ECRIS-2014 - List of Keywords (ECRIS)

Paper	Title	Other Keywords	Page
MOOBMH01	Periodic Beam Burrent Oscillations Driven By Electron Cyclotron Instabilities In ECRIS Plasmas	plasma, electron, ion, cyclotron	5
	O.A. Tarvainen, T. Kalvas, H. A. Koivisto, J.P.O. Komppula, R.J. Kronholm, J.P. Laulainen JYFL, Jyväskylä, Finland I. Izotov, D. Mansfeld, V. Skalyga IAP/RAS, Nizhny Novgorod, Russia V. Toivanen CERN, Geneva, Switzerland
	Experimental observation of cyclotron instabilities in electron cyclotron resonance ion source plasma operated in cw-mode is reported. The instabilities are associated with strong microwave emission and a burst of energetic electrons escaping the plasma, and explain the periodic oscillations of the extracted beam currents. The instabilities are shown to restrict the parameter space available for the optimization of high charge state ion currents.
	Slides MOOBMH01 [2.020 MB]

MOOAMH03	Optimization Of Low-Energy Beam Transport	emittance, ion, solenoid, dipole	33
	H.R. Kremers, J.P.M. Beijers, S. Brandenburg KVI, Groningen, The Netherlands
	We have studied the extraction and transport of a low-energy ion beam between an Electron Cyclotron Resonance (ECR) Ion Source and the analyzing magnet. This first part of the transport line is particularly sensitive to emittance blowup caused by ion-optical aberrations and non-paraxiality of the beam. This can be prevented by an appropriate focussing element between ion source and analyzing magnet. We present the results of beam transport simulations for different focussing elements including an einzel lens, solenoid and quadrupole element. These calculations, verified by measurements, lead to a design of an optimal, low-energy beam transport line for ion beams with large beam divergences.
	Slides MOOAMH03 [2.910 MB]

MOPPH007	Current Developments for Increasing the Beam Intensities of the RIKEN 18-GHz Superconductiong ECR Ion Source	ion, emittance, ion-source, cyclotron	57
	T. Nagatomo, V. Tzoganis RIKEN, Saitama, Japan O. Kamigaito, M. Kase, Y. Kotaka, T. Nakagawa RIKEN Nishina Center, Wako, Japan Y. Kotaka SHI Accelerator Service Ltd., Tokyo, Japan Y. Ohshiro CNS, Saitama, Japan V. Tzoganis The University of Liverpool, Liverpool, United Kingdom
	Providing intense and highly charged heavy ion beams is one of the most essential and fundamental technologies to explore a trackless frontier so-called “Island of Stability” where relatively stable super heavy elements are considered to exist. Towards this goal, the development of an ion source that can provide a highly charged heavy ion beam with high intensity and low emittance is necessary. In order to provide the desired high intensity ion beam, the beam-radius expansion induced by space charge effects cannot be ignored, and it can cause considerable degradation of the beam emittance. To suppress such effects at the output of an ion source is one of the top priorities in the direction of improving both the quality and intensity of the beam. At first, we plan to examine the space charge effects with a high-intensity beam provided by the 18-GHz Superconducting ECR Ion Source at RIKEN Nishina Center. To measure the degradation of the beam emittance as function of the beam’s intensity, an in-situ emittance monitor system based on the pepperpot technique and applicable to a wide range of beam intensities is being developed. A report on the current status will be presented.

