ECRIS2012 - List of Keywords (electron)

Paper	Title	Other Keywords	Page
TUYO01	Experimental Study of Temperature and Density Evolution During Breakdown in a 2.45 GHz ECR Plasma	plasma, coupling, diagnostics, ion	13
	O.D. Cortázar, A. Megía-Macías, A. Vizcaíno-de-Julián ESS Bilbao, LEIOA, Spain
	An experimental study of temperature and density evolution during breakdown in off-resonance ECR hydrogen plasma by time resolved Langmuir probe diagnostic is presented. Under square 2.45 GHz microwave excitation pulses with a frequency of 50 Hz and relative high microwave power, unexpected transient temperature peaks that reach 18 eV during 20 μs are reported at very beginning of plasma breakdown. Decays of such peaks reach final stable temperatures of 5 eV at flat top microwave excitation pulse. Evidence of interplay between incoming power and duty cycle giving different kind of plasma parameters evolutions engaged to microwave coupling times is observed. Under relative high power conditions where short microwave coupling times are recorded, high temperature peaks are measured. However, for lower incoming powers and longer coupling times, temperature evolves gradually to a higher final temperature without peaking. On the other hand, the early instant where temperature peaks are observed also suggest a possible connection with preglow and superadiabatic processes during breakdown in ECR plasmas.
	Slides TUYO01 [6.674 MB]

TUYO02	Control of the Plasma Transversal Losses, Caused by MHD Instabilities, in Open Mirror Magnetic Trap of the ECRIS: Recent Experiments on SMIS 37 Setup	plasma, ion, ECR, ion-source	18
	V. Sidorov, I. Izotov, S. Razin, V. Skalyga, V. Zorin IAP/RAS, Nizhny Novgorod, Russia
	Funding: This work was partially performed in the framework of the Federal Targeted Program 'Scientific and Educational Personnel of the Innovative Russia' for 2009-2013 This work is a continuation of the experiments described in [1, 2] and aimed at the investigation of the new conceptions of MHD stabilization of plasma in open axisymmetric traps, specifically, it is aimed at the investigation of the shear flow influence on the transport control in open mirror traps. As in previous experiments, shear flow was created by limiter-electrode with bias potential according to the vacuum chamber. Plasma density structure in radial and azimuthal directions was studied. Mode structure of the perturbations was investigated. Substantial sharp shift of the plasma density maximum to the system axis with bias potential growth was demonstrated. It was shown, that the value of the bias potential that corresponds to the plasma density profile shift grows with the magnetic field growth that can be interpreted as the electron temperature growth. Some theoretical estimations of the influence of the transversal losses decrease on plasma parameters were made. [1] A.Sidorov, P.Bagryansky, A.Beklemishev et al. Trans. Fusion Sci. and Technology, 59, 112, (2011). [2] I.Izotov, S.Razin, A.Sidorov et al. Rev. Sci. Instrum., 83, 02A318 (2012).
	Slides TUYO02 [1.542 MB]

TUYO03	Secondary-electron-enhanced Plasma as an Alternative to Double/Variable-frequency Heating in ECRIS	plasma, ECRIS, ion, experiment	22
	K.E. Stiebing IKF, Frankfurt-am-Main, Germany S. Dobrescu, L. Schächter IFIN, Magurele- Bucuresti, Romania
	As "double frequency heating" (DFH) now has become the method of choice to optimize the output from the newest generation ECRIS, it was a challenge to compare this method with the comparatively cheap method of "metal dielectric" (MD) structures introduced into the plasma chamber, which has also proven to strongly enrich the plasma with electrons that are effectively trapped and heated. Two RF-systems have been launched to the 14 GHz ECRIS, however, not allowing RF-differences as large as 1.5 GHz as demanded for DFH. Therefore the source was operated in a "frequency tuning" mode (FT) by optimizing the frequency difference by the output of Ar¹⁴⁺ ions. The data without and with MD-configuration are compared and related to data for the DFH. On the basis of Bremsstrahlung radiation spectroscopy and charge state analysis, it turned out that the FT-mode does not change the source performance substantially. The measured effects are in the order of 20% to 30% as reported elsewhere. In contrast to this, the enhancement gained by the MD method is much higher. The measured enhancement ratios even surpass those reported for real double frequency heating.
	Slides TUYO03 [5.642 MB]

