CYCLOTRONS 2010 - List of Keywords (electron)

Paper	Title	Other Keywords	Page
MOM1CIO02	Eighty Years of Cyclotrons	cyclotron, ion, focusing, proton	1
	M.K. Craddock UBC & TRIUMF, Vancouver, British Columbia, Canada
	Lawrence's invention of the cyclotron in 1930 not only revolutionized nuclear physics, but proved the starting point for a whole variety of recirculating accelerators, from microtrons to FFAGs to synchrotrons, that have had an enormous impact in almost every branch of science and several areas of medicine and industry. Cyclotrons (i.e. fixed-field accelerators) themselves have proved remarkably adaptable, incorporating a variety of new ideas and technologies over the years: frequency modulation, edge focusing, AG focusing, axial and azimuthal injection, ring geometries, stripping extraction, superconducting magnets and rf… Long may they flourish!
	Slides MOM1CIO02 [7.108 MB]

MOA2CIO01	HIRFL-CSR Facility Status and Development	ion, target, extraction, injection	37
	Y.J. Yuan, X.H. Cai, D.Q. Gao, Y. He, L.Z. Ma, X. Ma, R.S. Mao, Y.W. Su, X.L. Tu, J.W. Xia, H.S. Xu, Z. Xu, J.C. Yang, X.D. Yang, X.T. Yang, Y.P. Yang, W. Zhang, H.W. Zhao IMP, Lanzhou, People's Republic of China
	The HIRFL-CSR facility come into operation by the end of 2007. During operation in recent years, CSR supplied beam for experiments at several terminals and inside both CSRm and CSRe rings. The experiments covers high resolution mass measurement, cancer therapy research, neutron wall, atomic physics using electron target and internal gas target, using injection beam mainly from the SFC of cyclotron injector. New methods and further developments are required to improve the performance of CSR system including multi-gradients measurement method for beam spot commissioning and beam transfer, nonlinear effect correction and stabilization of isochronous mode of CSRe. For suppling of heverier ion beam with proper ernergy, the cyclotron complex should be enhanced and new injector is proposed to replace SFC as injector of SSC.
	Slides MOA2CIO01 [3.766 MB]

MOPCP044	New Magnetic Einzel Lens and Its Beam Optical Features	focusing, optics, ion, controls	141
	M.H. Rashid, R.K. Bhandari, C. Mallik DAE/VECC, Calcutta, India
	Magnetic cylindrical lens is used mostly in beam lines to focus and transport low energy beam. It is well known that focusing power of a magnetic solenoid lens depends on the ratio of particle momentum and electric charge. A solenoid rotates also an ion beam while focusing it and the phase space areas of the beam in x- and y-plane get entangled and increased. The paper reported here describes an effort to design a new magnetic Einzel lens using a pair of Glaser lens in anti-solenoid mode for the first time to get zero rotation of the exit beam. Analytical formulae have been generated to deduce the scalar magnetic potential and field along the central axis of the lens. Thereafter, beam optics and particle tracking is done using the combined field of a pair of Glaser Lenses constituting the magnetic Einzel lens. The required focusing power of the designed lens is achieved for a beam of given rigidity.

MOPCP047	Analysis of Beam Quality Optimization of Bucket Ion Source	ion, ion-source, proton, plasma	147
	Y.H. Xie, C.D. Hu, C.C. Jiang, L.Z. Liang, S. Liu, Y.L. Xie ASIPP, Hefei, People's Republic of China
	Funding: The National Nature Science Foundation of China (contract number: 10875146) The bucket ion source is widely used as the high energy beam source on the high power neutral beam injector system. A hot cathode bucket ion source is studied for the diagnostic neutral beam injector. The main parameters which influence the performance of bucket ion source are arc voltage, filament voltage, gas inlet rate and extracted voltage. In the experiment, only one parameter setting is varied when other parameter settings are fixed. The characteristics of ion source are got and the parameters setting valve are as follows: four filaments current from 500 A to 550 A, arc voltage from 120 V to 200 V, and ion source pressure during discharge is from 2.0 mTorr to 4.5 mTorr, extracted voltage from 40kV to 50kV. The arc current is higher than 100 A, and extracted beam current can reaches 6 A. Based on this, the arc efficiency, beam power deposition and beam proton ratio of ion source are analyzed and optimized. The proton ratio of extracted beam increased from 28 % to 40 %. It is very useful for the experimental operation and study about the bucket ion source.

