CYCLOTRONS 2010 - List of Keywords (resonance)

Paper	Title	Other Keywords	Page
MOPCP016	Present Status of the RCNP Cyclotron Facility	cyclotron, ion, proton, plasma	78
	K. Hatanaka, M. Fukuda, M. Kibayashi, S. Morinobu, K. Nagayama, T. Saito, H. Tamura, T. Yorita RCNP, Osaka, Japan
	The Research Center for Nuclear Physics (RCNP) cyclotron cascade system has been operated to provide high quality beams for various experiments. In order to increase the physics research opportunities, the Azimuthally Varying Field (AVF) cyclotron facility was upgraded recently. A flat-topping system and an 18-GHz superconducting Electron Cyclotron Resonance (ECR) ion source were introduced to improve the beam's quality and intensity. A new beam line was installed to diagnose the characteristics of the beam to be injected into the ring cyclotron and to bypass the ring cyclotron and directly transport low energy beams from the AVF cyclotron to experimental halls. A separator is equipped to provide RI beams produced by fusion reactions at low energy and by projectile fragmentations at high energy. Developments have been continued to increase secondary beams as white neutrons, ultra cold neutrons, muons and unstable nucleri.

MOPCP024	Design of RF System for Compact AVF Cyclotron	cyclotron, magnet-design, simulation, proton	99
	J.H. Oh, J.-S. Chai, H.W. Kim, B.N. Lee SKKU, Suwon, Republic of Korea
	RF system is one of the most important parts for producing good and efficient accelerator system. The ion beam will be derived by a K100 SSC (Separated-Sector-Cyclotron). 8 MeV SF(Sector-focused) Cyclotron which produces 8 MeV proton beam is used as injector of K100 SSC cyclotron. In this paper, we designed RF system including RF cavity. The total specification of system is on the following. The frequency of this RF system is 70 MHz coaxial type cavity. Also we applied 4th harmonic, dee voltage of 50KV. We simulated the RF system using commercially available simulator, CST Microwave studio. KEYWORDS : Cyclotron, , RF system

MOPCP033	Magnet Design of 70 MeV Separate Sector Cyclotron (KoRIA)	cyclotron, simulation, extraction, focusing	120
	Kh.M. Gad, J.-S. Chai, H.W. Kim, B.N. Lee, J.H. Oh, J.A. Park, H.S. Song SKKU, Suwon, Republic of Korea
	Funding: Ministry of Education, Science and Technology, Republic of Korea Department of Energy Science and School of Information and Communication Engineering of SungKyunKwan University A k=100 separated sector cyclotron is being designed in SKKU university South Korea, this cyclotron is considered the main drive for ISOL to produce ~ 70-100 MeV proton beam and ~35-50 MeV deuteron beam for production of radioactive material as a basic nuclear research, in this paper we will describe Opera 3D (Tosca) numerical simulation for determining the basic magnet parameters, magnet material, deformation , imperfection fields and preliminary ion beam dynamics study for verifying the focusing properties of the designed magnet

MOPCP049	Ion Source Related Research Work at JYFL	ion, ion-source, electron, plasma	150
	H. A. Koivisto, V.P. Aho, J. Ärje, T. Kalvas, J.A. Kauppinen, J.P. Kommpula, T. Ropponen, O.A. Tarvainen, V.A. Toivanen JYFL, Jyväskylä, Finland
	In this article the work of the JYFL ion source group will be presented. New bremsstrahlung measurements were carried out in order to compare the results with different electron heating models, especially defining the endpoint energy of the bremsstrahlung spectra. A project to obtain new information about the ion temperatures and their time evolution has been initiated. The study will be performed using spectroscopic techniques measuring the ion temperature through the Doppler broadening of emission lines. The objective is to reveal accurate information about the time evolution of highly charged ions in the ECRIS plasma. The work also includes frequency tuning experiments, beam quality experiments and tests with a so-called collar structure. The beneficial effect of collar was first tested and noticed with the ECR ion sources by the KVI ion source group and has been shortly confirmed at JYFL in collaboration with the KVI research group. The JYFL ion source group is also developing a low energy electron gun for the spacecraft applications. The results of the development work can possibly be applied also with the ion sources in order to increase the density of cold electrons.