TUOMMH01	Improvement of Beam Intensities for Ion Beams with Charge-to-Mass Ratio of 1/3 with Two-Frequency Heating Technique	ion, extraction, experiment, plasma	83
	A. Kitagawa NIRS, Chiba-shi, Japan T.F. Fujita, M. Muramatsu National Institute of Radiological Sciences, Chiba, Japan K. Fukushima, N. Sasaki, K. Takahashi, W. Takasugi AEC, Chiba, Japan Y. Kato Osaka University, Graduate School of Engineering, Osaka, Japan
	Facilities of heavy ion radiotherapy use carbon ions due to its better biological dose distributions. The necessary energy is over 400MeV/u. A typical accelerator system consisits of a synchrotron and an injector. ECR ion sources have been developed and utilized to produce C⁴⁺ ions. On the other hand, in order to study basic biological researches with a such facility, there are occasionally requirements to produce other ion species like Ar or Fe. Since the injector design is fixed for the acceleration of ions with a charge-to-mass ratio of about 1/3, the ion source must produce Ar¹³⁺ and Fe¹⁹⁺. As a method to improve highly-charged ion production, the technique to feed multiple microwaves with different frequencies is well-known. Our group studied the improvements when the two frequencies are close together each with a power of more than 1kW using the 18GHz NIRS-HEC ECR ion source installed in the Heavy Ion Medical Accelerator in Chiba (HIMAC. Fe and Ni are interesting for a risk study in space environment. We combined the MIVOC method and the two-frequency heating technique for the production of Fe and Ni. The recent test results will be reported.
	Slides TUOMMH01 [2.651 MB]

WEOMMH04	Thermal Design of Refridgerated Hexapole 18 GHz ECRIS HIISI	plasma, electron, simulation, permanent-magnet	114
	T. Kalvas, H. A. Koivisto, K. Ranttila, O.A. Tarvainen JYFL, Jyväskylä, Finland
	A project is underway for constructing a new 18 GHz ECR ion source HIISI at University of Jyväskylä. An innovative plasma chamber structure with grooves at magnetic poles is being studied. This allows large chamber radius at the poles, which is relevant for the performance of the ion source while smaller radius between the poles makes space for chamber water cooling. The hexapole will be refridgerated to sub-zero temperatures to boost the coercivity and the remanence of the permanent magnet material. The hexapole structure is insulated from high temperature solenoid coils and plasma chamber by vacuum. The thermal design of the structure has been made using a thermal diffusion code taking in account radiative, conductive and convective heat transfer processes. The heat flux from plasma has been estimated using electron trajectory simulations with sensitivity analysis on the electron energy distribution. The electron simulations are verified by comparing to experimental data from 14 GHz ECR. The electron and thermodynamic simulation efforts are presented together with an analysis of the H-field vs. coersivity in the permanent magnets.
	Slides WEOMMH04 [5.163 MB]

WEOBMH01	Experimental Activities with the LPSC Charge Breeder in the European Context	ion, plasma, injection, ECR	120
	T. Lamy, J. Angot, T. Thuillier LPSC, Grenoble Cedex, France J. Choinski, L. Standylo HIL, Warsaw, Poland P. Delahaye, L. Maunoury GANIL, Caen, France A. Galatà INFN/LNL, Legnaro (PD), Italy H. A. Koivisto, O.A. Tarvainen JYFL, Jyväskylä, Finland G. Patti INFN/LNS, Catania, Italy
	Funding: NuPNET project (Enhanced Multi-Ionization of short-Lived Isotopes at EURISOL) One of the Work Packages of the "Enhanced Multi-Ionization of short-Lived Isotopes at EURISOL" NuPNET project focuses on the ECR charge breeding. The LPSC charge breeder is used for experimental studies in order to better understand the fundamental processes involved in the 1+ beam capture by a 14 GHz ECR plasma. Some improvements, like symmetrisation of the magnetic field at the injection side and higher pumping speed, have been carried out on the PHOENIX charge breeder. The impact of these modifications on the efficiencies and charge breeding times are presented. In the same time, the new LPSC 1+ source developments performed in order to ease the efficiency measurements with various elements are presented.
	Slides WEOBMH01 [4.982 MB]

THOBMH01	Closing Remarks for ECRIS'14	ion, ECR, ion-source, plasma	144
	T. Thuillier LPSC, Grenoble Cedex, France
	A scientific overview of the ECRIS14 workshop is proposed in this paper. The workshop content demonstrated that the ECR community is still very active and that research is of high interest for future accelerator projects. A selection of new results and development presented during the workshop is proposed.