TUYO04	Neutral Gas Temperature Measurements of a Radio Frequency Micro-thruster	plasma, ion, background, vacuum	25
	A.D. Greig, R.W. Boswell, C. Charles, R.P. Hawkins SP3, Canberra, Australia M.D. Bowden, Y.C. Sutton The Open University, Milton Keynes, United Kingdom
	A radio frequency (13.56 MHz) capacitively coupled cylindrical argon plasma discharge was analysed using optical emission spectroscopy (OES) for various powers and pressures in the ranges 10 W to 40 W and 0.5 Torr to 5 Torr. Trace amounts of nitrogen were added to the discharge to estimate the temperature of the neutrals using rovibrational band matching of the 2^nd positive system of nitrogen and the 1^st negative system of nitrogen ions. Comparing simulated computer generated spectra of these bands to experimentally measured spectra determined the rotational and vibrational temperatures of the nitrogen, from which the temperature of the neutrals was inferred by assuming the rotational temperature was the same as the neutral gas temperature.
	Slides TUYO04 [1.341 MB]

TUZO04	Space Charge Compensation Measurements of Multicharged Ion Beams Extracted from an ECR Ion Source	ion, space-charge, ECR, simulation	38
	D. Winklehner LBNL, Berkeley, California, USA D.G. Cole, D. Leitner, G. Machicoane, F. Marti, L. Tobos NSCL, East Lansing, Michigan, USA
	Space charge compensation* due to the interaction of the beam with residual gas molecules is a well-known phenomenon for high current injector beam lines. For beam lines using mostly magnetic focusing elements and for pressure above 10^-6 mbar, full neutralization has been observed. However, due to the low pressure required for the efficient transport of high charge state ions, beams in ECR injector lines are typically only partly neutralized. With the performance increase of the next generation ECR ion sources it is possible to extract tens of mA of beam current. In this high current regime, non-linear focusing effects due to the space-charge potential of the beam become more and more important. In order to develop a realistic simulation model for low energy beam transport lines, it is important to estimate the degree of space charge compensation. In this contribution we report on measurements of the beam potential (and neutralization), performed after the extraction region of the ECR ion source, in dependence of the base pressure in the beam line and other source parameters using a Retarding Field Analyzer (RFA). Results are discussed and compared to simulations. * When the beam interacts with the residual gas, electrons are separated from gas molecules and accumulate inside the beam envelope, thereby compensating the space-charge (aka neutralization)
	Slides TUZO04 [4.192 MB]

WEXO02	Recent Developments and Electron Density Simulations at the ATOMKI 14.5 GHz ECRIS	plasma, ion, simulation, ECRIS	77
	S. Biri, R. Rácz ATOMKI, Debrecen, Hungary J. Pálinkás University Debrecen, Debrecen, Hungary
	The 14.5 GHz ECR ion source of ATOMKI is a standard room-temperature ECRIS devoted for plasma diagnostic studies, for atomic physics research and also serves as a particle source with wide range of elements for surface treatments. From the beginning lots of technical modifications and developments have been carried out on the ion source. The changes aimed the increasing of the beams charge, intensity and the widening of the ion choice. Other modifications were done to develop special, non-standard operation modes or to produce peculiar plasmas or beams. Recently the original NdFeB hexapole was exchanged by a new one and new iron plugs were calculated, designed and installed at the injection side of the source. The resulted stronger magnetic trap has shown significant effect on the beam intensity and on the charge states distribution. The new magnetic configuration was re-calculated by the TrapCAD code developed by our group. The spatial movement and energy evolution of a high number of electrons were followed in the calculation. A post-calculation energy filtering carried out for the lost and non-lost electrons reveals numerous interesting and important information in 3D.
	Slides WEXO02 [11.678 MB]

