ECRIS2010 - List of Authors (Ropponen, T.)

Paper

Title

Page

Time Evolution of Plasma Potential in Pulsed Operation of ECRIS

93

O.A. Tarvainen, H. A. Koivisto, T. Ropponen, V.A. Toivanen
JYFL, Jyväskylä, Finland
Y. Higurashi, T. Nakagawa
RIKEN Nishina Center, Wako, Japan

The time evolution of plasma potential has been measured in pulsed operation mode with electron cyclotron resonance ion sources at JYFL and RIKEN. Three different ion sources with microwave frequencies ranging from 6.4 to 18 GHz were employed for the experiments. The plasma potential during the preglow and afterglow transients was compared with steady state conditions. The plasma potential was observed to increase 25-75 % during the preglow and 10-30 % during the afterglow. We describe the experimental procedure and present the results of the study in detail.

Slides TUCOBK03 [0.973 MB]

MOCOAK02

Intense Beam Production with SuSI

4

L.T. Sun, J. Brandon, D.G. Cole, M. Doleans, G. Machicoane, D. Morris, T. Ropponen, L. Tobos
NSCL, East Lansing, Michigan, USA
E. Pozdeyev
FRIB, East Lansing, Michigan, USA

SuSI ion source, a 3rd generation fully superconducting ECR ion source is now used for injection into the Coupled Cyclotron Facility since September 2009. Initial performances during the commissioning of SuSI were mainly limited by the microwave power available from a single 18 GHz microwave amplifier, especially for the production of heavier ion beams. The Injection of SuSI was modified to add a second 18 GHz amplifier, to reach a maximum of 3.0 kW of RF power inside the plasma chamber. Production of heavy ion beams, such as Kr¹⁴⁺, Bi³⁰⁺ and U³³⁺ is reported, to demonstrate the performance of SuSI. Additional studies were made with various ion source parameters to optimize the beam intensity within a normalized emittance of 0.9pi.mm.mrad as needed for the FRIB project and will be reported in this paper.

Slides MOCOAK02 [1.672 MB]

MOCOBK01

ECR Ion Sources for the Facility for Rare Isotope Beams (FRIB) Project at Michigan State University

14

G. Machicoane, M. Doleans, O.K. Kester, T. Ropponen, L.T. Sun, X. Wu
NSCL, East Lansing, Michigan, USA
D. Leitner
LBNL, Berkeley, California, USA
E. Pozdeyev, E. Tanke
FRIB, East Lansing, Michigan, USA

Funding: Work supported by US DOE Cooperative Agreement DE-SC0000661
Once operational, the Facility for Rare Isotope Beams (FRIB) will open the possibility to gain key understanding in nuclear science and in particular regarding the properties of nuclei far from the valley of stability or the nuclear processes in the universe. In addition it will also allow experimenters to test fundamental symmetries. The production of rare isotopes with FRIB will be achieved, using a heavy ion driver linac that will accelerate a stable isotope beam to 200 MeV/u and deliver it on a fragmentation target. FRIB aims to reach a primary beam power of 400 kW for light to heavy elements up to Uranium. To meet the intensity requirement two high performance ECR ion sources operating at 28 GHz will be used to produce high intensity of medium to high charge state ion beams. Plans regarding initial beam production with the ECR ion sources and beam transport through the front end will be discussed.

Slides MOCOBK01 [3.259 MB]

MOPOT016

A Low Power Survey of Radial-Offset Axial Sputtering and High Intensity Uranium Production from Axial Sputtering in SuSI

69

D.G. Cole, G. Machicoane, T. Ropponen, L.T. Sun, L. Tobos
NSCL, East Lansing, Michigan, USA

Prototype sputtering hardware has been tested in the SuSI ion source and early uranium ion production is discussed. Also, results of a low power survey of axial sputtering, to test sputtering efficiency at incremental radial offsets from on axis position, is reported.

