CYCLOTRONS 2010 - List of Keywords (acceleration)

Paper	Title	Other Keywords	Page
MOM2CIO02	Intense Beam Operation at GANIL	ion, target, cyclotron, ion-source	16
	F. Chautard GANIL, Caen, France
	The GANIL (Grand Accélérateur National d'Ions Lourds) produces and accelerates stable ions beams since 1982. The first radioactive beam post-accelerated with the CIME cyclotron happened in 2001. In 2013, stable beams with higher intensities and new energy range will be available from the new superconducting linear accelerator SPIRAL2. In 2015, new exotic beams will be accelerated with the existing cyclotron CIME. This paper will show how GANIL manages the SPIRAL2 machine arrival by continuing the delivery of high intensity and exotic beams. But also by pursuing the developments of the machine capabilities in a project structure in order to keep equipments running with a high reliability yield and still responding to physics demands. The progress in ion source production will be exposed. Finally, it will be presented the foreseen calendar of the exploitation for the existing machine together with SPIRAL2.
	Slides MOM2CIO02 [2.928 MB]

MOM2CCO03	Progress towards High Intensity Heavy Ion Beams at the AGOR-Facility	beam-losses, ion, vacuum, cyclotron	21
	S. Brandenburg, J.P.M. Beijers, M.A. Hevinga, M.A. Hofstee, H.R. Kremers, V. Mironov, J. Mulder, S. Saminathan, A. Sen KVI, Groningen, The Netherlands
	Funding: This work is supported by the European Union through EURONS, contract 506065 and the "Stichting voor Fundamenteel Onderzoek der Materie" (FOM). The on-going upgrade program of the AGOR-facility aiming at intensities beyond 10¹² pps for heavy ion beams up to Pb will be discussed. The progress in the main elements of the program (further development of the ECR-source; improvement of the transmission into and through the cyclotron and protection of equipment agains excessive beam loss) will be reported. Further improvement of the ECR ion source is facilitated by the installation of a second source. Redesign of the LEBT to compensate aberrations is in progress; simulations predict a significant increase in transmission. A new, cooled electrostatic extractor is being commissioned and the beam loss control system has been completed. The main remaining issue is vacuum degradation induced by beam loss caused by charge exchange on the residual gas. Experiments at GSI[1] have shown that scrapers and surface coatings can strongly reduce this effect. Tracking calculations of the distribution of the beam losses over the vacuum chamber to determine the optimum location of scrapers and application of a gold coating to relevant parts of the vacuum chamber are underway. [1] C. Omet, H. Kollmus, H. Reich-Sprenger, P. Spiller; Ion catcher system for the stabilisation of the dynamic pressure in SIS18; http://jacow.org/e08/papers/mopc099.pdf
	Slides MOM2CCO03 [1.532 MB]

MOPCP019	Present Status of JAEA AVF Cyclotron Facility	ion, cyclotron, ion-source, target	87
	T. Yuyama, I. Ishibori, T. Ishizaka, H. Kashiwagi, S. Kurashima, N. Miyawaki, T. Nara, S. Okumura, W. Yokota, K. Yoshida, Y. Yuri JAEA/TARRI, Gunma-ken, Japan
	The JAEA AVF cyclotron provides various ion beams mainly for research in materials science and biotechnology such as estimation of radiation hardness of space-use devices, and plant breeding by ion beams. We have been developing ion sources, the cyclotron, and beam irradiation techniques to meet requirements from users. In order to stabilize the beam intensity, power supplies for magnets were improved by installing a digital-to-analog converter (DAC) unit with a Peltier device for coil current control. As a result, coil current stability of main magnet of ± 5 × 10^-6 has been obtained by the renewed DAC unit which guarantees temperature control within 1°C at 30°C. Initially, it took about eight hours to form a heavy-ion microbeam, so it was impractical to change the microbeam ion species in an experiment. However, the microbeam of a 520 MeV 40Ar¹⁴⁺ has been successfully changed to the one of a 260 MeV ²⁰Ne⁷⁺ within 30 minutes using a cocktail beam acceleration technique. A beam profile uniformization system using multipole magnets are being developed to enable uniform irradiation of a large sample at a constant particle fluence rate.

MOPCP041	Beam Tuning in Kolkata Superconducting Cyclotron	cyclotron, ion, extraction, injection	132
	M.K. Dey, R.K. Bhandari, U. Bhunia, J. Debnath, A. Dutta, C. Mallik, Z.A. Naser, S. Paul, J. Pradhan, M.H. Rashid DAE/VECC, Calcutta, India
	The Superconducting cyclotron at VECC, Kolkata, has accelerated ion beams up to extraction radius successfully confirmed by the neutrons produced by the nuclear reactions. The internal beam tuning process started with beam parameters calculated using the measured magnetic field data. Due to some mechanical and electrical problems we were forced to tune the beam with three major trim coils off. Accurate positioning of central region Dee-extensions ensuring the proper acceleration gaps in the first turn was required for successful acceleration of beam through the compact central region clearing the posts in the median plane. Here we present different aspects and results of initial beam tuning.