MOPCP057	A Compact Solution for DDS-Generator, Turn-on and Protections in RF Accelerator Systems	controls, cyclotron, pick-up, radio-frequency	159
	A.C. Caruso, F. Consoli, A. Spartà INFN/LNS, Catania, Italy A. Longhitano ALTEK, San Gregorio (CATANIA), Italy
	A single compact rack that includes a Direct Digital Synthesizer generator, a turn-on and protection system provides the smart solution in RF accelerator systems. It synthesizes a high stable RF signal up to 120 MHz, turns the power on into the RF cavities through a step-ramp modulator, protects the RF system against mismatching, sparks and multipactoring. A preliminary prototype has been designed, assembled and tested on the RF system of the k-800 superconducting cyclotron at Infn-Lns. This solution is part of the new computer-based RF control system. The hardware, software, and first test results will be shown in this paper.

MOPCP060	Design, Construction and Commissioning of the 100 kW RF Amplifier for CYCIAE-100	cyclotron, vacuum, site, factory	168
	Z.G. Yin, B. Ji, Z.G. Li, T.J. Zhang, Z.L. Zhao CIAE, Beijing, People's Republic of China S.D. Wei, H.C. Xiao, Y. Xie CASIC, Beijing, People's Republic of China
	As a major part of the BRIF project, the 100 MeV high intensity cyclotron being constructed at CIAE, CYCIAE-100, will provide 200 μA proton beam ranging from 75 MeV to 100 MeV for RIB production. Two identical 100 kW RF amplifiers will be used to drive two cavities independently to accelerate H⁻ beam up to 100 MeV. The detail technical specification has been investigated, fixed, and initial design has been finished by CIAE. Then, the construction design and manufacture is implemented by China Academy of Aero and Space, and the on site commissioning is successful by mutual efforts. The final commissioning is under way with a full scale prototype cavity at CIAE. A general description of the CYCIAE-100 RF system design will be given, as well as the review of 100 kW amplifier design. In the commissioning of the amplifier with dummy load, different high order resonances are found when operated at different frequencies between 42 MHz to 46 MHz. An equivalent circuit model is carried out to hunt down the problems. The model and related analysis will be reported together with the process and results of high power test with the cavity load through ~35 meters six inch rigid transmission line.

MOPCP064	Amplifier Test Stand for the CRM Cyclotron	cyclotron, impedance, simulation, feedback	177
	Z.G. Yin, K. Fei, B. Ji, P.Z. Li, G.S. Liu, G.F. Song, T.J. Zhang CIAE, Beijing, People's Republic of China C.J. Yu CASIC, Beijing, People's Republic of China
	Abstract: The final stage amplifier stability proves to be an important issue in the process of commissioning CRM cyclotron at CIAE. An air cooled 4CX15,000 tube final stage has been designed to evaluate the anode circuit and neutralization, both of which are weak points of the CRM cyclotron amplifier. Instead of strip line, the design of the new anode structure adopts coaxial form, resulting in less chance of parasitic resonance in the circuits. A tunable neutralization circuits is also included in the design, giving an opportunity to better stability in high power operations. First, the instability in CRM RF system will be analyzed in this paper followed with the new amplifier designs including the tube working line calculations, input/output circuit calculations and finite integral simulations. The mechanical design for tube socket and the anode tank have been successfully carried out using the data provided in this paper. The final stage amplifier is then fabricated, assembled and commissioned. In the power test with dummy load, more than 9.2kW RF fundamental power is provided at the frequency of 44MHz.

