RIKEN Nishina Center, Wako
The RIKEN RI Beam Factory (RIBF) is pushing the limits of energy for heavy ion cyclotrons. The first experiment of the RIBF has successfully finished with the discovery of new isotopes 125Pd and 126Pd* in June 2007 with a 345-MeV/nucleon uranium beam. However, the total transmission efficiency was limited to be less than 1%. In addition, a carry-over of oil was found in the refrigerator of the Superconducting Ring Cyclotron (SRC), which was the main accelerator of the RIBF. To solve these problems, we have improved beam monitors, upgraded the oil remover system of the compressor of the liquid helium cryogenic plant at SRC and made a series of acceleration tests. As a result, 0.3 pnA of a 345-MeV/nucleon uranium beam was stably delivered to RIBF users in November 2008 and a 345-MeV/nucleon 48Ca beam with the intensity of 170 pnA was obtained in December 2008. In the PAC09 presentation, we will summarize our operating experience with the SRC and developments of RIBF accelerators in addition to most up-to-date performance of the RIBF accelerator complex.
*T. Ohnishi et al., J. Phys. Soc. Jpn. 77 (2008) 083201
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire
EMMA, the Electron Model with Many Applications, was originally conceived as a model of a GeV-scale muon accelerator. The non-scaling (NS) properties of resonance crossing, small apertures, parabolic ToF and serpentine acceleration are novel, unproven accelerator physics and require "proof of principle". EMMA has metamorphosed from a simple "demonstration" objective to a sophisticated instrument for accelerator physics investigation with operational demands far in excess of the muon application that lead to technological challenges in magnet design, rf optimisation, injection and extraction, and beam diagnostics. Machine components procured in 2008 will be installed February-May 2009 leading to full system tests June-August and commissioning with electrons beginning September 2009.
ORNL, Oak Ridge, Tennessee
Funding: SNS is managed by UT-Battelle, LLC, for the U.S. DOE under contract DE-AC05-00OR22725
The SNS Ring has now been operating for about 2.5 years, and our march continues to increase the beam power to the design value of 1.4 MW. The Ring is a loss-limited machine, and in general the radioactivation levels are good, but there are some unanticipated hot spots that we are working to relieve. Beam optics functions have been measured using the model independent and orbit response matrix methods, and our results will be compared to the ideal model. High-intensity beam profiles measurements show space-charge effects, and these will be compared to model calculations. We will also discuss the status of equipment upgrades that are now in progress in the high-energy beam transport momentum dump, the injection-dump beam line, and in the ring-to-target beam line.
IMP, Lanzhou
CSR is a new ion cooler-storage-ring system in China IMP, it consists of a main ring (CSRm) and an experimental ring (CSRe). The two existing cyclotrons of the Heavy Ion Research Facility in Lanzhou (HIRFL) are used as its injector system. The heavy ion beams from the cyclotrons are injected first into CSRm for accumulation with e-cooling and acceleration, finally extracted fast to CSRe for internal-target experiments and mass measurements of radioactive ion beams (RIBs), or extracted slowly for external-target experiments or cancer therapy. In 2005 the CSR construction was completed and the commissioning finished in the past three years. It includes stripping injection (STI), electron-cooling with hollow electron beam, C-beam stacking with the combination of STI and e-cooling, wide energy-range acceleration from 7 MeV/u to {10}00 MeV/u with the RF harmonic-number changing, multiple multi-turn injection (MMI) and beam accumulation with MMI and e-cooling for heavy-ion beams of Ar, Kr and Xe, fast and slow extraction from CSRm, the commissioning of CSRe with two lattice modes, and a RIB mass-spectrometer test with the isochronous mode in CSRe by the time-of-flight method.
RRCAT, Indore (M.P.)