MOPCP043	Modification of the Central Region in the RIKEN AVF Cyclotron for Acceleration at the H=1 RF Harmonic	proton, cyclotron, ion, emittance	138
	S.B. Vorozhtsov JINR, Dubna, Moscow Region, Russia A. Goto RIKEN Nishina Center, Wako, Japan V.L. Smirnov JINR/DLNP, Dubna, Moscow region, Russia
	Funding: JINR/DLNP, Dubna, Russia, and RIKEN, Wako, Japan A highly advanced upgrade plan of the RIKEN AVF cyclotron is under way. The study is focused on the formulation of the new acceleration regimes in the AVF cyclotron by detailed orbit simulations. The extension of the acceleration energy region of light ions towards higher energies in the existing RF harmonic equal to 2 and the modification of the central geometry for the RF harmonic equal to 1 to allow an acceleration of protons at several tens of MeV are considered. The substantial redesign of the central electrode structure is needed to accelerate protons with reasonable values of the dee voltage. The new inflector geometry and the optimized central electrode structure have been formulated for the upgrade.

MOPCP061	RF Cavity Simulations for Superconducting C400 Cyclotron	simulation, cyclotron, ion, extraction	171
	G.A. Karamysheva, A.A. Glazov, S. Gurskiy, N.A. Morozov JINR, Dubna, Moscow Region, Russia M. Abs, Y. Jongen, W.J.G.M. Kleeven, S. Zaremba IBA, Louvain-la-Neuve, Belgium O. Karamyshev JINR/DLNP, Dubna, Moscow region, Russia
	Compact superconducting isochronous cyclotron C400 has designed at IBA (Belgium) in collaboration with the JINR (Dubna). This cyclotron will be the first cyclotron in the world capable of delivering protons, carbon and helium ions for therapeutic use. ¹²C⁶⁺ and ⁴He²⁺ ions will be accelerated to 400 MeV/u energy and extracted by electrostatic deflector, H²⁺ ions will be accelerated to the energy 265 MeV/u and extracted by stripping. It is planed to use two normal conducting RF cavities for ion beam acceleration in cyclotron C400. Computer model of the double gap delta RF cavity with 4 stems was developed in is a general-purpose simulation software CST STUDIO SUITE. Necessary resonant frequency and increase of the voltage along the gaps were achieved. Optimization of the RF cavity parameters leads us to the cavity with quality factor about 14000, RF power dissipation is equal to about 50 kW per cavity.

MOPCP090	Progress in Formation of Single-Pulse Beams by a Chopping System at the JAEA/TIARA facility	cyclotron, extraction, ion, controls	233
	S. Kurashima, I. Ishibori, T. Nara, W. Yokota JAEA/TARRI, Gunma-ken, Japan M. Taguchi JAEA/QuBS, Takasaki, Japan
	The intervals of beam pulses from a cyclotron is generally tens of ns and they are too short for pulse radiolysis experiments which require beam pulses at intervals ranging from 1 μs to 1 ms (single-pulse beam). A chopping system, consisting of two types of high voltage kickers, is used at the JAEA AVF cyclotron to form single-pulse beam. The first kicker installed in the injection line generates beam pulses with repetition period of 1 μs to 1 ms. The pulse width is about a cycle length of the acceleration frequency. The other kicker in the transport line thins out needless beam pulses caused by multi-turn extraction. We could not provide single-pulse beam stably over 30 min since the magnetic field of the cyclotron gradually decreased by 0.01 % and the number of multi-turn extraction increased. The magnetic field was stabilized within 0.001 % by keeping temperature of the cyclotron magnet constant. In addition, a new technique to measure and control an acceleration phase has enabled us to reduce the number of multi-turn extraction easier than before. We have succeeded to provide single-pulse beam of a 320 MeV carbon without retuning of the cyclotron over 4 h, as a result.

MOPCP094	Consistency in Measurement of Beam Phase and Beam Intensity Using Lock-in Amplifier and Oscilloscope Systems	cyclotron, monitoring, beam-transport, rfq	245
	R. Koyama, M. Fujimaki, N. Fukunishi, A. Goto, M. Hemmi, O. Kamigaito, M. Kase, N. Sakamoto, K. Suda, T. Watanabe, K. Yamada RIKEN Nishina Center, Wako, Japan
	The RIKEN RI beam factory (RIBF) consists of four ring cyclotrons (RRC, fRC, IRC, and SRC) and two injectors (RILAC and AVF) which are all connected in cascade. RILAC, AVF, and RRC began operation in the 1980s, and fRC, IRC, and SRC were installed in 2006. Phase probes (PPs) are installed in all cyclotrons and beam transport lines of RIBF, and the beam-bunch signals that are detected nondestructively by these PPs are used for tuning of isochronous magnetic field of cyclotrons and for monitoring the beam phase and beam intensity. We mainly use a newly developed system that incorporates a lock-in amplifier (LIA; SR844, SRS) for those tuning and monitoring; however, in AVF and RRC, a conventional measurement method using an oscilloscope system (OSC; DSO6052A, Agilent) is used. In this study, we investigated the consistency in the measurements carried out using LIA and OSC systems by Fourier analyzing the observed data. Additionally, we investigated the resolution and measurement uncertainty of LIA and OSC.