MOPCP067	Design and Primary Test of Full Scale Cavity of CYCIAE-100	simulation, cyclotron, impedance, coupling	183
	B. Ji, P.Z. Li, J. Lin, G.S. Liu, G.F. Pan, Z.H. Wang, J.S. Xing, Z.G. Yin, S.P. Zhang, T.J. Zhang, Z.L. Zhao CIAE, Beijing, People's Republic of China
	The engineering of the RF cavity for cyclotron concerns several aspects of the system including vacuum, cooling, mechanical support etc, Sometime it is even more complex than the RF design itself. With limit space in a compact cyclotron, in order to achieve a voltage distribution of 60kV in central orbit and 120kV for outer orbit, a double stem double gap λ by 2 cavities has been designed for CYCIAE-100[1]. The RF resonance of the cavity is simulated [1] by finite integral codes, while the thermal analysis and mechanical tolerance are studied using other approaches [2, 3]. The mechanical design and fabrications is then carried out under these directions, resulting in a full scale cavity model. The simulations and the mechanical design will be reported in this paper, followed with low level measurement results of quality factor, shunt impedance curve along accelerating gap etc. After surface polishing, the measurement yields an unloaded Q value of 9300, which matches well with the simulation with a neglectable difference of several hundreds. The high power test of the cavity will be carried out later, and will be given in separate paper presented at this conference. [1] Tianjue Zhang,et al, 100 MeV H⁻ Cyclotron as an RIB Driving Accelerator, CYC 2004 [2] Yuanjie Bi, et al, The Study on RF Cavity Tolerance for CYCIAE-100, CYC 2007 [3] S.M. Wei, et al, Thermal Analysis of RF Cavity for CYCIAE-100, CYC 2007

MOPCP070	Design of IBA Cyclone 30XP Cyclotron Magnet	cyclotron, extraction, quadrupole, proton	189
	E. Forton, M. Abs, W.J.G.M. Kleeven, B. Nactergal, D. Neuvéglise, S. Zaremba IBA, Louvain-la-Neuve, Belgium
	IBA is developing an evolution of its famous Cyclone 30 cyclotron. The Cyclone 30xp will be a multi-particle, multiport cyclotron capable of accelerating alpha particles up to 30 MeV, deuteron (D-) beams between 7.5 and 15 MeV and proton (H⁻) beams between 15 and 30 MeV. The magnet system has been improved with IBA Cyclone 18/9 and Cyclone 70 features. Coil dimensions have been updated in order to raise the free space in the median plane. This allows the mounting of a retractable electrostatic deflector system for the extraction of the alpha particle beam. Gradient corrector pole extensions have been added to ease the alpha beam extraction. Finally, compensation for relativistic effects between H⁻ (q/m=1/1) and D-/alpha (q/m=1/2) beams is made by movable iron inserts located in two valleys, as in IBA Cyclone 18/9 cyclotrons. These modifications could have an adverse effect on the flutter. In addition, the second harmonic induced by the movable iron inserts drives the machine in the 2.ν_r=2 resonance close to the extraction. As a consequence, modifications on the pole sectors and chamfers have been made in order to improve the flutter and eliminate the harmful resonance.

MOPCP078	Study of Magnetic Field Imperfections of Kolkata Superconducting Cyclotron	cyclotron, simulation	209
	J. Pradhan, R.K. Bhandari, U. Bhunia, J. Debnath, M.K. Dey, C. Mallik, S. Paul DAE/VECC, Calcutta, India
	Analysis of the magnetic data obtained during the magnetic field mapping of Kolkata superconducting cyclotron showed imperfections in the main magnetic field. Since the main magnet of the superconducting cyclotron is three fold rotationally symmetric, any deviation from this symmetry creates imperfections in the magnetic field. Generally, 1st and 2nd harmonic components are inherently present in the field due to assembling errors in iron/coil. A major portion of these imperfections is attributed to the misplacement/tilting of the iron pole tip with respect to coil. The error in positioning of main superconducting coil with respect to surrounding iron produces another imperfection. Pole tip deformation due to rise of temperature produces field imperfection. This paper reports the various possible sources of imperfection in general and their estimation. The calculation was compared with measured data to find out the actual cause of imperfections and necessary corrections