Particle accelerator programs being pursued by the Indian labs cover a broad range, encompassing accelerators for nuclear physics research (NPR) (in the low and intermediate energy range), construction of synchrotron radiation sources (SRS) as well as participation in international accelerator projects, especially those related to high energy physics. Machines for NPR include 14MV Pelletrons, augmented by home built superconducting linac boosters to enhance the energy & mass range of the ion beams, and a superconducting cyclotron which is currently undergoing commissioning at Kolkata. Two SRS, namely, a 450 MeV ring Indus-1 and 2.5 GeV booster cum light source, Indus-2, have been indigenously constructed and set up at Indore. A program is also on to develop a high current proton accelerator that will eventually be used for R&D linked to ADS. Regarding our international collaborations, Indian labs have contributed to setting up of LHC at CERN, are associated with the CLIC Test Facility 3 & Linac-4 and the FAIR project at Hamburg besides working with Fermilab on ILC/Project-X R&D. The talk will give an overview of some of the recent developments related to these activities.
CIAE, Beijing
TRIUMF, Vancouver
As a high intensity compact cyclotron, CYCIAE-100 is designed to provide proton beams in two directions simultaneously. At the extraction region, the fringe field of the main and the field of the combination magnet will influence the beam optics. The fringe field may become critical by comparison with the separated sector machine because of the compact structure. The dispersion during the beam extraction should not be ignored, which may make the beam envelop become evidently bigger. Then the beam loss and residual radiation increase. To study the beam optics at the extraction region of CYCIAE-100, the orbit tracking and transfer matrix calculation and symplectic by function extension of the code GOBLIN and modification of STRIPUBC have been implemented. The characteristics of the extracted beam have been investigated based on the main field from a FEM code and overlapping with the field generated from the combination magnet at each extraction port. The results are also compared with those from the CIAE’s code CYCTRS to confirm this precise prediction. The transfer matrix from this simulation is analyzed and used for the down stream beam line design.
CIAE, Beijing
FZJ, Jülich
The 10 mA, 40keV H- pulsed injection line for the CIAE 10 MeV CRM cyclotron has two main operation modes for bunched beams: delivering 5 mA CW beam or chopped pulse with more than 100uA. Chopped pulse is achieved by placing behind the 70.5 MHz bunching cavity a sinusoidal transverse deflecting cavity with frequency of 2.2 MHz, 1/32 of the bunching frequency. Particles outside the wanted ±3° phase width @ 2.2 MHz, corresponding to ±90° @ 70.5 MHz, are either absorbed in a 50cm drift after chopper or at round slit1, 1cm aperture. Time dependence of sinusoidal chopping field causes RMS emittance increase by a factor 3 and changes twiss parameter alpha by a factor 2 before the round slit1. Solenoid couples motion in transversal planes, but equalizes both RMS emittances. Particle tracking results are presented for the chopped pulse, showing longitudinal-transverse coupling in the deflector and equalization of RMS emittances in the solenoid. Optimised focusing strength leads to about 1 % transmission efficiency for the chopped pulse. The CRM inflector receives 2.4 ns long pulse at about 4.4 MHz repetition rate, 1/16 of the RF frequency.
CEA, Gif-sur-Yvette
Sigmaphi, Vannes
Imperial College of Science and Technology, Department of Physics, London
Funding: Agence Nationale de la Recherche, France, contract NT05-1_41853
A prototype of a spiral lattice FFAG magnet has been constructed in the frame of the RACCAM project*. THis magnet is subject to extensive field measurements and 3-dimensional field map measurements. The properties and qualities of the magnet are assessed directly from ray-tracing, using stepwise integration, for deriving lattice parameters as tunes, chromaticities, dynamic paertures, etc. Reporting on this is the subject of the poster.
*http://lpsc.in2p3.fr/service_accelerateurs/raccam.htm
SIGMAPHI S.A., Vannes
CEA, Gif-sur-Yvette
Funding: ANR contract nb : NT05-141853
This paper presents an alternative design of the magnet for the RACCAM project. The aim of this collaboration is to study and build a prototype of a scaling spiral FFAG as a possible medical machine for hadron therapy. The magnet was first designed with a variable gap to produce the desired field law B=B0(r/r0)^k. The key feature in the “scaling” behavior of the magnet is in getting the fringe field extent to be proportional to the radius. Although the fringe field is increasing with gap dimension, we have obtained quit constant tunes in both horizontal and vertical by using a variable chamfer. An alternative magnet design was then proposed with parallel gap and distributed conductors on the pole to create the required field variation. This solution requires about 40 conductors along the pole and much more power than the gap shaping solution. We expect a much better tune constancy even without variable chamfer. We can think about an “hybrid” magnet with parallel gap at small radii and gap shaping afterward. Such a solution could take advantages of both solutions.
