heat the electrons. Therefore the obtained neutralization degree is strongly reduced, relative to a real beam. In our simulation model we add a Langevin term to the electron equation of motion in order to account for the heating process. The effect of natural beam fluctuations on the neutralization degree is studied. The modification of the beam response function as well as the stability limits in the presence of the electrons is discussed. Finally we will also address the electron accumulation in long bunches.
IMP, Lanzhou
Two electron cooling devices have been used at HIRFL-CSR in order to provide high quality heavy ion beams for nuclear and atomic research. The momentum spread is one of the most important characteristics of the beam quality. At HIRFL-CSR, the momentum spread is measured directly with the aid of longitudinal Schottky spectra system. In this paper, the measurements for various ion species are presented. At relatively high intensity, longitudinal Schottky spectra is double peak due to collective phenomena and the momentum spread can be obtained by fitting the spectra. The dependence of momentum spread on stored particle number is proportional to N**a. Moreover, the heating factor was investigated after switching off the electron cooling. The residual gas scattering, the intrabeam scattering and instabilities are studied according to the measured data.
GSI, Darmstadt
The FAIR accelerator project at GSI should increase the intensity of primary proton and heavy ion beams by up to two orders of magnitude, relative to the existing GSI facility. In addition to the design of the new synchrotron SIS-100 and the storage rings, the intensity upgrade of the SIS-18 synchrotron plays a key role for the FAIR project. Recently a new record beam intensity for intermediate charge state uranium ions has been achieved in the SIS-18. Still several challenges related to beam intensity effects and phase space conservation have to be mastered in order to reach the beam parameters required for the injection into SIS-100. In SIS-100 beam loss control and machine protection are of major concern. Lost energetic heavy ions can cause a more severe damage of accelerator components than the corresponding amount of protons. Gradual beam loss of energetic ions is expected to occur in SIS-100 mainly during slow extraction of intense beams. Coherent transverse instabilities induced by the beam pipe impedance are a potential cause of fast beam loss and emittance increase. Cures and protection measures together with the result of simulation studies will be summarized.
Peking University, School of Physics, Beijing
PKU/IHIP, Beijing
This paper introduce a possible solution to improve the efficiency of the very low beta SC accelerating structure, via extending the gaps number of 4-gap interdigital QWR by doubling its stems number. The new cavity is a 8-gap QWR, which is comprised of two parallel TEM resonant lines operating in opposing phase from each other. It maintains the 4-gap QWR's good EM parameters and enables the use of demountable flange. The more important advantage is the potential improvement of efficiency. According to a preliminary estimation of longitudinal dynamics, the 8-gap QWR could stably accelerate heavy ion at the velocities 0.01<v/c<0.05.
JLAB, Newport News, Virginia
PKU/IHIP, Beijing
NSU, Newport News, Virginia
Field emission is still one of the major obstacles facing Nb superconducting radio frequency (SRF) community for allowing Nb SRF cavities to reach routinely accelerating gradient of 35 MV/m that is required for the international linear collider. Nowadays, the well know low temperature backing at 120 oC for 48 hours is a common procedure used in the SRF community to improve the high field Q slope. However, some cavity production data have showed that the low temperature baking may induce field emission for cavities treated by EP. On the other hand, an earlier study of field emission on Nb flat samples treated by BCP showed an opposite conclusion. In this presentation, the preliminary measurements of Nb flat samples treated by BEP, EP, and BCP via our unique home-made scanning field emission microscope before and after the low temperature baking are reported. Some correlations between surface smoothness and the number of the observed field emitters were found. The observed experimental results can be understood, at least partially, by a simple model that involves the change of the thickness of the pent-oxide layer on Nb surfaces.
* L.C. MacIntyre, R. Ike, and A.T. Wu, 2005, unpublished
NIRS, Chiba-shi
The development of the screen monitor system (SCN) at the Heavy Ion Medical Accelerator in Chiba (HIMAC) comprises the surveillance of the carbon beam. In the three-dimensional scanning system for the carbon therapy, the beam qualities, i.e., position, size and intensity of the beam, play a significant role for the patient's treatment. Therefore, we designed a semi-nondestructive monitoring system located on the the high-energy beam transport line to monitor the beam qualities by using a thin fluorescent screen and a high-speed charge-coupled device. The beam position and profile were obtained from the light emitting distribution of the screen. The SCN was checked on the prototype scanning system at HIMAC and succeeded to monitor the beam real-time in steps of about 10 msec, corresponding to a 100 Hz sampling rate. The developments steps will focus toward a operation at HIMAC's new therapy facility extension, recently. In the conference, we would like to report on details of the automatic beam tuning before starting the treatment and the interlock system during therapy using the SCN.
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.
IMP, Lanzhou
CSR has recently made significant progress in commissioning a variety of light to heavy ion in the cooler ring. Also, carbon therapy was successfully carried out. A significant achievement is the energy modulation extraction using slow extraction realizing 3D conformal treatment.