MOPCP085	Application of HTS Wire to Magnets	dipole, superconductivity, synchrotron, coupling	224
	K. Hatanaka, M. Fukuda, T. Yorita RCNP, Osaka, Japan T. Kawaguchi KT Science Ltd., Akashi, Japan K. Noda NIRS, Chiba-shi, Japan Y. Sakemi CYRIC, Sendai, Japan
	We are developing magnets with High Temperature Superconducting (HTS) wire. A scanning magnet was designed, fabricated, and tested for its suitability as beam scanner. After successful cooling tests, the magnet performance was studied using DC and AC currents. In AC mode, the magnet was operated at frequencies of 30-59 Hz and a temperature of 77 K as well as 10-20 Hz and 20 K. The power loss dissipated in the coils was measured and compared with the model calculations. The observed loss per cycle was independent of the frequency and the scaling law of the excitation current was consistent with theoretical predictions for hysteretic losses in HTS wires. A 3 T dipole maget is under fablication now.

MOPCP098	Influence of RF Magnetic Field on Ion Dynamics in IBA C400 Cyclotron	cyclotron, ion, acceleration, radio-frequency	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.

WEM1CIO03	New Tools for the Improvement of Beam Brightness in ECR Ion Sources	plasma, electron, ion, simulation	327
	S. Gammino, L. Celona, G. Ciavola, D. Mascali INFN/LNS, Catania, Italy
	According to the model that has driven the development of ECRIS in the last years, a large variation of the pumping microwave frequency (order of GHz) along with the proportional increase of the magnetic field boosts the extracted current for each charge state because of a larger plasma density. Recent experiments have demonstrated that even slight frequency's changes (of the order of MHz) considerably influence the output current, and what's more important, even the extracted beam properties (beam shape, brightness and emittance) are affected. A number of tests have been carried out in the last few years and they will be reviewed along with the results of numerical simulations which are able to explain the observed phenomena. The frequency has been systematically changed and the beam output has been recorded either in terms of charge state distributions and beam emittance. The detected bremsstrahlung X-rays are additionally analysed: they give insights about the electron energy distribution function (EEDF). An overview about the possible future improvements of ECR ion source will be given.

FRM1CIO03	IBA-JINR 400 MeV/u Superconducting Cyclotron for Hadron Therapy	cyclotron, ion, extraction, proton	404
	N.A. Morozov, V. Aleksandrov, S. Gurskiy, G.A. Karamysheva, N.Yu. Kazarinov, S.A. Kostromin, E. Samsonov, V. Shevtsov, G. Shirkov, E. Syresin, A. Tuzikov JINR, Dubna, Moscow Region, Russia M. Abs, A. Blondin, Y. Jongen, W.J.G.M. Kleeven, D. Vandeplassche, S. Zaremba IBA, Louvain-la-Neuve, Belgium O. Karamyshev JINR/DLNP, Dubna, Moscow region, Russia
	The compact superconducting isochronous cyclotron C400 [1] has been designed by the IBA-JINR collaboration. It will be the first cyclotron in the world capable of delivering protons, carbon and helium ions for cancer treatment. The cyclotron construction is started this year within the framework of the ARCHADE project [2] (Caen, France). ¹²C⁶⁺ and ⁴He²⁺ ions will be accelerated to 400 MeV/u energy and extracted by the electrostatic deflector, H²⁺ ions will be accelerated to the energy of 265 MeV/u and extracted by stripping. The magnet yoke has a diameter of 6.6 m, the total weight of the magnet is about 700 t. The designed magnetic field corresponds to 4.5 T in the hills and 2.45 T in the valleys. Superconducting coils will be enclosed in a cryostat; all other parts of the cyclotron will be warm. Three external ion sources will be mounted on the switching magnet on the injection line located below the cyclotron. The main parameters of the cyclotron, its design, the current status of the development work on the cyclotron systems are presented. [1] Y.Jongen et al, 'IBA C400 Cyclotron Project for Hadron Therapy', The 18th International Conference on Cyclotrons and their Applications Cyclotrons 2007, Italy 2007. [2] http://archade.fr/
	Slides FRM1CIO03 [1.996 MB]