MOPCP098	Influence of RF Magnetic Field on Ion Dynamics in IBA C400 Cyclotron	cyclotron, ion, radio-frequency, resonance	251
	E. Samsonov, G.A. Karamysheva, S.A. Kostromin JINR, Dubna, Moscow Region, Russia Y. Jongen IBA, Louvain-la-Neuve, Belgium
	Magnetic components of RF field in C400 cyclotron being under development by IBA makes noticeable influence on ion dynamics. In particular, increase in the dees voltage along radius leads to corresponding phase compression of a bunch. Influence of the RF magnetic field on the bunch center phase deviation during acceleration and on radial ion axial motions have been also estimated numerically. RF magnetic field changes a central ion phase by only 2° RF. Calculations have also shown that RF magnetic field makes visible but pretty small influence on the radial motion of the ions ensuring some decrease in the radial amplitudes. No visible impact of the RF magnetic field on the axial motion has been detected. The results are compared for the two RF magnetic field maps: (i) obtained by Microwave Studio and, (ii) computed from RF electric field map by means of Maxwell' equations.

TUM2CIO01	Status of RIBF Accelerators at RIKEN	cyclotron, ion, ion-source, rfq	286
	O. Kamigaito, S. Arai, T. Dantsuka, M. Fujimaki, T. Fujinawa, H. Fujisawa, N. Fukunishi, A. Goto, H. Hasebe, Y. Higurashi, K. Ikegami, E. Ikezawa, H. Imao, T. Kageyama, M. Kase, M. Kidera, M. Komiyama, H. Kuboki, K. Kumagai, T. Maie, M. Nagase, T. Nakagawa, M. Nakamura, J. Ohnishi, H. Okuno, N. Sakamoto, K. Suda, H. Watanabe, T. Watanabe, Y. Watanabe, K. Yamada, Y. Yano, S. Yokouchi RIKEN Nishina Center, Wako, Japan
	Recent developments and upgrade program in the near future at RIKEN RI-Beam Factory (RIBF) are presented. The beam intensity and available ion species are increasing at RIBF, owing to the continuous efforts that have been paid since the first beam in 2006. So far, we accelerated deuteron, helium, nitrogen, oxygen, aluminum, calcium, krypton, and uranium beams with the superconducting ring cyclotron, SRC. The extracted beam intensities reached 1,000 pnA for helium and oxygen beams. From the operational point of view, however, the intensity of the uranium beam should be much increased. We are, therefore, constructing a new injector linac for the RIBF, consisting of a superconducting ECR ion source, RFQ, and DTL, which will be commissioned in this fiscal year. By using this injector, we also aim at independent operation of the RIBF and GARIS facility for super-heavy element synthesis.
	Slides TUM2CIO01 [4.914 MB]

TUA2CCO02	Induction Sector Cyclotron for Cluster Ions	ion, induction, cyclotron, focusing	314
	K. Takayama, T. Adachi KEK, Ibaraki, Japan W. Jiang Nagaoka University of Technology, Nagaoka, Niigata, Japan Y. Oguri TIT, Tokyo, Japan H. Tsutsui SHI, Tokyo, Japan
	Funding: supported by Grant-in-Aid for Exploratory Research (KAKENHI 22265403) A novel scheme of a sector cyclotron to accelerate extremely heavy cluster ions, called 'Induction Sector Cyclotron (ISC)', is described [1]. Its key feature is fast induction acceleration, which has been already demonstrated using the KEK 12 GeV proton synchrotron [2]. An ion bunch is accelerated and captured with pulse voltages generated by transformers. The acceleration and confinement in the longitudinal direction can be independently handled. The transformers are energized by the corresponding switching power supply, in which power solid-state devices are employed as switching elements and their turning on/off is maneuvered by gate signals digitally manipulated from the circulating beam signal of an ion bunch. Consequently the acceleration synchronizing with the revolution of any ion beam is always guaranteed. A cluster ion beam such as C-60, which so far there has been no way to repeatedly accelerate, can be accelerated from an extremely low velocity to a nearly light velocity. Its fundamental concept, beam dynamics, required key devices, and life time of a cluster ion beam will be discussed. A typical example of ISC is proposed at the conference. [1] K.Takayama et al., submitted to Phys. Rev. Lett. (2010). [2] K.Takayama et al., Phys. Rev. Lett. 98, 054801 (2007), K.Takayama and R.Briggs (Eds.), 'Induction Accelerators' (Springer, 2010).
	Slides TUA2CCO02 [1.781 MB]