ENEA C.R. Frascati, Frascati (Roma)
SPARKLE S.r.l., Casarano (Lecce)
SPARKLE company is setting up in the south of Italy (Casarano) a new cyclotron facility based on a 18 MeV, 150 uA IBA Cyclone 18/9. The aim is to create a multidisciplinary research site for the medical applications of accelerators. The main activity will be the production of standard and new radionuclides, by internal targets and one external beam line. Another opposite beam line has been reserved for low current proton irradiations for radiotherapy studies, and a linac booster between 18 and 24 MeV was designed and built to this end. The beam line, which focuses and matches the beam to the linac, includes a chopping system to synchronize the beam to the pulsed linac and to collect 99% of the beam not synchronous to the linac. The linac uses a 3 GHz SCDTL structure powered by a magnetron modulator system. In the paper we report an overview of the beam line, component design, and tests.
FZJ, Jülich
University of Erlangen-Nürnberg, Physikalisches Institut II, Erlangen
INFN-Ferrara, Ferrara
The PAX Collaboration is planning experiments using polarized Antiprotons. The only experimentally proven method so far which could lead to the production of polarized antiprotons is the spin-filtering. In particular, spin-filtering has been used to generate polarized protons in an experiment at the Heidelberg TSR*. In order to optimize spin-filtering for the production of polarized antiprotons dedicated experiments are planned at COSY with protons and AD (CERN) with antiprotons. The experimentation at COSY has already started in 2007. A decisive experiment has been performed to settle a long controversy about the role of electrons in the polarization buildup by spin-filtering. Instead of studying the polarization buildup in an initially unpolarized beam, the inverse situation was investigated by observation of depolarization of an initially polarized beam. For the first time the electrons of the electron cooler have been used as a target to study their depolarizing effects on the stored beam. At the same time a series of machine experiments have been performed to study the beam lifetime at different energies.
*F. Rathmann et al., Phys. Rev. Lett. 71, 1993, p.1379
JINR, Dubna, Moscow Region
The current status of the JINR FLNR cyclotrons and plans of their modernization are reported. At present time, four isochronous cyclotrons: U400, U400M, U200 and IC100 are under operation at the JINR FLNR. The U400 and the U400M are the basic cyclotrons that are under operation about 6000 and 3000 hours per year correspondingly. Both the accelerators are used in DRIBS experiments to produce and accelerate exotic very neutron-rich isotopes of light elements such as 6He and 8He. The U400 (pole diameter of D=4 m) is designed to accelerate ion beams of atomic masses from 4 to 209 to maximum energy of 26 MeV/u for synthesis of the new super heavy elements and other physical experiments. The U400M cyclotron (D=4 m) is used to accelerate ions of elements from Li to Ar up to 50 MeV/u and heavier ions such as 48Ca, Kr,Xe, up to 6 MeV/u after recent modernization. The U200 cyclotron (D=2 m) is used to produce isotopes by using He ions with energies about 9 MeV/u, modernization of the cyclotron injection is planned. Modernized IC100 accelerator (D=1m) is used to produce track membranes and carrying out experiments in solid-state physics by using Ar, Kr and Xe ions at energies of 1.2 MeV/u.
JINR, Dubna, Moscow Region
In axial injection channels of FLNR JINR cyclotrons the axial symmetric ion beam is formed just after the analyzing bending magnet. This gives an opportunity to use for beam focusing at vertical part of the channel solenoidal magnetic lenses only. During the motion of intense axial symmetric beam in the longitudinal magnetic field of solenoids and cyclotron the transverse tunes Qx, Qy coincide. In this case the small disturbance of beam axial symmetry leads to excitation of coupling resonance Qx-Qy=0 due to beam self-fields. The influence of the resonance results in significant asymmetry of the transverse beam emittances. The magnitude of this asymmetry is evaluated within the framework of moments method and is in a good agreement with one obtained in the macro-particles simulation. The correction of resonance by means of the normal quadrupole lens is proposed.