Paper

Title

Other Keywords

Page

MOPCP016

Present Status of the RCNP Cyclotron Facility

cyclotron, ion, proton, plasma

78

K. Hatanaka, M. Fukuda, M. Kibayashi, S. Morinobu, K. Nagayama, T. Saito, H. Tamura, T. Yorita
RCNP, Osaka, Japan

The Research Center for Nuclear Physics (RCNP) cyclotron cascade system has been operated to provide high quality beams for various experiments. In order to increase the physics research opportunities, the Azimuthally Varying Field (AVF) cyclotron facility was upgraded recently. A flat-topping system and an 18-GHz superconducting Electron Cyclotron Resonance (ECR) ion source were introduced to improve the beam's quality and intensity. A new beam line was installed to diagnose the characteristics of the beam to be injected into the ring cyclotron and to bypass the ring cyclotron and directly transport low energy beams from the AVF cyclotron to experimental halls. A separator is equipped to provide RI beams produced by fusion reactions at low energy and by projectile fragmentations at high energy. Developments have been continued to increase secondary beams as white neutrons, ultra cold neutrons, muons and unstable nucleri.

MOPCP024

Design of RF System for Compact AVF Cyclotron

cyclotron, magnet-design, simulation, proton

99

J.H. Oh, J.-S. Chai, H.W. Kim, B.N. Lee
SKKU, Suwon, Republic of Korea

RF system is one of the most important parts for producing good and efficient accelerator system. The ion beam will be derived by a K100 SSC (Separated-Sector-Cyclotron). 8 MeV SF(Sector-focused) Cyclotron which produces 8 MeV proton beam is used as injector of K100 SSC cyclotron. In this paper, we designed RF system including RF cavity. The total specification of system is on the following. The frequency of this RF system is 70 MHz coaxial type cavity. Also we applied 4th harmonic, dee voltage of 50KV. We simulated the RF system using commercially available simulator, CST Microwave studio.
KEYWORDS : Cyclotron, , RF system

MOPCP033

Magnet Design of 70 MeV Separate Sector Cyclotron (KoRIA)

cyclotron, simulation, extraction, focusing

120

Kh.M. Gad, J.-S. Chai, H.W. Kim, B.N. Lee, J.H. Oh, J.A. Park, H.S. Song
SKKU, Suwon, Republic of Korea

Funding: Ministry of Education, Science and Technology, Republic of Korea Department of Energy Science and School of Information and Communication Engineering of SungKyunKwan University
A k=100 separated sector cyclotron is being designed in SKKU university South Korea, this cyclotron is considered the main drive for ISOL to produce ~ 70-100 MeV proton beam and ~35-50 MeV deuteron beam for production of radioactive material as a basic nuclear research, in this paper we will describe Opera 3D (Tosca) numerical simulation for determining the basic magnet parameters, magnet material, deformation , imperfection fields and preliminary ion beam dynamics study for verifying the focusing properties of the designed magnet

MOPCP049

Ion Source Related Research Work at JYFL

ion, ion-source, electron, plasma

150

H. A. Koivisto, V.P. Aho, J. Ärje, T. Kalvas, J.A. Kauppinen, J.P. Kommpula, T. Ropponen, O.A. Tarvainen, V.A. Toivanen
JYFL, Jyväskylä, Finland

In this article the work of the JYFL ion source group will be presented. New bremsstrahlung measurements were carried out in order to compare the results with different electron heating models, especially defining the endpoint energy of the bremsstrahlung spectra. A project to obtain new information about the ion temperatures and their time evolution has been initiated. The study will be performed using spectroscopic techniques measuring the ion temperature through the Doppler broadening of emission lines. The objective is to reveal accurate information about the time evolution of highly charged ions in the ECRIS plasma. The work also includes frequency tuning experiments, beam quality experiments and tests with a so-called collar structure. The beneficial effect of collar was first tested and noticed with the ECR ion sources by the KVI ion source group and has been shortly confirmed at JYFL in collaboration with the KVI research group. The JYFL ion source group is also developing a low energy electron gun for the spacecraft applications. The results of the development work can possibly be applied also with the ion sources in order to increase the density of cold electrons.