Paper

Title

Other Keywords

Page

MOOBMH01

Periodic Beam Burrent Oscillations Driven By Electron Cyclotron Instabilities In ECRIS Plasmas

plasma, electron, ion, cyclotron

5

O.A. Tarvainen, T. Kalvas, H. A. Koivisto, J.P.O. Komppula, R.J. Kronholm, J.P. Laulainen
JYFL, Jyväskylä, Finland
I. Izotov, D. Mansfeld, V. Skalyga
IAP/RAS, Nizhny Novgorod, Russia
V. Toivanen
CERN, Geneva, Switzerland

Experimental observation of cyclotron instabilities in electron cyclotron resonance ion source plasma operated in cw-mode is reported. The instabilities are associated with strong microwave emission and a burst of energetic electrons escaping the plasma, and explain the periodic oscillations of the extracted beam currents. The instabilities are shown to restrict the parameter space available for the optimization of high charge state ion currents.

Slides MOOBMH01 [2.020 MB]

MOOAMH03

Optimization Of Low-Energy Beam Transport

emittance, ion, solenoid, dipole

33

H.R. Kremers, J.P.M. Beijers, S. Brandenburg
KVI, Groningen, The Netherlands

We have studied the extraction and transport of a low-energy ion beam between an Electron Cyclotron Resonance (ECR) Ion Source and the analyzing magnet. This first part of the transport line is particularly sensitive to emittance blowup caused by ion-optical aberrations and non-paraxiality of the beam. This can be prevented by an appropriate focussing element between ion source and analyzing magnet. We present the results of beam transport simulations for different focussing elements including an einzel lens, solenoid and quadrupole element. These calculations, verified by measurements, lead to a design of an optimal, low-energy beam transport line for ion beams with large beam divergences.

Slides MOOAMH03 [2.910 MB]

MOPPH007

Current Developments for Increasing the Beam Intensities of the RIKEN 18-GHz Superconductiong ECR Ion Source

ion, emittance, ion-source, cyclotron

57

T. Nagatomo, V. Tzoganis
RIKEN, Saitama, Japan
O. Kamigaito, M. Kase, Y. Kotaka, T. Nakagawa
RIKEN Nishina Center, Wako, Japan
Y. Kotaka
SHI Accelerator Service Ltd., Tokyo, Japan
Y. Ohshiro
CNS, Saitama, Japan
V. Tzoganis
The University of Liverpool, Liverpool, United Kingdom

Providing intense and highly charged heavy ion beams is one of the most essential and fundamental technologies to explore a trackless frontier so-called “Island of Stability” where relatively stable super heavy elements are considered to exist. Towards this goal, the development of an ion source that can provide a highly charged heavy ion beam with high intensity and low emittance is necessary. In order to provide the desired high intensity ion beam, the beam-radius expansion induced by space charge effects cannot be ignored, and it can cause considerable degradation of the beam emittance. To suppress such effects at the output of an ion source is one of the top priorities in the direction of improving both the quality and intensity of the beam. At first, we plan to examine the space charge effects with a high-intensity beam provided by the 18-GHz Superconducting ECR Ion Source at RIKEN Nishina Center. To measure the degradation of the beam emittance as function of the beam’s intensity, an in-situ emittance monitor system based on the pepperpot technique and applicable to a wide range of beam intensities is being developed. A report on the current status will be presented.

TUOMMH01

Improvement of Beam Intensities for Ion Beams with Charge-to-Mass Ratio of 1/3 with Two-Frequency Heating Technique

ion, extraction, experiment, plasma

83

A. Kitagawa
NIRS, Chiba-shi, Japan
T.F. Fujita, M. Muramatsu
National Institute of Radiological Sciences, Chiba, Japan
K. Fukushima, N. Sasaki, K. Takahashi, W. Takasugi
AEC, Chiba, Japan
Y. Kato
Osaka University, Graduate School of Engineering, Osaka, Japan