WEM2CCO02	Operating Experience with the RF System for Superconducting Ring Cyclotron of RIBF	cyclotron, vacuum, cryogenics, pick-up	338
	N. Sakamoto, M. Fujimaki, A. Goto, O. Kamigaito, M. Kase, R. Koyama, K. Suda, K. Yamada, S. Yokouchi RIKEN Nishina Center, Wako, Japan
	Since December 2006, Superconducting Ring Cyclotron (SRC) has been operational. Up to now, the beams of ²³⁸U, ⁴⁸Ca, pol-d, N, ⁴He have been provided for nuclear physics experiments. The SRC consists of 6 superconducting sector magnets, 4 accelerating cavities and one flattop cavity. Designed value of the acceleration voltage is 2 MV/turn. The gap voltage of 600 kV is excited with 130 kW rf power in the accelerating cavity. The cavities have been installed at four valley regions of 6 sector magnets and are exposed to a strong stray field of superconducting magnets. The strength of the magnetic field is as large as a few kilogauss. It is found that the condition of multipactor depends drastically on the strength of the stray field. How to treat the multipactor is one of the most important issues for stable operation of the SRC. This paper will discuss on our efforts to settle the problem concerning the cavities. By improving the vacuum, cooling, surface treatment and so on, we finally succeeded to minimize the break time due to the rf break down of the SRC cavities during experiments.
	Slides WEM2CCO02 [9.291 MB]

THM1CIO01	Post-acceleration of High Intensity RIB through the CIME Cyclotron in the Frame of the SPIRAL2 Project at GANIL	cyclotron, ion, linac, ion-source	354
	P. Bertrand, A. Savalle GANIL, Caen, France
	The cyclotron CIME is presently used at GANIL for the acceleration of SPIRAL1 radioactive beams. One of the goals of the SPIRAL2 project is to produce, post-accelerate and use in the existing experimental areas much higher intensity secondary beams induced by uranium fission like neutron-rich krypton, xenon, tin isotopes, and many others. Intensity may reach 10¹⁰ pps. Specific developments are needed for secondary beam diagnostics. Improvement of mass separation is also necessary, and the Vertical Mass Separator (VMS) is specially developed for this purpose. However, the main concern is related to the high radioactivity linked to RIB high intensity. Safety and radioprotection issues will require modifications of the installation with special care for the maintenance of the cyclotron. The experience of the SPIRAL1 beams, in terms of beam losses and equipment contamination, is especially useful to define the necessary modifications.
	Slides THM1CIO01 [6.133 MB]

THM1CIO02	Acceleration above the Coulomb Barrier - Completion of the ISAC-II Project at TRIUMF	linac, ion, vacuum, cyclotron	359
	R.E. Laxdal TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada
	The ISAC-II project at TRIUMF was proposed to boost the final energy of the radioactive ion beams of the TRIUMF ISAC facility above the Coulomb barrier. The nominal goal of 6.5 MeV/u for ions with A/q=6 was recently achieved. The ISAC-II post-accelerator consists of 40 MV of installed heavy ion superconducting linac to broaden the energy reach and a charge state booster to broaden the mass reach. Details of the project and the ISAC-II commissioning and operation will be presented.
	Slides THM1CIO02 [3.619 MB]

THA1CIO01	FFAG Developments in Japan	proton, optics, lattice, betatron	376
	Y. Mori KURRI, Osaka, Japan
	Recent activities of the research and development works on FFAG accelerators in Japan are reviewed in this talk.
	Slides THA1CIO01 [27.606 MB]

THA1CIO02	First Commissioning Results from the Non-Scaling FFAG Accelerator, EMMA	septum, controls, injection, lattice	384
	S.L. Smith STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
	The first results from commissioning EMMA - the Electron Model of Many Applications- are summarised in this paper. EMMA is a 10 to 20 MeV electron ring designed to test our understanding of beam dynamics in a relativistic linear non-scaling fixed field alternating gradient accelerator (FFAG). EMMA will be the world's first non-scaling FFAG and the paper will outline the characteristics of the beam injected in to the accelerator as well as summarising the results of the 4 sector 'gantry-type' commissioning which took place at Daresbury Laboratory. The paper will report on recent progress made with the full EMMA ring commissioning, giving details of tune and orbit measurements as well as their correction to the desired lattice.
	Slides THA1CIO02 [5.404 MB]

THA1CIO03	Innovations in Fixed-Field Accelerators: Design and Simulation	focusing, cyclotron, synchrotron, controls	389
	C. Johnstone Fermilab, Batavia, USA M. Berz, K. Makino MSU, East Lansing, Michigan, USA S.R. Koscielniak TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada P. Snopok UCR, Riverside, California, USA
	The drive for high beam power, high duty cycle, and reliable beams has focused world interest on fixed field accelerators, notably Fixed-field Alternating Gradient accelerators (FFAGs) ' with cyclotrons representing a specific class of fixed-field accelerators. Recently, the concept of isochronous orbits has been developed for nonscaling FFAGs using new methodologies in FFAG design. The property of isochronous orbits enables the simplicity of fixed RF and, by tailoring a nonlinear radial field profile, the FFAG is isochronous well into the relativistic regime. The machine proposed here has the high current advantage and duty cycle of the cyclotron in combination with the strong focusing, smaller losses, and energy variability that are more typical of the synchrotron. Further, compact high-performance devices are often are operated in a regime where space charge effects become significant, but are complicated to analyze in fixed-field accelerators because of the cross talk between beams at different nearby radii. A new space charge simulation approach is under development in the code COSY INFINITY. This presentation reports on advances in FFAG accelerator design and simulation.
	Slides THA1CIO03 [1.527 MB]