MOPCP057

A Compact Solution for DDS-Generator, Turn-on and Protections in RF Accelerator Systems

controls, cyclotron, pick-up, radio-frequency

159

A.C. Caruso, F. Consoli, A. Spartà
INFN/LNS, Catania, Italy
A. Longhitano
ALTEK, San Gregorio (CATANIA), Italy

A single compact rack that includes a Direct Digital Synthesizer generator, a turn-on and protection system provides the smart solution in RF accelerator systems. It synthesizes a high stable RF signal up to 120 MHz, turns the power on into the RF cavities through a step-ramp modulator, protects the RF system against mismatching, sparks and multipactoring. A preliminary prototype has been designed, assembled and tested on the RF system of the k-800 superconducting cyclotron at Infn-Lns. This solution is part of the new computer-based RF control system. The hardware, software, and first test results will be shown in this paper.

MOPCP060

Design, Construction and Commissioning of the 100 kW RF Amplifier for CYCIAE-100

cyclotron, vacuum, site, factory

168

Z.G. Yin, B. Ji, Z.G. Li, T.J. Zhang, Z.L. Zhao
CIAE, Beijing, People's Republic of China
S.D. Wei, H.C. Xiao, Y. Xie
CASIC, Beijing, People's Republic of China

As a major part of the BRIF project, the 100 MeV high intensity cyclotron being constructed at CIAE, CYCIAE-100, will provide 200 μA proton beam ranging from 75 MeV to 100 MeV for RIB production. Two identical 100 kW RF amplifiers will be used to drive two cavities independently to accelerate H⁻ beam up to 100 MeV. The detail technical specification has been investigated, fixed, and initial design has been finished by CIAE. Then, the construction design and manufacture is implemented by China Academy of Aero and Space, and the on site commissioning is successful by mutual efforts. The final commissioning is under way with a full scale prototype cavity at CIAE. A general description of the CYCIAE-100 RF system design will be given, as well as the review of 100 kW amplifier design. In the commissioning of the amplifier with dummy load, different high order resonances are found when operated at different frequencies between 42 MHz to 46 MHz. An equivalent circuit model is carried out to hunt down the problems. The model and related analysis will be reported together with the process and results of high power test with the cavity load through ~35 meters six inch rigid transmission line.

MOPCP064

Amplifier Test Stand for the CRM Cyclotron

cyclotron, impedance, simulation, feedback

177

Z.G. Yin, K. Fei, B. Ji, P.Z. Li, G.S. Liu, G.F. Song, T.J. Zhang
CIAE, Beijing, People's Republic of China
C.J. Yu
CASIC, Beijing, People's Republic of China

Abstract: The final stage amplifier stability proves to be an important issue in the process of commissioning CRM cyclotron at CIAE. An air cooled 4CX15,000 tube final stage has been designed to evaluate the anode circuit and neutralization, both of which are weak points of the CRM cyclotron amplifier. Instead of strip line, the design of the new anode structure adopts coaxial form, resulting in less chance of parasitic resonance in the circuits. A tunable neutralization circuits is also included in the design, giving an opportunity to better stability in high power operations. First, the instability in CRM RF system will be analyzed in this paper followed with the new amplifier designs including the tube working line calculations, input/output circuit calculations and finite integral simulations. The mechanical design for tube socket and the anode tank have been successfully carried out using the data provided in this paper. The final stage amplifier is then fabricated, assembled and commissioned. In the power test with dummy load, more than 9.2kW RF fundamental power is provided at the frequency of 44MHz.