Facilities of heavy ion radiotherapy use carbon ions due to its better biological dose distributions. The necessary energy is over 400MeV/u. A typical accelerator system consisits of a synchrotron and an injector. ECR ion sources have been developed and utilized to produce C⁴⁺ ions. On the other hand, in order to study basic biological researches with a such facility, there are occasionally requirements to produce other ion species like Ar or Fe. Since the injector design is fixed for the acceleration of ions with a charge-to-mass ratio of about 1/3, the ion source must produce Ar¹³⁺ and Fe¹⁹⁺. As a method to improve highly-charged ion production, the technique to feed multiple microwaves with different frequencies is well-known. Our group studied the improvements when the two frequencies are close together each with a power of more than 1kW using the 18GHz NIRS-HEC ECR ion source installed in the Heavy Ion Medical Accelerator in Chiba (HIMAC. Fe and Ni are interesting for a risk study in space environment. We combined the MIVOC method and the two-frequency heating technique for the production of Fe and Ni. The recent test results will be reported.

Slides TUOMMH01 [2.651 MB]

WEOMMH04

Thermal Design of Refridgerated Hexapole 18 GHz ECRIS HIISI

plasma, electron, simulation, permanent-magnet

114

T. Kalvas, H. A. Koivisto, K. Ranttila, O.A. Tarvainen
JYFL, Jyväskylä, Finland

A project is underway for constructing a new 18 GHz ECR ion source HIISI at University of Jyväskylä. An innovative plasma chamber structure with grooves at magnetic poles is being studied. This allows large chamber radius at the poles, which is relevant for the performance of the ion source while smaller radius between the poles makes space for chamber water cooling. The hexapole will be refridgerated to sub-zero temperatures to boost the coercivity and the remanence of the permanent magnet material. The hexapole structure is insulated from high temperature solenoid coils and plasma chamber by vacuum. The thermal design of the structure has been made using a thermal diffusion code taking in account radiative, conductive and convective heat transfer processes. The heat flux from plasma has been estimated using electron trajectory simulations with sensitivity analysis on the electron energy distribution. The electron simulations are verified by comparing to experimental data from 14 GHz ECR. The electron and thermodynamic simulation efforts are presented together with an analysis of the H-field vs. coersivity in the permanent magnets.

Slides WEOMMH04 [5.163 MB]

WEOBMH01

Experimental Activities with the LPSC Charge Breeder in the European Context

ion, plasma, injection, ECR

120

T. Lamy, J. Angot, T. Thuillier
LPSC, Grenoble Cedex, France
J. Choinski, L. Standylo
HIL, Warsaw, Poland
P. Delahaye, L. Maunoury
GANIL, Caen, France
A. Galatà
INFN/LNL, Legnaro (PD), Italy
H. A. Koivisto, O.A. Tarvainen
JYFL, Jyväskylä, Finland
G. Patti
INFN/LNS, Catania, Italy

Funding: NuPNET project (Enhanced Multi-Ionization of short-Lived Isotopes at EURISOL)
One of the Work Packages of the "Enhanced Multi-Ionization of short-Lived Isotopes at EURISOL" NuPNET project focuses on the ECR charge breeding. The LPSC charge breeder is used for experimental studies in order to better understand the fundamental processes involved in the 1+ beam capture by a 14 GHz ECR plasma. Some improvements, like symmetrisation of the magnetic field at the injection side and higher pumping speed, have been carried out on the PHOENIX charge breeder. The impact of these modifications on the efficiencies and charge breeding times are presented. In the same time, the new LPSC 1+ source developments performed in order to ease the efficiency measurements with various elements are presented.

Slides WEOBMH01 [4.982 MB]

THOBMH01

Closing Remarks for ECRIS'14

ion, ECR, ion-source, plasma

144

T. Thuillier
LPSC, Grenoble Cedex, France

A scientific overview of the ECRIS14 workshop is proposed in this paper. The workshop content demonstrated that the ECR community is still very active and that research is of high interest for future accelerator projects. A selection of new results and development presented during the workshop is proposed.