Paper

Title

Other Keywords

Page

MOM2CIO02

Intense Beam Operation at GANIL

ion, target, cyclotron, ion-source

16

F. Chautard
GANIL, Caen, France

The GANIL (Grand Accélérateur National d'Ions Lourds) produces and accelerates stable ions beams since 1982. The first radioactive beam post-accelerated with the CIME cyclotron happened in 2001. In 2013, stable beams with higher intensities and new energy range will be available from the new superconducting linear accelerator SPIRAL2. In 2015, new exotic beams will be accelerated with the existing cyclotron CIME. This paper will show how GANIL manages the SPIRAL2 machine arrival by continuing the delivery of high intensity and exotic beams. But also by pursuing the developments of the machine capabilities in a project structure in order to keep equipments running with a high reliability yield and still responding to physics demands. The progress in ion source production will be exposed. Finally, it will be presented the foreseen calendar of the exploitation for the existing machine together with SPIRAL2.

Slides MOM2CIO02 [2.928 MB]

MOM2CCO03

Progress towards High Intensity Heavy Ion Beams at the AGOR-Facility

beam-losses, ion, vacuum, cyclotron

21

S. Brandenburg, J.P.M. Beijers, M.A. Hevinga, M.A. Hofstee, H.R. Kremers, V. Mironov, J. Mulder, S. Saminathan, A. Sen
KVI, Groningen, The Netherlands

Funding: This work is supported by the European Union through EURONS, contract 506065 and the "Stichting voor Fundamenteel Onderzoek der Materie" (FOM).
The on-going upgrade program of the AGOR-facility aiming at intensities beyond 10¹² pps for heavy ion beams up to Pb will be discussed. The progress in the main elements of the program (further development of the ECR-source; improvement of the transmission into and through the cyclotron and protection of equipment agains excessive beam loss) will be reported. Further improvement of the ECR ion source is facilitated by the installation of a second source. Redesign of the LEBT to compensate aberrations is in progress; simulations predict a significant increase in transmission. A new, cooled electrostatic extractor is being commissioned and the beam loss control system has been completed. The main remaining issue is vacuum degradation induced by beam loss caused by charge exchange on the residual gas. Experiments at GSI[1] have shown that scrapers and surface coatings can strongly reduce this effect. Tracking calculations of the distribution of the beam losses over the vacuum chamber to determine the optimum location of scrapers and application of a gold coating to relevant parts of the vacuum chamber are underway.
[1] C. Omet, H. Kollmus, H. Reich-Sprenger, P. Spiller; Ion catcher system for the stabilisation of the dynamic pressure in SIS18; http://jacow.org/e08/papers/mopc099.pdf

Slides MOM2CCO03 [1.532 MB]

MOPCP019

Present Status of JAEA AVF Cyclotron Facility

ion, cyclotron, ion-source, target

87

T. Yuyama, I. Ishibori, T. Ishizaka, H. Kashiwagi, S. Kurashima, N. Miyawaki, T. Nara, S. Okumura, W. Yokota, K. Yoshida, Y. Yuri
JAEA/TARRI, Gunma-ken, Japan

The JAEA AVF cyclotron provides various ion beams mainly for research in materials science and biotechnology such as estimation of radiation hardness of space-use devices, and plant breeding by ion beams. We have been developing ion sources, the cyclotron, and beam irradiation techniques to meet requirements from users. In order to stabilize the beam intensity, power supplies for magnets were improved by installing a digital-to-analog converter (DAC) unit with a Peltier device for coil current control. As a result, coil current stability of main magnet of ± 5 × 10^-6 has been obtained by the renewed DAC unit which guarantees temperature control within 1°C at 30°C. Initially, it took about eight hours to form a heavy-ion microbeam, so it was impractical to change the microbeam ion species in an experiment. However, the microbeam of a 520 MeV 40Ar¹⁴⁺ has been successfully changed to the one of a 260 MeV ²⁰Ne⁷⁺ within 30 minutes using a cocktail beam acceleration technique. A beam profile uniformization system using multipole magnets are being developed to enable uniform irradiation of a large sample at a constant particle fluence rate.

MOPCP041

Beam Tuning in Kolkata Superconducting Cyclotron

cyclotron, ion, extraction, injection

132

M.K. Dey, R.K. Bhandari, U. Bhunia, J. Debnath, A. Dutta, C. Mallik, Z.A. Naser, S. Paul, J. Pradhan, M.H. Rashid
DAE/VECC, Calcutta, India

The Superconducting cyclotron at VECC, Kolkata, has accelerated ion beams up to extraction radius successfully confirmed by the neutrons produced by the nuclear reactions. The internal beam tuning process started with beam parameters calculated using the measured magnetic field data. Due to some mechanical and electrical problems we were forced to tune the beam with three major trim coils off. Accurate positioning of central region Dee-extensions ensuring the proper acceleration gaps in the first turn was required for successful acceleration of beam through the compact central region clearing the posts in the median plane. Here we present different aspects and results of initial beam tuning.