MOPCP067

Design and Primary Test of Full Scale Cavity of CYCIAE-100

simulation, cyclotron, impedance, coupling

183

B. Ji, P.Z. Li, J. Lin, G.S. Liu, G.F. Pan, Z.H. Wang, J.S. Xing, Z.G. Yin, S.P. Zhang, T.J. Zhang, Z.L. Zhao
CIAE, Beijing, People's Republic of China

The engineering of the RF cavity for cyclotron concerns several aspects of the system including vacuum, cooling, mechanical support etc, Sometime it is even more complex than the RF design itself. With limit space in a compact cyclotron, in order to achieve a voltage distribution of 60kV in central orbit and 120kV for outer orbit, a double stem double gap λ by 2 cavities has been designed for CYCIAE-100[1]. The RF resonance of the cavity is simulated [1] by finite integral codes, while the thermal analysis and mechanical tolerance are studied using other approaches [2, 3]. The mechanical design and fabrications is then carried out under these directions, resulting in a full scale cavity model. The simulations and the mechanical design will be reported in this paper, followed with low level measurement results of quality factor, shunt impedance curve along accelerating gap etc. After surface polishing, the measurement yields an unloaded Q value of 9300, which matches well with the simulation with a neglectable difference of several hundreds. The high power test of the cavity will be carried out later, and will be given in separate paper presented at this conference.
[1] Tianjue Zhang,et al, 100 MeV H⁻ Cyclotron as an RIB Driving Accelerator, CYC 2004
[2] Yuanjie Bi, et al, The Study on RF Cavity Tolerance for CYCIAE-100, CYC 2007
[3] S.M. Wei, et al, Thermal Analysis of RF Cavity for CYCIAE-100, CYC 2007

MOPCP070

Design of IBA Cyclone 30XP Cyclotron Magnet

cyclotron, extraction, quadrupole, proton

189

E. Forton, M. Abs, W.J.G.M. Kleeven, B. Nactergal, D. Neuvéglise, S. Zaremba
IBA, Louvain-la-Neuve, Belgium

IBA is developing an evolution of its famous Cyclone 30 cyclotron. The Cyclone 30xp will be a multi-particle, multiport cyclotron capable of accelerating alpha particles up to 30 MeV, deuteron (D-) beams between 7.5 and 15 MeV and proton (H⁻) beams between 15 and 30 MeV. The magnet system has been improved with IBA Cyclone 18/9 and Cyclone 70 features. Coil dimensions have been updated in order to raise the free space in the median plane. This allows the mounting of a retractable electrostatic deflector system for the extraction of the alpha particle beam. Gradient corrector pole extensions have been added to ease the alpha beam extraction. Finally, compensation for relativistic effects between H⁻ (q/m=1/1) and D-/alpha (q/m=1/2) beams is made by movable iron inserts located in two valleys, as in IBA Cyclone 18/9 cyclotrons. These modifications could have an adverse effect on the flutter. In addition, the second harmonic induced by the movable iron inserts drives the machine in the 2.ν_r=2 resonance close to the extraction. As a consequence, modifications on the pole sectors and chamfers have been made in order to improve the flutter and eliminate the harmful resonance.

MOPCP078

Study of Magnetic Field Imperfections of Kolkata Superconducting Cyclotron

cyclotron, simulation

209

J. Pradhan, R.K. Bhandari, U. Bhunia, J. Debnath, M.K. Dey, C. Mallik, S. Paul
DAE/VECC, Calcutta, India

Analysis of the magnetic data obtained during the magnetic field mapping of Kolkata superconducting cyclotron showed imperfections in the main magnetic field. Since the main magnet of the superconducting cyclotron is three fold rotationally symmetric, any deviation from this symmetry creates imperfections in the magnetic field. Generally, 1st and 2nd harmonic components are inherently present in the field due to assembling errors in iron/coil. A major portion of these imperfections is attributed to the misplacement/tilting of the iron pole tip with respect to coil. The error in positioning of main superconducting coil with respect to surrounding iron produces another imperfection. Pole tip deformation due to rise of temperature produces field imperfection. This paper reports the various possible sources of imperfection in general and their estimation. The calculation was compared with measured data to find out the actual cause of imperfections and necessary corrections