MOPCP049	Ion Source Related Research Work at JYFL	ion, ion-source, plasma, resonance	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.

TUA1CIO01	A Multi MegaWatt Cyclotron Complex to Search for CP Violation in the Neutrino Sector	cyclotron, extraction, proton, injection	298
	L. Calabretta, M.M. Maggiore, L.A.C. Piazza, D. Rifuggiato INFN/LNS, Catania, Italy
	Funding: I.N.F.N., Laboratorio Nazionale del Sud, Catania, Italy Scientists of Massachusetts Institute of Technology (MIT) proposed a new approach to search for CP violation in the neutrino sector . They proposed to use high-power proton accelerators able to deliver a proton beam whit energy 800 MeV, 1.5 MW power and duty cycle of 20% (100 μs beam on, 400 μs beam off). In the past, a layout for a similar accelerator complex to get a proton beam with 10MW of power was proposed by the LNS Accelerator Team . This previous machines' proposal is now updated to meet the MIT requirements. It consists in a two cascade cyclotron complex. The injector cyclotron, is a four sector machine, which accelerates a beam of H²⁺ up to energy of 35 MeV/n. The extraction radius is set around 130 cm and the energy gain is fixed at 1.1 MeV/turn, to obtain a turn separation of about 11 mm and then to make very efficient the extraction by the electrostatic deflector. The beam is then injected inside a 8 sectors Superconducting Cyclotron Ring. The energy gain is set at about 3 MeV/turn to reduce the number of turns inside the Ring cyclotron. The beam is extracted by the stripper method. The main characteristics and features of the machines will be presented. J. M. Conrad and M. H. Shaevitz, "Multiple Cyclotron Method to Search for CP violation in the Neutrino Sector", Phys. Rev.Lett. 104:141802, 2010 ** L. Calabretta et Al., EPAC(2000),pp.918
	Slides TUA1CIO01 [2.341 MB]

WEM1CIO03	New Tools for the Improvement of Beam Brightness in ECR Ion Sources	plasma, ion, resonance, 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.

THM1CIO04	Progress towards New RI and Higher RIB Intensities at TRIUMF	target, ion, ion-source, proton	365
	P.G. Bricault, F. Ames, M. Dombsky, V. Hanemaayer, P. Kunz, J. Lassen TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada
	Funding: TRIUMF is owned and operated as a joint venture by a consortium of Canadian Universities via a contribution through the National Research Council of Canada. Over the past five years TRIUMF has operated routinely the ISAC facility at proton beam intensity around and above 70 μA. Contrary to other ISOL facilities ISAC utilizes a modular assembly for the target station. This is mainly to provide enough radiation shielding for operation at high proton beam intensity. So far ISAC was licensed to operate target material Z < 82. Two actinide target (UO2) tests have been performed during the past two years to assess the ISAC systems (vacuum, nuclear ventilation, personnel safety) for actinide operation. The uranium oxide target is limited to 2 μA only because of the low operating temperature. We are now developing a uranium carbide target using similar techniques as for our other carbide targets (SiC, TiC, ZrC) operating up to 70 μA. Among the recent upgrade, the mass range, which was so far limited to mass lower than 30 has been increased to 150 with the installation of a charge state booster.
	Slides THM1CIO04 [5.623 MB]

THM2CCO03	Stripper Foil Developments at NSCL/MSU	ion, cyclotron, light-ion, gun	373
	F. Marti, S. Hitchcock, P.S. Miller, J.W. Stetson, J. Yurkon NSCL, East Lansing, Michigan, USA
	Funding: Work supported by DOE Cooperative Agreement DE-SC0000661 and National Science Foundation under grant No. PHY06-06007 The Coupled Cyclotrons Facility (CCF) at NSCL/MSU includes an injector cyclotron (K500) and a booster cyclotron (K1200). The beam from the K500 is injected radially into the K1200 and stripped at approximately one third of the radius at energies of approximately 10 MeV/u. Stripping is done with a carbon foil. The lifetime of the foil is very short when stripping heavy ions and does not agree with the estimates from formulas that work quite well for light ions. We will present in this paper the studies performed to understand the limitations and improve the lifetime of the foils. A foil test chamber with an electron gun has been built as part of the R&D for the Facility for Rare Isotope Beams (FRIB) project. It has been used to study different ways of supporting the carbon foils and effects of high temperature operation. Different foil materials (diamond-like carbon, graphene, etc) have been tested in the cyclotron.
	Slides THM2CCO03 [4.560 MB]