JINR, Dubna, Moscow Region
IBA, Louvain-la-Neuve
C400 is compact superconducting cyclotron for hadron therapy. The permissible level of the transverse magnetic field at the horizontal part of axial injection beam line of a cyclotron is about 10 Gauss. At the same time the C400 magnetic field is about 500 Gauss in magnitude at the places of the ion sources, vertical bending magnet and quadrupole lens location. Thereby the screening of these beam-line elements is needed. The 3D OPERA model of the cyclotron and channel elements is used for this purpose.
JINR, Dubna, Moscow Region
IBA, Louvain-la-Neuve
C400 is compact superconducting isochronous cyclotron for carbon beam therapy designed by IBA, Louvain-La-Neuve (Belgium) in collaboration with JINR, Dubna (Russia). The cyclotron can accelerate all ions with charge to mass ratio 0.5. Protons are accelerated as single charge 2H+ molecules and extracted by stripping at 270 MeV. All other ions are extracted by an electrostatic deflector at 400 MeV/u. The final layout of the axial injection beam line of C400 cyclotron is given. Two ion sources for production of 12C6+ ions and Alphas beams are located at the horizontal part of the channel before both side of the combination vertical magnet. The third ion source for the production of 2H+ is placed in straight line on the vertical axis. The rotational symmetry of the beam is reestablished with the help of one quadrupole lens placed just after analyzing magnet. The beam focusing at the vertical part of the channel is provided by three solenoidal lenses instead of four quadrupoles used in the previous version of beam line. The results of simulation of ion beams transport in the axial injection channel are presented.
Cockcroft Institute, Warrington, Cheshire
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire
EMMA (Electron Machine with Many Applications) is a prototype non-scaling electron FFAG currently under construction at Daresbury Laboratory. The energy recovery linac prototype ALICE will operate as its injector, at a reduced the energy of 10 to 20 MeV, compared to its nominal energy of 35 MeV. An injection line has been designed which consists of a dogleg to extract the beam from ALICE, a matching section, a tomography section and some additional dipoles and quadrupoles to transport and match the beam to the entrance of EMMA. This injection line serves both as a diagnostic to measure the properties of the beam being injected into EMMA and also a useful diagnostic tool for ALICE operation. This paper details the simulations undertaken of the electron beam passing through the matching and tomography sections of the EMMA injection line, including the effect of space charge. This will be an issue in the energy range at which this diagnostic is being operated when combined with high bunch charge. A number of different scenarios have been modelled and an attempt made to compensate for the effects of space charge in the matching and tomography sections.
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire
EMMA (Electron Machine with Many Applications) is a prototype non-scaling electron FFAG to be hosted at Daresbury Laboratory. NS-FFAGs related to EMMA have an unprecedented potential for medical accelerators for carbon and proton hadron therapy. It also represents a possible active element for an ADSR (Accelerator Driven Sub-critical Reactor). This paper will summarize the design of the extraction / diagnostic transfer line of the NS-FFAG. In order to operate EMMA, the energy recovery linac ALICE shall be used as injector and the energy will range from 10 to 20 MeV. Because this would be the first non-scaling FFAG, it is important that as many of the bunch properties are studied as feasible, both at injection and at extraction. To do this, a complete diagnostic line was designed consisting of a tomography module together with several other diagnostic devices including the possibility of using a transverse deflecting cavity. Details of the diagnostics are also presented.