Poster MOPOT016 [2.672 MB]

WECOAK04

Bremsstrahlung and Ion Beam Current Measurements With SuSI ECR Ion Source

171

T. Ropponen, D.G. Cole, G. Machicoane, A. Stolz, L.T. Sun, L. Tobos
NSCL, East Lansing, Michigan, USA

The Superconducting Source for Ions (SuSI) at the National Superconducting Cyclotron Laboratory at Michigan State University is a fully superconducting 3rd generation ECR ion source. The axial magnetic field is generated by six solenoid magnets which allow to control the magnetic field characteristics, such as resonance locations, mirror ratios and magnetic field gradients, almost independently. In addition, a collimation scheme in the SuSI beam line after the analyzing magnet has been developed to optimize the ion beam production from the ion source within a given acceptance. These aspects make SuSI an excellent tool for ECRIS research and development. In this paper we will focus on the bremsstrahlung and ion beam current measurements where the gradient on the magnetic field is changed while keeping the Bmin and axial plasma length as constants. We will also show how the shift of the extraction side resonance location affects the extracted ion beam currents and radiation spectra and, finally, we will discuss about the effect of flatB mode with a modern superconducting ECR ion source on the ion beam production and radiation levels.

Slides WECOAK04 [3.752 MB]

TUPOT010

Effects of Microwave Frequency Fine Tuning on the Performance of JYFL 14 GHz ECRIS

137

V.A. Toivanen, V.P. Aho, J. Ärje, P. Jones, J.A. Kauppinen, H. A. Koivisto, P. Peura, O.A. Tarvainen
JYFL, Jyväskylä, Finland
L. Celona, G. Ciavola, S. Gammino
INFN/LNS, Catania, Italy
A. Galatà
INFN/LNL, Legnaro (PD), Italy
D. Mascali
CSFNSM, Catania, Italy
T. Ropponen
NSCL, East Lansing, Michigan, USA

Measurements have been carried out at Department of Physics, University of Jyväskylä (JYFL) to study the effects of microwave frequency fine tuning on the performance of JYFL 14 GHz electron cyclotron resonance ion source. The frequency was varied within an 85 MHz band around the normal operation frequency of 14.085 GHz. The radial bremsstrahlung emission was measured for plasma diagnostics purposes and mass separated ion beam currents extracted from the ion source were recorded at the same time. Also, beam quality studies were conducted by measuring the ion beam emittance and shape with and without enhanced space charge compensation. The obtained results are presented and possible origins of seen phenomena in measured quantities are discussed.

Poster TUPOT010 [0.678 MB]

Paper	Title	Page
TUCOBK03	Time Evolution of Plasma Potential in Pulsed Operation of ECRIS	93
	O.A. Tarvainen, H. A. Koivisto, T. Ropponen, V.A. Toivanen JYFL, Jyväskylä, Finland Y. Higurashi, T. Nakagawa RIKEN Nishina Center, Wako, Japan
	The time evolution of plasma potential has been measured in pulsed operation mode with electron cyclotron resonance ion sources at JYFL and RIKEN. Three different ion sources with microwave frequencies ranging from 6.4 to 18 GHz were employed for the experiments. The plasma potential during the preglow and afterglow transients was compared with steady state conditions. The plasma potential was observed to increase 25-75 % during the preglow and 10-30 % during the afterglow. We describe the experimental procedure and present the results of the study in detail.
	Slides TUCOBK03 [0.973 MB]

MOCOAK02	Intense Beam Production with SuSI	4
	L.T. Sun, J. Brandon, D.G. Cole, M. Doleans, G. Machicoane, D. Morris, T. Ropponen, L. Tobos NSCL, East Lansing, Michigan, USA E. Pozdeyev FRIB, East Lansing, Michigan, USA
	SuSI ion source, a 3rd generation fully superconducting ECR ion source is now used for injection into the Coupled Cyclotron Facility since September 2009. Initial performances during the commissioning of SuSI were mainly limited by the microwave power available from a single 18 GHz microwave amplifier, especially for the production of heavier ion beams. The Injection of SuSI was modified to add a second 18 GHz amplifier, to reach a maximum of 3.0 kW of RF power inside the plasma chamber. Production of heavy ion beams, such as Kr¹⁴⁺, Bi³⁰⁺ and U³³⁺ is reported, to demonstrate the performance of SuSI. Additional studies were made with various ion source parameters to optimize the beam intensity within a normalized emittance of 0.9pi.mm.mrad as needed for the FRIB project and will be reported in this paper.
	Slides MOCOAK02 [1.672 MB]