WEXO05	Effect of Source Tuning Parameters on the Plasma Potential of Heavy Ions and its Influence on the Longitudinal Optics of the High Current Injector	plasma, ion, rfq, emittance	90
	G.O. Rodrigues, D. Kanjilal, P.S. Lakshmy, A. Mandal, Y. Mathur, A. Roy IUAC, New Delhi, India R. Baskaran IGCAR, Channai, India
	Plasma potentials for various heavy ions have been measured using the retarding field technique in the 18 GHz High Temperature Superconducting ECR ion source, PKDELIS. The influence of various source parameters viz., RF power, gas pressure, magnetic field, negative DC bias and gas mixing on the plasma potential is studied. It is observed that the plasma potentials are decreasing for increasing charge states and a mass effect is clearly observed for the ions with similar operating gas pressures. In the case of gas mixing, it is observed that the plasma potential minimises at an optimum value of the gas pressure of the mixing gas and the mean charge state maximises at this value. The energy spread arising from the plasma potential influences the longitudinal optics of the high current injector in terms of increased phase spread which deteriorates the transmission through the RFQ. Details of the measurements carried out as a function of various source parameters and its impact on the longitudinal optics are presented.
	Slides WEXO05 [11.394 MB]

WEYO03	Ion Beam Extraction from Magnetized Plasma	plasma, ion, extraction, ion-source	106
	P. Spädtke, R. Lang, J. Mäder, F. Maimone, J. Roßbach, K. Tinschert GSI, Darmstadt, Germany
	With increasing the total extracted current for any ion source, the optimisation of the extraction system becomes more important, because of the space charge effect. Several attempts have been made in the past to simulate the extraction from an Electron Cyclotron Resonance Ion Source (ECRIS) in a correct way. Most of these attempts failed, because they were not able to reproduce the experimental results. The best model up to now is given by the following procedure: tracing the magnetic field lines through the extraction aperture, looking where these field lines are coming from; using these coordinates of the magnetic field line as starting points for ions to be extracted; the initial current of each trajectory is determined by theoretical assumptions about the plasma or by a plasma simulation; Child's law is applicable locally only in direction of the magnetic field, if no emission limited flow is present.
	Slides WEYO03 [16.955 MB]

WEPP03	Plasma Instability in the Afterglow of ECR Discharge Sustained in a Mirror Trap	plasma, ion, ECR, detector	125
	I. Izotov, A. Mansfeld, V. Skalyga, V. Zorin IAP/RAS, Nizhny Novgorod, Russia T. Grahn, T. Kalvas, H. A. Koivisto, J.P.O. Komppula, P. Peura, O.A. Tarvainen, V. Toivanen JYFL, Jyväskylä, Finland
	Funding: Work was performed in frame of realization of federal targeted program "Scientific and pedagogical labor force for an innovative Russia" for 2009-2013 yy. A number of studies have been devoted to the investigations of plasma decay in ECR heated discharges confined in a mirror magnetic trap. The motivation of this work is to study plasma instabilities causing perturbations of ion current during the plasma decay. Present work is devoted to time-resolved diagnostics of non-linear effects observed during the afterglow plasma decay of an 14 GHz Electron Cyclotron Resonance Ion Source (ECRIS) at JYFL operated in pulsed mode. Plasma instabilities causing perturbations of extracted ion current during the decay were observed and studied. It is shown that these perturbations are associated with precipitation of high energy electrons along the magnetic field lines and strong bursts of bremsstrahlung emission. The effect of ion source settings on the onset of the observed instabilities was investigated. Based on the experimental data and estimated plasma properties it is assumed that the instabilities are of cyclotron type. The conclusion is supported by a comparison to other type of plasma devices (SMIS 37, IAP RAS) exhibiting similar characteristics but operating in a different plasma confinement regime.