MOPCP043

Modification of the Central Region in the RIKEN AVF Cyclotron for Acceleration at the H=1 RF Harmonic

proton, cyclotron, ion, emittance

138

S.B. Vorozhtsov
JINR, Dubna, Moscow Region, Russia
A. Goto
RIKEN Nishina Center, Wako, Japan
V.L. Smirnov
JINR/DLNP, Dubna, Moscow region, Russia

Funding: JINR/DLNP, Dubna, Russia, and RIKEN, Wako, Japan
A highly advanced upgrade plan of the RIKEN AVF cyclotron is under way. The study is focused on the formulation of the new acceleration regimes in the AVF cyclotron by detailed orbit simulations. The extension of the acceleration energy region of light ions towards higher energies in the existing RF harmonic equal to 2 and the modification of the central geometry for the RF harmonic equal to 1 to allow an acceleration of protons at several tens of MeV are considered. The substantial redesign of the central electrode structure is needed to accelerate protons with reasonable values of the dee voltage. The new inflector geometry and the optimized central electrode structure have been formulated for the upgrade.

MOPCP061

RF Cavity Simulations for Superconducting C400 Cyclotron

simulation, cyclotron, ion, extraction

171

G.A. Karamysheva, A.A. Glazov, S. Gurskiy, N.A. Morozov
JINR, Dubna, Moscow Region, Russia
M. Abs, Y. Jongen, W.J.G.M. Kleeven, S. Zaremba
IBA, Louvain-la-Neuve, Belgium
O. Karamyshev
JINR/DLNP, Dubna, Moscow region, Russia

Compact superconducting isochronous cyclotron C400 has designed at IBA (Belgium) in collaboration with the JINR (Dubna). This cyclotron will be the first cyclotron in the world capable of delivering protons, carbon and helium ions for therapeutic use. ¹²C⁶⁺ and ⁴He²⁺ ions will be accelerated to 400 MeV/u energy and extracted by electrostatic deflector, H²⁺ ions will be accelerated to the energy 265 MeV/u and extracted by stripping. It is planed to use two normal conducting RF cavities for ion beam acceleration in cyclotron C400. Computer model of the double gap delta RF cavity with 4 stems was developed in is a general-purpose simulation software CST STUDIO SUITE. Necessary resonant frequency and increase of the voltage along the gaps were achieved. Optimization of the RF cavity parameters leads us to the cavity with quality factor about 14000, RF power dissipation is equal to about 50 kW per cavity.

MOPCP090

Progress in Formation of Single-Pulse Beams by a Chopping System at the JAEA/TIARA facility

cyclotron, extraction, ion, controls

233

S. Kurashima, I. Ishibori, T. Nara, W. Yokota
JAEA/TARRI, Gunma-ken, Japan
M. Taguchi
JAEA/QuBS, Takasaki, Japan

The intervals of beam pulses from a cyclotron is generally tens of ns and they are too short for pulse radiolysis experiments which require beam pulses at intervals ranging from 1 μs to 1 ms (single-pulse beam). A chopping system, consisting of two types of high voltage kickers, is used at the JAEA AVF cyclotron to form single-pulse beam. The first kicker installed in the injection line generates beam pulses with repetition period of 1 μs to 1 ms. The pulse width is about a cycle length of the acceleration frequency. The other kicker in the transport line thins out needless beam pulses caused by multi-turn extraction. We could not provide single-pulse beam stably over 30 min since the magnetic field of the cyclotron gradually decreased by 0.01 % and the number of multi-turn extraction increased. The magnetic field was stabilized within 0.001 % by keeping temperature of the cyclotron magnet constant. In addition, a new technique to measure and control an acceleration phase has enabled us to reduce the number of multi-turn extraction easier than before. We have succeeded to provide single-pulse beam of a 320 MeV carbon without retuning of the cyclotron over 4 h, as a result.

MOPCP094

Consistency in Measurement of Beam Phase and Beam Intensity Using Lock-in Amplifier and Oscilloscope Systems

cyclotron, monitoring, beam-transport, rfq

245

R. Koyama, M. Fujimaki, N. Fukunishi, A. Goto, M. Hemmi, O. Kamigaito, M. Kase, N. Sakamoto, K. Suda, T. Watanabe, K. Yamada
RIKEN Nishina Center, Wako, Japan

The RIKEN RI beam factory (RIBF) consists of four ring cyclotrons (RRC, fRC, IRC, and SRC) and two injectors (RILAC and AVF) which are all connected in cascade. RILAC, AVF, and RRC began operation in the 1980s, and fRC, IRC, and SRC were installed in 2006. Phase probes (PPs) are installed in all cyclotrons and beam transport lines of RIBF, and the beam-bunch signals that are detected nondestructively by these PPs are used for tuning of isochronous magnetic field of cyclotrons and for monitoring the beam phase and beam intensity. We mainly use a newly developed system that incorporates a lock-in amplifier (LIA; SR844, SRS) for those tuning and monitoring; however, in AVF and RRC, a conventional measurement method using an oscilloscope system (OSC; DSO6052A, Agilent) is used. In this study, we investigated the consistency in the measurements carried out using LIA and OSC systems by Fourier analyzing the observed data. Additionally, we investigated the resolution and measurement uncertainty of LIA and OSC.