MOCOBK01	ECR Ion Sources for the Facility for Rare Isotope Beams (FRIB) Project at Michigan State University	14
	G. Machicoane, M. Doleans, O.K. Kester, T. Ropponen, L.T. Sun, X. Wu NSCL, East Lansing, Michigan, USA D. Leitner LBNL, Berkeley, California, USA E. Pozdeyev, E. Tanke FRIB, East Lansing, Michigan, USA
	Funding: Work supported by US DOE Cooperative Agreement DE-SC0000661 Once operational, the Facility for Rare Isotope Beams (FRIB) will open the possibility to gain key understanding in nuclear science and in particular regarding the properties of nuclei far from the valley of stability or the nuclear processes in the universe. In addition it will also allow experimenters to test fundamental symmetries. The production of rare isotopes with FRIB will be achieved, using a heavy ion driver linac that will accelerate a stable isotope beam to 200 MeV/u and deliver it on a fragmentation target. FRIB aims to reach a primary beam power of 400 kW for light to heavy elements up to Uranium. To meet the intensity requirement two high performance ECR ion sources operating at 28 GHz will be used to produce high intensity of medium to high charge state ion beams. Plans regarding initial beam production with the ECR ion sources and beam transport through the front end will be discussed.
	Slides MOCOBK01 [3.259 MB]

MOPOT016	A Low Power Survey of Radial-Offset Axial Sputtering and High Intensity Uranium Production from Axial Sputtering in SuSI	69
	D.G. Cole, G. Machicoane, T. Ropponen, L.T. Sun, L. Tobos NSCL, East Lansing, Michigan, USA
	Prototype sputtering hardware has been tested in the SuSI ion source and early uranium ion production is discussed. Also, results of a low power survey of axial sputtering, to test sputtering efficiency at incremental radial offsets from on axis position, is reported.
	Poster MOPOT016 [2.672 MB]

WECOAK04	Bremsstrahlung and Ion Beam Current Measurements With SuSI ECR Ion Source	171
	T. Ropponen, D.G. Cole, G. Machicoane, A. Stolz, L.T. Sun, L. Tobos NSCL, East Lansing, Michigan, USA
	The Superconducting Source for Ions (SuSI) at the National Superconducting Cyclotron Laboratory at Michigan State University is a fully superconducting 3rd generation ECR ion source. The axial magnetic field is generated by six solenoid magnets which allow to control the magnetic field characteristics, such as resonance locations, mirror ratios and magnetic field gradients, almost independently. In addition, a collimation scheme in the SuSI beam line after the analyzing magnet has been developed to optimize the ion beam production from the ion source within a given acceptance. These aspects make SuSI an excellent tool for ECRIS research and development. In this paper we will focus on the bremsstrahlung and ion beam current measurements where the gradient on the magnetic field is changed while keeping the Bmin and axial plasma length as constants. We will also show how the shift of the extraction side resonance location affects the extracted ion beam currents and radiation spectra and, finally, we will discuss about the effect of flatB mode with a modern superconducting ECR ion source on the ion beam production and radiation levels.
	Slides WECOAK04 [3.752 MB]

TUPOT010	Effects of Microwave Frequency Fine Tuning on the Performance of JYFL 14 GHz ECRIS	137
	V.A. Toivanen, V.P. Aho, J. Ärje, P. Jones, J.A. Kauppinen, H. A. Koivisto, P. Peura, O.A. Tarvainen JYFL, Jyväskylä, Finland L. Celona, G. Ciavola, S. Gammino INFN/LNS, Catania, Italy A. Galatà INFN/LNL, Legnaro (PD), Italy D. Mascali CSFNSM, Catania, Italy T. Ropponen NSCL, East Lansing, Michigan, USA
	Measurements have been carried out at Department of Physics, University of Jyväskylä (JYFL) to study the effects of microwave frequency fine tuning on the performance of JYFL 14 GHz electron cyclotron resonance ion source. The frequency was varied within an 85 MHz band around the normal operation frequency of 14.085 GHz. The radial bremsstrahlung emission was measured for plasma diagnostics purposes and mass separated ion beam currents extracted from the ion source were recorded at the same time. Also, beam quality studies were conducted by measuring the ion beam emittance and shape with and without enhanced space charge compensation. The obtained results are presented and possible origins of seen phenomena in measured quantities are discussed.
	Poster TUPOT010 [0.678 MB]