WEPP16	Experimental Studies on the ALISES Ion Source at CEA Saclay	plasma, ion, ion-source, extraction	143
	O. Tuske, O. Delferrière, Y. Gauthier, R. Gobin, F. Harrault, J.L. Jannin CEA/DSM/IRFU, France S. Nyckees CEA/IRFU, Gif-sur-Yvette, France
	The ALISES ion source was originally designed to reduce beam emittance at RFQ entrance by shortened the length of the LEBT. A wide opened magnetic coil at ground potential produces the fringe field needed for the ECR heating at 2.45 GHz frequency. The first part describes the commissioning of the source: Penning discharges inside the accelerating column make the high voltage power supply collapse. Experimental tests with kapton films while discharges occur, and simulations with OPERA-3D code have shown great similarities to detect the location of those discharges and allow us to make the ion source work. The second part of this paper will present the result of low intensity light ion beam production versus the plasma chamber length and radius. Those very preliminary tests give us indications to reduce the ion source dimensions.
	Poster WEPP16 [2.556 MB]

FRYA03	ECRIS Related Research and Development Work at JYFL and Some Future Prospects	ion, plasma, ion-source, photon	203
	H. A. Koivisto, J. Ärje, T. Kalvas, J.P.O. Komppula, R.J. Kronholm, J.P. Laulainen, O.A. Tarvainen, V. Toivanen JYFL, Jyväskylä, Finland
	Since the last ECR workshop the JYFL ion source group has focused on the plasma research, work on the ion beam formation and transport and development of metal ion beams. The plasma research can be divided into plasma breakdown processes, plasma and ion beam instabilities and afterglow processes. The afterglow and instability experiments will be presented elsewhere in these proceedings [1]. In addition, studies involving in the photoelectric induced electron emission and charge exchange reactions will be briefly discussed and the experiments concerning the resonance properties of empty and plasma loaded cavity will be presented. An improvement in ion beam transport of the JYFL K130 cyclotron facility was achieved as a result of the work performed on ion beam formation. This work will be described in more detailed elsewhere in these proceedings [2]. The MIVOC method and sputtering technique were further studied in order to produce intensive titanium ion beams. As a result, an intensive {50}Ti ion beam was successfully produced with the MIVOC method and interesting behavior regarding the sputtering was noticed. [1] V. Skalyga et al. and O. Tarvainen et al. [2] V. Toivanen et al.
	Slides FRYA03 [4.159 MB]

Paper

Title

Other Keywords

Page

TUYO01

Experimental Study of Temperature and Density Evolution During Breakdown in a 2.45 GHz ECR Plasma

plasma, coupling, diagnostics, ion

13

O.D. Cortázar, A. Megía-Macías, A. Vizcaíno-de-Julián
ESS Bilbao, LEIOA, Spain

An experimental study of temperature and density evolution during breakdown in off-resonance ECR hydrogen plasma by time resolved Langmuir probe diagnostic is presented. Under square 2.45 GHz microwave excitation pulses with a frequency of 50 Hz and relative high microwave power, unexpected transient temperature peaks that reach 18 eV during 20 μs are reported at very beginning of plasma breakdown. Decays of such peaks reach final stable temperatures of 5 eV at flat top microwave excitation pulse. Evidence of interplay between incoming power and duty cycle giving different kind of plasma parameters evolutions engaged to microwave coupling times is observed. Under relative high power conditions where short microwave coupling times are recorded, high temperature peaks are measured. However, for lower incoming powers and longer coupling times, temperature evolves gradually to a higher final temperature without peaking. On the other hand, the early instant where temperature peaks are observed also suggest a possible connection with preglow and superadiabatic processes during breakdown in ECR plasmas.

Slides TUYO01 [6.674 MB]

TUYO02

Control of the Plasma Transversal Losses, Caused by MHD Instabilities, in Open Mirror Magnetic Trap of the ECRIS: Recent Experiments on SMIS 37 Setup