Paper

Title

Other Keywords

Page

MOM1CIO02

Eighty Years of Cyclotrons

cyclotron, ion, focusing, proton

1

M.K. Craddock
UBC & TRIUMF, Vancouver, British Columbia, Canada

Lawrence's invention of the cyclotron in 1930 not only revolutionized nuclear physics, but proved the starting point for a whole variety of recirculating accelerators, from microtrons to FFAGs to synchrotrons, that have had an enormous impact in almost every branch of science and several areas of medicine and industry. Cyclotrons (i.e. fixed-field accelerators) themselves have proved remarkably adaptable, incorporating a variety of new ideas and technologies over the years: frequency modulation, edge focusing, AG focusing, axial and azimuthal injection, ring geometries, stripping extraction, superconducting magnets and rf… Long may they flourish!

Slides MOM1CIO02 [7.108 MB]

MOA2CIO01

HIRFL-CSR Facility Status and Development

ion, target, extraction, injection

37

Y.J. Yuan, X.H. Cai, D.Q. Gao, Y. He, L.Z. Ma, X. Ma, R.S. Mao, Y.W. Su, X.L. Tu, J.W. Xia, H.S. Xu, Z. Xu, J.C. Yang, X.D. Yang, X.T. Yang, Y.P. Yang, W. Zhang, H.W. Zhao
IMP, Lanzhou, People's Republic of China

The HIRFL-CSR facility come into operation by the end of 2007. During operation in recent years, CSR supplied beam for experiments at several terminals and inside both CSRm and CSRe rings. The experiments covers high resolution mass measurement, cancer therapy research, neutron wall, atomic physics using electron target and internal gas target, using injection beam mainly from the SFC of cyclotron injector. New methods and further developments are required to improve the performance of CSR system including multi-gradients measurement method for beam spot commissioning and beam transfer, nonlinear effect correction and stabilization of isochronous mode of CSRe. For suppling of heverier ion beam with proper ernergy, the cyclotron complex should be enhanced and new injector is proposed to replace SFC as injector of SSC.

Slides MOA2CIO01 [3.766 MB]

MOPCP044

New Magnetic Einzel Lens and Its Beam Optical Features

focusing, optics, ion, controls

141

M.H. Rashid, R.K. Bhandari, C. Mallik
DAE/VECC, Calcutta, India

Magnetic cylindrical lens is used mostly in beam lines to focus and transport low energy beam. It is well known that focusing power of a magnetic solenoid lens depends on the ratio of particle momentum and electric charge. A solenoid rotates also an ion beam while focusing it and the phase space areas of the beam in x- and y-plane get entangled and increased. The paper reported here describes an effort to design a new magnetic Einzel lens using a pair of Glaser lens in anti-solenoid mode for the first time to get zero rotation of the exit beam. Analytical formulae have been generated to deduce the scalar magnetic potential and field along the central axis of the lens. Thereafter, beam optics and particle tracking is done using the combined field of a pair of Glaser Lenses constituting the magnetic Einzel lens. The required focusing power of the designed lens is achieved for a beam of given rigidity.

MOPCP047

Analysis of Beam Quality Optimization of Bucket Ion Source

ion, ion-source, proton, plasma

147

Y.H. Xie, C.D. Hu, C.C. Jiang, L.Z. Liang, S. Liu, Y.L. Xie
ASIPP, Hefei, People's Republic of China

Funding: The National Nature Science Foundation of China (contract number: 10875146)
The bucket ion source is widely used as the high energy beam source on the high power neutral beam injector system. A hot cathode bucket ion source is studied for the diagnostic neutral beam injector. The main parameters which influence the performance of bucket ion source are arc voltage, filament voltage, gas inlet rate and extracted voltage. In the experiment, only one parameter setting is varied when other parameter settings are fixed. The characteristics of ion source are got and the parameters setting valve are as follows: four filaments current from 500 A to 550 A, arc voltage from 120 V to 200 V, and ion source pressure during discharge is from 2.0 mTorr to 4.5 mTorr, extracted voltage from 40kV to 50kV. The arc current is higher than 100 A, and extracted beam current can reaches 6 A. Based on this, the arc efficiency, beam power deposition and beam proton ratio of ion source are analyzed and optimized. The proton ratio of extracted beam increased from 28 % to 40 %. It is very useful for the experimental operation and study about the bucket ion source.