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire
BNL, Upton, Long Island, New York
Fermilab, Batavia
TRIUMF, Vancouver
EMMA (Electron Machine with Many Applications) is a prototype non-scaling electron FFAG to be hosted at Daresbury Laboratory. NS-FFAGs related to EMMA have an unprecedented potential for medical accelerators for carbon and proton hadron therapy. It also represents a possible active element for an ADSR (Accelerator Driven Sub-critical Reactor). This paper summarises the commissioning plans for this machine together with the major steps and experiments involved along the way. A description of how the 10 to 20 MeV beam is achieved within ALICE is also given, as well as extraction from the EMMA ring to the diagnostics line and then dump.
Sigmaphi, Vannes
CEA, Gif-sur-Yvette
LPSC, Grenoble
The paper presents the magnetic measurements of the RACCAM prototype FFAG dipole, manufactured by SIGMAPHI for the Raccam ANR Medical FFAG project. This magnet prototyping work, started early 2006, is being performed in collaboration between the IN2P3/LPSC Laboratory team and SIGMAPHI. This paper describes the magnetic measurement results and comparison with Tosca simulation.
CIAE, Beijing
TRIUMF, Vancouver
Department of Physics, Central China Normal University, Wuhan
There is increasing interest in high current compact H- cyclotrons for RIB, isotope production or as injectors for sub-critical reactor testing facilities. For compact cyclotrons, a practical limit on the output energy, to prevent significant Lorentz stripping and resulting activation, is ~100 MeV. Vacuum dissociation is another critical problem, because a compact structure and small parts inside the tank make high vacuum challenging. This paper describes how Lorentz stripping and vacuum dissociation were calculated for our “CYCIAE-100” under construction. In order to take into account non uniform magnetic fields and vacuum, losses were calculated by numerically integrating loss equations along tracked orbits, as these were being calculated by the beam dynamics code. To verify the code, losses derived with field and vacuum data from the TRIUMF 500 MeV cyclotron were compared with measurements. For the CYCIAE-100 cyclotron we predict that electromagnetic losses will account for less then 0.3% of total beam, vacuum losses for less than 0.58%, with peak magnetic fields up to 1.35T and average vacuum up to 5·10-8 Torr.
TRIUMF, Vancouver
Fixed-Field Alternating-Gradient (FFAG) accelerators span a large range of momenta and have markedly different reference orbits for each momemtum. In the non-scaling (NS) versions proposed for rapid acceleration, the orbits are geometrically dissimilar. In particular, none of the orbits within bending magnets are arcs of circles and this complicates tune calculation. One approach to NS-FFAG design is to employ alternating combined-function magnets. Second generation NS-FFAGs designs attempt to mitigate the variation of betatron tunes; and careful calculation of orbits and tunes is essential. Starting from an analytic magnetic potential for the combined-function magnet, we elucidate expressions for orbit calculation which are second order in the cyclotron motion and arbitrary order in the momentum (no expansion is used).
UBC & TRIUMF, Vancouver, British Columbia
It is sometimes asserted that Thomas's proposal to provide additional axial focusing in cyclotrons (to enable them to operate isochronously at relativistic energies) by introducing an azimuthal variation in the magnetic field was an early example of alternating-gradient focusing. While Thomas cyclotrons certainly exhibit alternating field gradients, it is shown that the alternating focusing produced is very much weaker than the edge focusing (everywhere positive) arising from orbit scalloping.
UBC & TRIUMF, Vancouver, British Columbia
TRIUMF, Vancouver
This paper describes tracking studies of FFAGs and radial-sector cyclotrons with reverse bends using the cyclotron equilibrium orbit code CYCLOPS. The results for FFAGs confirm those obtained with lumped-element codes, and suggest that cyclotron codes will prove to be important tools for evaluating the measured fields of FFAG magnets. The results for radial-sector cyclotrons show that the use of negative valley fields would allow axial focusing to be maintained, and hence allow intense cw beams to be accelerated, to energies of the order of 10 GeV.
University of Fukui, Faculty of Engineering, Fukui
KURRI, Osaka
FFAG DDS Research Organization, Tokyo
The accelerator–based neutron source using ERIT (Energy/emittance Recovery Internal Target) scheme has been constructed at KURRI (Kyoto University Research Reactor Institute). And the first beam test was successfully completed in March 2008. In this poster, recent status of beam studies will be presented.