MOPCP098

Influence of RF Magnetic Field on Ion Dynamics in IBA C400 Cyclotron

cyclotron, ion, radio-frequency, resonance

251

E. Samsonov, G.A. Karamysheva, S.A. Kostromin
JINR, Dubna, Moscow Region, Russia
Y. Jongen
IBA, Louvain-la-Neuve, Belgium

Magnetic components of RF field in C400 cyclotron being under development by IBA makes noticeable influence on ion dynamics. In particular, increase in the dees voltage along radius leads to corresponding phase compression of a bunch. Influence of the RF magnetic field on the bunch center phase deviation during acceleration and on radial ion axial motions have been also estimated numerically. RF magnetic field changes a central ion phase by only 2° RF. Calculations have also shown that RF magnetic field makes visible but pretty small influence on the radial motion of the ions ensuring some decrease in the radial amplitudes. No visible impact of the RF magnetic field on the axial motion has been detected. The results are compared for the two RF magnetic field maps: (i) obtained by Microwave Studio and, (ii) computed from RF electric field map by means of Maxwell' equations.

TUM2CIO01

Status of RIBF Accelerators at RIKEN

cyclotron, ion, ion-source, rfq

286

O. Kamigaito, S. Arai, T. Dantsuka, M. Fujimaki, T. Fujinawa, H. Fujisawa, N. Fukunishi, A. Goto, H. Hasebe, Y. Higurashi, K. Ikegami, E. Ikezawa, H. Imao, T. Kageyama, M. Kase, M. Kidera, M. Komiyama, H. Kuboki, K. Kumagai, T. Maie, M. Nagase, T. Nakagawa, M. Nakamura, J. Ohnishi, H. Okuno, N. Sakamoto, K. Suda, H. Watanabe, T. Watanabe, Y. Watanabe, K. Yamada, Y. Yano, S. Yokouchi
RIKEN Nishina Center, Wako, Japan

Recent developments and upgrade program in the near future at RIKEN RI-Beam Factory (RIBF) are presented. The beam intensity and available ion species are increasing at RIBF, owing to the continuous efforts that have been paid since the first beam in 2006. So far, we accelerated deuteron, helium, nitrogen, oxygen, aluminum, calcium, krypton, and uranium beams with the superconducting ring cyclotron, SRC. The extracted beam intensities reached 1,000 pnA for helium and oxygen beams. From the operational point of view, however, the intensity of the uranium beam should be much increased. We are, therefore, constructing a new injector linac for the RIBF, consisting of a superconducting ECR ion source, RFQ, and DTL, which will be commissioned in this fiscal year. By using this injector, we also aim at independent operation of the RIBF and GARIS facility for super-heavy element synthesis.

Slides TUM2CIO01 [4.914 MB]

TUA2CCO02

Induction Sector Cyclotron for Cluster Ions

ion, induction, cyclotron, focusing

314

K. Takayama, T. Adachi
KEK, Ibaraki, Japan
W. Jiang
Nagaoka University of Technology, Nagaoka, Niigata, Japan
Y. Oguri
TIT, Tokyo, Japan
H. Tsutsui
SHI, Tokyo, Japan

Funding: supported by Grant-in-Aid for Exploratory Research (KAKENHI 22265403)
A novel scheme of a sector cyclotron to accelerate extremely heavy cluster ions, called 'Induction Sector Cyclotron (ISC)', is described [1]. Its key feature is fast induction acceleration, which has been already demonstrated using the KEK 12 GeV proton synchrotron [2]. An ion bunch is accelerated and captured with pulse voltages generated by transformers. The acceleration and confinement in the longitudinal direction can be independently handled. The transformers are energized by the corresponding switching power supply, in which power solid-state devices are employed as switching elements and their turning on/off is maneuvered by gate signals digitally manipulated from the circulating beam signal of an ion bunch. Consequently the acceleration synchronizing with the revolution of any ion beam is always guaranteed. A cluster ion beam such as C-60, which so far there has been no way to repeatedly accelerate, can be accelerated from an extremely low velocity to a nearly light velocity. Its fundamental concept, beam dynamics, required key devices, and life time of a cluster ion beam will be discussed. A typical example of ISC is proposed at the conference.
[1] K.Takayama et al., submitted to Phys. Rev. Lett. (2010).
[2] K.Takayama et al., Phys. Rev. Lett. 98, 054801 (2007),
K.Takayama and R.Briggs (Eds.), 'Induction Accelerators' (Springer, 2010).