MOPCP049

Ion Source Related Research Work at JYFL

ion, ion-source, plasma, resonance

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.

TUA1CIO01

A Multi MegaWatt Cyclotron Complex to Search for CP Violation in the Neutrino Sector

cyclotron, extraction, proton, injection

298

L. Calabretta, M.M. Maggiore, L.A.C. Piazza, D. Rifuggiato
INFN/LNS, Catania, Italy

Funding: I.N.F.N., Laboratorio Nazionale del Sud, Catania, Italy
Scientists of Massachusetts Institute of Technology (MIT) proposed a new approach to search for CP violation in the neutrino sector *. They proposed to use high-power proton accelerators able to deliver a proton beam whit energy 800 MeV, 1.5 MW power and duty cycle of 20% (100 μs beam on, 400 μs beam off). In the past, a layout for a similar accelerator complex to get a proton beam with 10MW of power was proposed by the LNS Accelerator Team **. This previous machines' proposal is now updated to meet the MIT requirements. It consists in a two cascade cyclotron complex. The injector cyclotron, is a four sector machine, which accelerates a beam of H²⁺ up to energy of 35 MeV/n. The extraction radius is set around 130 cm and the energy gain is fixed at 1.1 MeV/turn, to obtain a turn separation of about 11 mm and then to make very efficient the extraction by the electrostatic deflector. The beam is then injected inside a 8 sectors Superconducting Cyclotron Ring. The energy gain is set at about 3 MeV/turn to reduce the number of turns inside the Ring cyclotron. The beam is extracted by the stripper method. The main characteristics and features of the machines will be presented.
* J. M. Conrad and M. H. Shaevitz, "Multiple Cyclotron Method to Search for CP violation in the Neutrino Sector", Phys. Rev.Lett. 104:141802, 2010
** L. Calabretta et Al., EPAC(2000),pp.918

Slides TUA1CIO01 [2.341 MB]

WEM1CIO03

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

plasma, ion, resonance, 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.

THM1CIO04

Progress towards New RI and Higher RIB Intensities at TRIUMF

target, ion, ion-source, proton

365

P.G. Bricault, F. Ames, M. Dombsky, V. Hanemaayer, P. Kunz, J. Lassen
TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada

Funding: TRIUMF is owned and operated as a joint venture by a consortium of Canadian Universities via a contribution through the National Research Council of Canada.
Over the past five years TRIUMF has operated routinely the ISAC facility at proton beam intensity around and above 70 μA. Contrary to other ISOL facilities ISAC utilizes a modular assembly for the target station. This is mainly to provide enough radiation shielding for operation at high proton beam intensity. So far ISAC was licensed to operate target material Z < 82. Two actinide target (UO2) tests have been performed during the past two years to assess the ISAC systems (vacuum, nuclear ventilation, personnel safety) for actinide operation. The uranium oxide target is limited to 2 μA only because of the low operating temperature. We are now developing a uranium carbide target using similar techniques as for our other carbide targets (SiC, TiC, ZrC) operating up to 70 μA. Among the recent upgrade, the mass range, which was so far limited to mass lower than 30 has been increased to 150 with the installation of a charge state booster.

Slides THM1CIO04 [5.623 MB]

THM2CCO03

Stripper Foil Developments at NSCL/MSU

ion, cyclotron, light-ion, gun

373

F. Marti, S. Hitchcock, P.S. Miller, J.W. Stetson, J. Yurkon
NSCL, East Lansing, Michigan, USA

Funding: Work supported by DOE Cooperative Agreement DE-SC0000661 and National Science Foundation under grant No. PHY06-06007
The Coupled Cyclotrons Facility (CCF) at NSCL/MSU includes an injector cyclotron (K500) and a booster cyclotron (K1200). The beam from the K500 is injected radially into the K1200 and stripped at approximately one third of the radius at energies of approximately 10 MeV/u. Stripping is done with a carbon foil. The lifetime of the foil is very short when stripping heavy ions and does not agree with the estimates from formulas that work quite well for light ions. We will present in this paper the studies performed to understand the limitations and improve the lifetime of the foils. A foil test chamber with an electron gun has been built as part of the R&D for the Facility for Rare Isotope Beams (FRIB) project. It has been used to study different ways of supporting the carbon foils and effects of high temperature operation. Different foil materials (diamond-like carbon, graphene, etc) have been tested in the cyclotron.

Slides THM2CCO03 [4.560 MB]