ECRIS2010 - List of Authors (Sortais, P.)

Paper

Title

Page

Ionization Efficiency of a COMIC Ion Source Equipped With a Quartz Plasma Chamber

51

P. Suominen, T. Stora
CERN, Geneva, Switzerland
J. Médard, P. Sortais
LPSC, Grenoble, France

The ISOLDE facility at CERN produces a wide range of radioactive ion beams due to a long history on target and ion source development. Because the radioactive isotope production is very limited, the most important ion source parameters are high ionization efficiency, selectivity and reliable operation under intense radiation. Currently used ion sources (mainly laser (RILIS [1]) and arc discharge -type ion sources (VADIS [2]) do not efficiently ionize light noble gases, such as helium, and molecules, such as CO, N₂ and NO. These beams were previously planned to be produced with 1+ ECR ion sources operating at 2.45 GHz (for example MINIMONO [3]) but due to new and more efficient RF coupling of COMIC-type ion sources [4], we expect to advance in 2.45 GHz ECRIS utilization for radioactive beam production. The new COMIC source designed by LPSC, Grenoble incorporates special features such as a plasma chamber fully made of quartz (Q-COMIC). This should provide chemically good conditions for molecular ion beam production, especially for carbon. This paper presents the first ionization efficiency measurements of the Q-COMIC.
[1] V.N. Fedosseev, et al, Nucl. Instrum. Methods Phys. Res. B 266/19-20 (2008) 4378.
[2] PhD thesis, univ. polyt. Bucarest, L. Penescu (2009).
[3] F. Wenander, W. Farabolini, G. Gaubert, P. Jardin, J. Lettry, Nucl. Phys. A, 746 (2004) 659.
[4] P. Sortais, T. Lamy, J. Médard, J. Angot, L. Latrasse, and T. Thuillier, Rev. Sci. Instrum. 81 (2010) 02B314.

Poster MOPOT006 [0.697 MB]

TUCOCK01

Beam, Multi-Beam and Broad Beam Production with COMIC Devices

99

P. Sortais, J. Angot, T. Lamy, J. Médard
LPSC, Grenoble Cedex, France
C. Peaucelle
IN2P3 IPNL, Villeurbanne, France

The COMIC discharge cavity is a very versatile technology. We will present new results and devices that match new applications like: molecular beams, ultra compact beam line for detectors calibrations, quartz source for on-line application, high voltage platform source, sputtering /assistance broad beams and finally, a quite new use, high energy multi¬-beam production for surface material modifications. In more details, we will show that the tiny discharge of COMIC can mainly produce molecular ions (H³⁺). We will present the preliminary operation of the fully quartz ISOLDE COMIC version, in collaboration with IPN-Lyon, we will present a first approach for a slit extraction version of a three cavity device, and after discussing about various extraction systems on the multi discharge device (41 cavities) we will show the low energy broad beam (2 KV) and high energy multi-beams (10 beams up to 30 KV) productions. We will specially present the different extraction systems adapted to each application and the beams characteristics which are strongly dependent on the voltage distribution of an accel-accel two electrodes extraction system.

Slides TUCOCK01 [4.960 MB]

WECOBK03

Fine Frequency Tuning of the PHOENIX Charge Breeder Used as a Probe for ECRIS Plasmas

184

T. Lamy, J. Angot, M. Marie-Jeanne, J. Médard, P. Sortais, T. Thuillier
LPSC, Grenoble Cedex, France
A. Galatà
INFN/LNL, Legnaro (PD), Italy
H. A. Koivisto, O.A. Tarvainen
JYFL, Jyväskylä, Finland

Fine frequency tuning of ECR ion sources is a main issue to optimize the production of multiply charged ion beams. The PHOENIX charge breeder operation has been tested in the range 13,75 - 14,5 GHz with an HF power of about 400 W. The effect of this tuning is analyzed by measuring the multi-ionization efficiency obtained for various characterized injected 1+ ion beams (produced by the 2.45 GHz COMIC source). The 1+/n+ method includes the capture and the multi ionization processes of the 1+ beam and may be considered as a plasma probe. The n+ spectra obtained could be considered, in first approach, as an image of the plasma of the charge breeder. However, in certain conditions it has been observed that the injection of a few hundreds of nA of 1+ ions (i.e.: Xe¹⁺) in the plasma of the charge breeder, is able to destroy the charge state distribution of the support gas (i.e.: up to 40 % of O⁶⁺ and O⁷⁺ disappears). The study of this phenomenon will be presented along with plasma potential measurements for various charge states. This study may help to understand the ECRIS creation (or destruction) of highly charged ions.