Slides TUA2CCO02 [1.781 MB]

WEM2CCO02

Operating Experience with the RF System for Superconducting Ring Cyclotron of RIBF

cyclotron, vacuum, cryogenics, pick-up

338

N. Sakamoto, M. Fujimaki, A. Goto, O. Kamigaito, M. Kase, R. Koyama, K. Suda, K. Yamada, S. Yokouchi
RIKEN Nishina Center, Wako, Japan

Since December 2006, Superconducting Ring Cyclotron (SRC) has been operational. Up to now, the beams of ²³⁸U, ⁴⁸Ca, pol-d, N, ⁴He have been provided for nuclear physics experiments. The SRC consists of 6 superconducting sector magnets, 4 accelerating cavities and one flattop cavity. Designed value of the acceleration voltage is 2 MV/turn. The gap voltage of 600 kV is excited with 130 kW rf power in the accelerating cavity. The cavities have been installed at four valley regions of 6 sector magnets and are exposed to a strong stray field of superconducting magnets. The strength of the magnetic field is as large as a few kilogauss. It is found that the condition of multipactor depends drastically on the strength of the stray field. How to treat the multipactor is one of the most important issues for stable operation of the SRC. This paper will discuss on our efforts to settle the problem concerning the cavities. By improving the vacuum, cooling, surface treatment and so on, we finally succeeded to minimize the break time due to the rf break down of the SRC cavities during experiments.

Slides WEM2CCO02 [9.291 MB]

THM1CIO01

Post-acceleration of High Intensity RIB through the CIME Cyclotron in the Frame of the SPIRAL2 Project at GANIL

cyclotron, ion, linac, ion-source

354

P. Bertrand, A. Savalle
GANIL, Caen, France

The cyclotron CIME is presently used at GANIL for the acceleration of SPIRAL1 radioactive beams. One of the goals of the SPIRAL2 project is to produce, post-accelerate and use in the existing experimental areas much higher intensity secondary beams induced by uranium fission like neutron-rich krypton, xenon, tin isotopes, and many others. Intensity may reach 10¹⁰ pps. Specific developments are needed for secondary beam diagnostics. Improvement of mass separation is also necessary, and the Vertical Mass Separator (VMS) is specially developed for this purpose. However, the main concern is related to the high radioactivity linked to RIB high intensity. Safety and radioprotection issues will require modifications of the installation with special care for the maintenance of the cyclotron. The experience of the SPIRAL1 beams, in terms of beam losses and equipment contamination, is especially useful to define the necessary modifications.

Slides THM1CIO01 [6.133 MB]

THM1CIO02

Acceleration above the Coulomb Barrier - Completion of the ISAC-II Project at TRIUMF

linac, ion, vacuum, cyclotron

359

R.E. Laxdal
TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada

The ISAC-II project at TRIUMF was proposed to boost the final energy of the radioactive ion beams of the TRIUMF ISAC facility above the Coulomb barrier. The nominal goal of 6.5 MeV/u for ions with A/q=6 was recently achieved. The ISAC-II post-accelerator consists of 40 MV of installed heavy ion superconducting linac to broaden the energy reach and a charge state booster to broaden the mass reach. Details of the project and the ISAC-II commissioning and operation will be presented.

Slides THM1CIO02 [3.619 MB]

THA1CIO01

FFAG Developments in Japan

proton, optics, lattice, betatron

376

Y. Mori
KURRI, Osaka, Japan

Recent activities of the research and development works on FFAG accelerators in Japan are reviewed in this talk.

Slides THA1CIO01 [27.606 MB]

THA1CIO02

First Commissioning Results from the Non-Scaling FFAG Accelerator, EMMA

septum, controls, injection, lattice

384

S.L. Smith
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom

The first results from commissioning EMMA - the Electron Model of Many Applications- are summarised in this paper. EMMA is a 10 to 20 MeV electron ring designed to test our understanding of beam dynamics in a relativistic linear non-scaling fixed field alternating gradient accelerator (FFAG). EMMA will be the world's first non-scaling FFAG and the paper will outline the characteristics of the beam injected in to the accelerator as well as summarising the results of the 4 sector 'gantry-type' commissioning which took place at Daresbury Laboratory. The paper will report on recent progress made with the full EMMA ring commissioning, giving details of tune and orbit measurements as well as their correction to the desired lattice.

Slides THA1CIO02 [5.404 MB]

THA1CIO03

Innovations in Fixed-Field Accelerators: Design and Simulation

focusing, cyclotron, synchrotron, controls

389

C. Johnstone
Fermilab, Batavia, USA
M. Berz, K. Makino
MSU, East Lansing, Michigan, USA
S.R. Koscielniak
TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada
P. Snopok
UCR, Riverside, California, USA

The drive for high beam power, high duty cycle, and reliable beams has focused world interest on fixed field accelerators, notably Fixed-field Alternating Gradient accelerators (FFAGs) ' with cyclotrons representing a specific class of fixed-field accelerators. Recently, the concept of isochronous orbits has been developed for nonscaling FFAGs using new methodologies in FFAG design. The property of isochronous orbits enables the simplicity of fixed RF and, by tailoring a nonlinear radial field profile, the FFAG is isochronous well into the relativistic regime. The machine proposed here has the high current advantage and duty cycle of the cyclotron in combination with the strong focusing, smaller losses, and energy variability that are more typical of the synchrotron. Further, compact high-performance devices are often are operated in a regime where space charge effects become significant, but are complicated to analyze in fixed-field accelerators because of the cross talk between beams at different nearby radii. A new space charge simulation approach is under development in the code COSY INFINITY. This presentation reports on advances in FFAG accelerator design and simulation.

Slides THA1CIO03 [1.527 MB]