plasma, ion, ECR, ion-source

18

V. Sidorov, I. Izotov, S. Razin, V. Skalyga, V. Zorin
IAP/RAS, Nizhny Novgorod, Russia

Funding: This work was partially performed in the framework of the Federal Targeted Program 'Scientific and Educational Personnel of the Innovative Russia' for 2009-2013
This work is a continuation of the experiments described in [1, 2] and aimed at the investigation of the new conceptions of MHD stabilization of plasma in open axisymmetric traps, specifically, it is aimed at the investigation of the shear flow influence on the transport control in open mirror traps. As in previous experiments, shear flow was created by limiter-electrode with bias potential according to the vacuum chamber. Plasma density structure in radial and azimuthal directions was studied. Mode structure of the perturbations was investigated. Substantial sharp shift of the plasma density maximum to the system axis with bias potential growth was demonstrated. It was shown, that the value of the bias potential that corresponds to the plasma density profile shift grows with the magnetic field growth that can be interpreted as the electron temperature growth. Some theoretical estimations of the influence of the transversal losses decrease on plasma parameters were made.
[1] A.Sidorov, P.Bagryansky, A.Beklemishev et al. Trans. Fusion Sci. and Technology, 59, 112, (2011).
[2] I.Izotov, S.Razin, A.Sidorov et al. Rev. Sci. Instrum., 83, 02A318 (2012).

Slides TUYO02 [1.542 MB]

TUYO03

Secondary-electron-enhanced Plasma as an Alternative to Double/Variable-frequency Heating in ECRIS

plasma, ECRIS, ion, experiment

22

K.E. Stiebing
IKF, Frankfurt-am-Main, Germany
S. Dobrescu, L. Schächter
IFIN, Magurele- Bucuresti, Romania

As "double frequency heating" (DFH) now has become the method of choice to optimize the output from the newest generation ECRIS, it was a challenge to compare this method with the comparatively cheap method of "metal dielectric" (MD) structures introduced into the plasma chamber, which has also proven to strongly enrich the plasma with electrons that are effectively trapped and heated. Two RF-systems have been launched to the 14 GHz ECRIS, however, not allowing RF-differences as large as 1.5 GHz as demanded for DFH. Therefore the source was operated in a "frequency tuning" mode (FT) by optimizing the frequency difference by the output of Ar¹⁴⁺ ions. The data without and with MD-configuration are compared and related to data for the DFH. On the basis of Bremsstrahlung radiation spectroscopy and charge state analysis, it turned out that the FT-mode does not change the source performance substantially. The measured effects are in the order of 20% to 30% as reported elsewhere. In contrast to this, the enhancement gained by the MD method is much higher. The measured enhancement ratios even surpass those reported for real double frequency heating.

Slides TUYO03 [5.642 MB]

TUYO04

Neutral Gas Temperature Measurements of a Radio Frequency Micro-thruster

plasma, ion, background, vacuum

25

A.D. Greig, R.W. Boswell, C. Charles, R.P. Hawkins
SP3, Canberra, Australia
M.D. Bowden, Y.C. Sutton
The Open University, Milton Keynes, United Kingdom

A radio frequency (13.56 MHz) capacitively coupled cylindrical argon plasma discharge was analysed using optical emission spectroscopy (OES) for various powers and pressures in the ranges 10 W to 40 W and 0.5 Torr to 5 Torr. Trace amounts of nitrogen were added to the discharge to estimate the temperature of the neutrals using rovibrational band matching of the 2^nd positive system of nitrogen and the 1^st negative system of nitrogen ions. Comparing simulated computer generated spectra of these bands to experimentally measured spectra determined the rotational and vibrational temperatures of the nitrogen, from which the temperature of the neutrals was inferred by assuming the rotational temperature was the same as the neutral gas temperature.

Slides TUYO04 [1.341 MB]

TUZO04

Space Charge Compensation Measurements of Multicharged Ion Beams Extracted from an ECR Ion Source

ion, space-charge, ECR, simulation

38

D. Winklehner
LBNL, Berkeley, California, USA
D.G. Cole, D. Leitner, G. Machicoane, F. Marti, L. Tobos
NSCL, East Lansing, Michigan, USA

Space charge compensation* due to the interaction of the beam with residual gas molecules is a well-known phenomenon for high current injector beam lines. For beam lines using mostly magnetic focusing elements and for pressure above 10^-6 mbar, full neutralization has been observed. However, due to the low pressure required for the efficient transport of high charge state ions, beams in ECR injector lines are typically only partly neutralized. With the performance increase of the next generation ECR ion sources it is possible to extract tens of mA of beam current. In this high current regime, non-linear focusing effects due to the space-charge potential of the beam become more and more important. In order to develop a realistic simulation model for low energy beam transport lines, it is important to estimate the degree of space charge compensation. In this contribution we report on measurements of the beam potential (and neutralization), performed after the extraction region of the ECR ion source, in dependence of the base pressure in the beam line and other source parameters using a Retarding Field Analyzer (RFA). Results are discussed and compared to simulations.
* When the beam interacts with the residual gas, electrons are separated from gas molecules and accumulate inside the beam envelope, thereby compensating the space-charge (aka neutralization)