Slides WECOBK03 [7.745 MB]

Paper	Title	Page
MOPOT006	Ionization Efficiency of a COMIC Ion Source Equipped With a Quartz Plasma Chamber	51
	P. Suominen, T. Stora CERN, Geneva, Switzerland J. Médard, P. Sortais LPSC, Grenoble, France
	The ISOLDE facility at CERN produces a wide range of radioactive ion beams due to a long history on target and ion source development. Because the radioactive isotope production is very limited, the most important ion source parameters are high ionization efficiency, selectivity and reliable operation under intense radiation. Currently used ion sources (mainly laser (RILIS [1]) and arc discharge -type ion sources (VADIS [2]) do not efficiently ionize light noble gases, such as helium, and molecules, such as CO, N₂ and NO. These beams were previously planned to be produced with 1+ ECR ion sources operating at 2.45 GHz (for example MINIMONO [3]) but due to new and more efficient RF coupling of COMIC-type ion sources [4], we expect to advance in 2.45 GHz ECRIS utilization for radioactive beam production. The new COMIC source designed by LPSC, Grenoble incorporates special features such as a plasma chamber fully made of quartz (Q-COMIC). This should provide chemically good conditions for molecular ion beam production, especially for carbon. This paper presents the first ionization efficiency measurements of the Q-COMIC. [1] V.N. Fedosseev, et al, Nucl. Instrum. Methods Phys. Res. B 266/19-20 (2008) 4378. [2] PhD thesis, univ. polyt. Bucarest, L. Penescu (2009). [3] F. Wenander, W. Farabolini, G. Gaubert, P. Jardin, J. Lettry, Nucl. Phys. A, 746 (2004) 659. [4] P. Sortais, T. Lamy, J. Médard, J. Angot, L. Latrasse, and T. Thuillier, Rev. Sci. Instrum. 81 (2010) 02B314.
	Poster MOPOT006 [0.697 MB]

TUCOCK01	Beam, Multi-Beam and Broad Beam Production with COMIC Devices	99
	P. Sortais, J. Angot, T. Lamy, J. Médard LPSC, Grenoble Cedex, France C. Peaucelle IN2P3 IPNL, Villeurbanne, France
	The COMIC discharge cavity is a very versatile technology. We will present new results and devices that match new applications like: molecular beams, ultra compact beam line for detectors calibrations, quartz source for on-line application, high voltage platform source, sputtering /assistance broad beams and finally, a quite new use, high energy multi¬-beam production for surface material modifications. In more details, we will show that the tiny discharge of COMIC can mainly produce molecular ions (H³⁺). We will present the preliminary operation of the fully quartz ISOLDE COMIC version, in collaboration with IPN-Lyon, we will present a first approach for a slit extraction version of a three cavity device, and after discussing about various extraction systems on the multi discharge device (41 cavities) we will show the low energy broad beam (2 KV) and high energy multi-beams (10 beams up to 30 KV) productions. We will specially present the different extraction systems adapted to each application and the beams characteristics which are strongly dependent on the voltage distribution of an accel-accel two electrodes extraction system.
	Slides TUCOCK01 [4.960 MB]

WECOBK03	Fine Frequency Tuning of the PHOENIX Charge Breeder Used as a Probe for ECRIS Plasmas	184
	T. Lamy, J. Angot, M. Marie-Jeanne, J. Médard, P. Sortais, T. Thuillier LPSC, Grenoble Cedex, France A. Galatà INFN/LNL, Legnaro (PD), Italy H. A. Koivisto, O.A. Tarvainen JYFL, Jyväskylä, Finland
	Fine frequency tuning of ECR ion sources is a main issue to optimize the production of multiply charged ion beams. The PHOENIX charge breeder operation has been tested in the range 13,75 - 14,5 GHz with an HF power of about 400 W. The effect of this tuning is analyzed by measuring the multi-ionization efficiency obtained for various characterized injected 1+ ion beams (produced by the 2.45 GHz COMIC source). The 1+/n+ method includes the capture and the multi ionization processes of the 1+ beam and may be considered as a plasma probe. The n+ spectra obtained could be considered, in first approach, as an image of the plasma of the charge breeder. However, in certain conditions it has been observed that the injection of a few hundreds of nA of 1+ ions (i.e.: Xe¹⁺) in the plasma of the charge breeder, is able to destroy the charge state distribution of the support gas (i.e.: up to 40 % of O⁶⁺ and O⁷⁺ disappears). The study of this phenomenon will be presented along with plasma potential measurements for various charge states. This study may help to understand the ECRIS creation (or destruction) of highly charged ions.
	Slides WECOBK03 [7.745 MB]