MOPCP085

Application of HTS Wire to Magnets

dipole, superconductivity, synchrotron, coupling

224

K. Hatanaka, M. Fukuda, T. Yorita
RCNP, Osaka, Japan
T. Kawaguchi
KT Science Ltd., Akashi, Japan
K. Noda
NIRS, Chiba-shi, Japan
Y. Sakemi
CYRIC, Sendai, Japan

We are developing magnets with High Temperature Superconducting (HTS) wire. A scanning magnet was designed, fabricated, and tested for its suitability as beam scanner. After successful cooling tests, the magnet performance was studied using DC and AC currents. In AC mode, the magnet was operated at frequencies of 30-59 Hz and a temperature of 77 K as well as 10-20 Hz and 20 K. The power loss dissipated in the coils was measured and compared with the model calculations. The observed loss per cycle was independent of the frequency and the scaling law of the excitation current was consistent with theoretical predictions for hysteretic losses in HTS wires. A 3 T dipole maget is under fablication now.

MOPCP098

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

cyclotron, ion, acceleration, radio-frequency

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.

WEM1CIO03

New Tools for the Improvement of Beam Brightness in ECR Ion Sources

plasma, electron, ion, simulation

327

S. Gammino, L. Celona, G. Ciavola, D. Mascali
INFN/LNS, Catania, Italy

According to the model that has driven the development of ECRIS in the last years, a large variation of the pumping microwave frequency (order of GHz) along with the proportional increase of the magnetic field boosts the extracted current for each charge state because of a larger plasma density. Recent experiments have demonstrated that even slight frequency's changes (of the order of MHz) considerably influence the output current, and what's more important, even the extracted beam properties (beam shape, brightness and emittance) are affected. A number of tests have been carried out in the last few years and they will be reviewed along with the results of numerical simulations which are able to explain the observed phenomena. The frequency has been systematically changed and the beam output has been recorded either in terms of charge state distributions and beam emittance. The detected bremsstrahlung X-rays are additionally analysed: they give insights about the electron energy distribution function (EEDF). An overview about the possible future improvements of ECR ion source will be given.

FRM1CIO03

IBA-JINR 400 MeV/u Superconducting Cyclotron for Hadron Therapy

cyclotron, ion, extraction, proton

404

N.A. Morozov, V. Aleksandrov, S. Gurskiy, G.A. Karamysheva, N.Yu. Kazarinov, S.A. Kostromin, E. Samsonov, V. Shevtsov, G. Shirkov, E. Syresin, A. Tuzikov
JINR, Dubna, Moscow Region, Russia
M. Abs, A. Blondin, Y. Jongen, W.J.G.M. Kleeven, D. Vandeplassche, S. Zaremba
IBA, Louvain-la-Neuve, Belgium
O. Karamyshev
JINR/DLNP, Dubna, Moscow region, Russia

The compact superconducting isochronous cyclotron C400 [1] has been designed by the IBA-JINR collaboration. It will be the first cyclotron in the world capable of delivering protons, carbon and helium ions for cancer treatment. The cyclotron construction is started this year within the framework of the ARCHADE project [2] (Caen, France). ¹²C⁶⁺ and ⁴He²⁺ ions will be accelerated to 400 MeV/u energy and extracted by the electrostatic deflector, H²⁺ ions will be accelerated to the energy of 265 MeV/u and extracted by stripping. The magnet yoke has a diameter of 6.6 m, the total weight of the magnet is about 700 t. The designed magnetic field corresponds to 4.5 T in the hills and 2.45 T in the valleys. Superconducting coils will be enclosed in a cryostat; all other parts of the cyclotron will be warm. Three external ion sources will be mounted on the switching magnet on the injection line located below the cyclotron. The main parameters of the cyclotron, its design, the current status of the development work on the cyclotron systems are presented.
[1] Y.Jongen et al, 'IBA C400 Cyclotron Project for Hadron Therapy', The 18th International Conference on Cyclotrons and their Applications Cyclotrons 2007, Italy 2007.
[2] http://archade.fr/

Slides FRM1CIO03 [1.996 MB]