ITEP, Moscow
GSI, Darmstadt
Terra Watt Accumulator project (ITEP-TWAC) is aiming the accumulation of an ion beam accelerated up to 0.7 GeV/u in a storage ring providing intensity of heavy ions up to 10 power 12 particles per pulse for experiments on heavy ion beam-plasma interaction. For advanced experiments on high energy density physics the hollow cylindrical target is needed. A new method for RF rotation of the ion beam is applied for reliable formation of the hollow cylindrical beam. A principle of fast beam rotation by using a system of the multi-cell RF deflectors is considered in this paper. A four-cell H-mode deflecting cavity operating at the frequency of 298 MHz has been developed; similar 1.5 m long cavities being applied for both x- and y- directions. The shape of the deflecting electrodes has been optimized in order to provide the uniform deflection over the whole aperture taking into account both electric and magnetic components of the RF field. A deflecting system and a focusing quadrupole triplet applied to the beam with the energy of 450 MeV/u and normalized transverse emittance of 10*pi mrad*mm may form the quasi-hollow configuration with the inner radius up to 1.5 mm and thickness of 1 mm.
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.
RIKEN Nishina Center, Wako
SHI Accelerator Service Ltd., Tokyo
The next generation heavy ion accelerator facility, such as the RIKEN RIBF, requires great variety of high charged heavy ions with a magnitude higher beam intensity than currently achievable. In the last decade, performance of the ECR ion sources has been dramatically improved with increasing the magnetic field and RF frequency to enhance the density and confinement time of plasma. Furthermore, the effects of the key components (magnetic field configuration, gas pressure etc) on the ECR plasma have been revealed. Such basic studies give us how to optimize the ion source structure. Based on these studies and the technology, we successfully constructed the new 28GHz SC-ECRIS which has a flexible magnetic field configuration to enlarge the ECR zone and to optimize the field gradient at ECR point. In the test experiment, we obtained the direct evidence that the field gradient and the zone size strongly affect the beam intensity. It concludes that the gentler field gradient and large ECR zone size gives intense beam of highly charged heavy ions from ECR plasma. In this contribution, we report the systematic study of these effects on the beam intensity of highly charged heavy ions.
Department of Energy Sciences, Tokyo Institute of Technology, Yokohama
BNL, Upton, Long Island, New York
Kyushu University, Department of Applied Quantum Physics and Nuclear Engineering, Fukuoka
The Electron Beam Ion Source (EBIS) project at Brookhaven National Laboratory is a new heavy ion pre-injector for Relativistic Heavy Ion Collider (RHIC) and NASA Space Radiation Laboratory science programs. An important requirement for EBIS is an ion source capable of efficiently providing a variety of heavy ion species to many users within short period of time. In that respect, Laser Ion Source (LIS), which can supply many heavy ion species from solid targets, is a good candidate for RHIC-EBIS, however, LIS has an issue to be resolved. This is the requirement of limited current in low energy beam transport. LIS in the condition that laser power density is low, is expected to provide limited current with long pulse length. The discussions of the experimental results are presented.
TU Darmstadt, Darmstadt
GSI, Darmstadt
The central accelerator SIS100 of the FAIR-facility will provide high intensity, intermediate charge state heavy ion beams. In order to assure a reliable operation with the intermediate charge states, a special synchrotron design, including ion catcher system had to be developed. Intermediate charge state heavy ions suffer from high cross sections for ionization. Due to the dedicated synchrotron layout, ions which have been further stripped by collisions with residual gas atoms are not lost uncontrolled onto the beam pipe but are caught by the ion catcher system in the cryogenic arcs. The construction and test of a cryo-catcher prototype at GSI is a workpackage of the EU-FP7 project COLMAT. A prototype catcher including cryostat will be set-up at GSI to perform measurements with heavy ion beams of the heavy ion synchrotron SIS18.
GSI, Darmstadt
TU Darmstadt, Darmstadt
INFIM, Bucharest
Within the frame of the EuCARD program, the GSI Darmstadt is performing accelerator R&D in workpackage 8: ColMat. The effort is focused on materials important for building the FAIR accelerator facility at GSI and the LHC upgrade at CERN. Accelerator components and especially protection devices have to be operated in high dose environments. The radiation hazard occurs either by the primary proton and ion beams or the secondary radiation. Detailed numerical simulations have been carried out to study the damage caused to solid targets by the full impact of the LHC beam as well as the SPS beam. Tungsten, copper and graphite targets have been studied. Experimental an theoretical studies on radiation damage on materials used for the LHC upgrade and the FAIR accelerators are performed at the present GSI experimental facilities. Technical decisions based on these results will have an impact on the FAIR component specifications. A cryogenic ion-catcher prototype will be constructed and tested. The ion-catcher is essential for reaching highest heavy ion beam intensities in SIS100. The prototype will be set-up at GSI to perform measurements with heavy ion beams of synchrotron SIS18.
BNL, Upton, Long Island, New York
Electron lenses for the head-on beam-beam compensation are under construction at the Relativistic Heavy Ion Collider. The bunch length is of the same order as the beta-function at the interaction point, and a proton passing through another proton bunch experiences a substantial phase shift which modifies the beam-beam interaction. We review the effect of the bunch length in the single pass beam-beam interaction, apply the same analysis to a proton passing through a long electron lens, and study the single pass beam-beam compensation with long bunches.