Slides TUZO04 [4.192 MB]

WEXO02

Recent Developments and Electron Density Simulations at the ATOMKI 14.5 GHz ECRIS

plasma, ion, simulation, ECRIS

77

S. Biri, R. Rácz
ATOMKI, Debrecen, Hungary
J. Pálinkás
University Debrecen, Debrecen, Hungary

The 14.5 GHz ECR ion source of ATOMKI is a standard room-temperature ECRIS devoted for plasma diagnostic studies, for atomic physics research and also serves as a particle source with wide range of elements for surface treatments. From the beginning lots of technical modifications and developments have been carried out on the ion source. The changes aimed the increasing of the beams charge, intensity and the widening of the ion choice. Other modifications were done to develop special, non-standard operation modes or to produce peculiar plasmas or beams. Recently the original NdFeB hexapole was exchanged by a new one and new iron plugs were calculated, designed and installed at the injection side of the source. The resulted stronger magnetic trap has shown significant effect on the beam intensity and on the charge states distribution. The new magnetic configuration was re-calculated by the TrapCAD code developed by our group. The spatial movement and energy evolution of a high number of electrons were followed in the calculation. A post-calculation energy filtering carried out for the lost and non-lost electrons reveals numerous interesting and important information in 3D.

Slides WEXO02 [11.678 MB]

WEXO05

Effect of Source Tuning Parameters on the Plasma Potential of Heavy Ions and its Influence on the Longitudinal Optics of the High Current Injector

plasma, ion, rfq, emittance

90

G.O. Rodrigues, D. Kanjilal, P.S. Lakshmy, A. Mandal, Y. Mathur, A. Roy
IUAC, New Delhi, India
R. Baskaran
IGCAR, Channai, India

Plasma potentials for various heavy ions have been measured using the retarding field technique in the 18 GHz High Temperature Superconducting ECR ion source, PKDELIS. The influence of various source parameters viz., RF power, gas pressure, magnetic field, negative DC bias and gas mixing on the plasma potential is studied. It is observed that the plasma potentials are decreasing for increasing charge states and a mass effect is clearly observed for the ions with similar operating gas pressures. In the case of gas mixing, it is observed that the plasma potential minimises at an optimum value of the gas pressure of the mixing gas and the mean charge state maximises at this value. The energy spread arising from the plasma potential influences the longitudinal optics of the high current injector in terms of increased phase spread which deteriorates the transmission through the RFQ. Details of the measurements carried out as a function of various source parameters and its impact on the longitudinal optics are presented.

Slides WEXO05 [11.394 MB]

WEYO03

Ion Beam Extraction from Magnetized Plasma

plasma, ion, extraction, ion-source

106

P. Spädtke, R. Lang, J. Mäder, F. Maimone, J. Roßbach, K. Tinschert
GSI, Darmstadt, Germany

With increasing the total extracted current for any ion source, the optimisation of the extraction system becomes more important, because of the space charge effect. Several attempts have been made in the past to simulate the extraction from an Electron Cyclotron Resonance Ion Source (ECRIS) in a correct way. Most of these attempts failed, because they were not able to reproduce the experimental results. The best model up to now is given by the following procedure: tracing the magnetic field lines through the extraction aperture, looking where these field lines are coming from; using these coordinates of the magnetic field line as starting points for ions to be extracted; the initial current of each trajectory is determined by theoretical assumptions about the plasma or by a plasma simulation; Child's law is applicable locally only in direction of the magnetic field, if no emission limited flow is present.

Slides WEYO03 [16.955 MB]

WEPP03

Plasma Instability in the Afterglow of ECR Discharge Sustained in a Mirror Trap

plasma, ion, ECR, detector

125

I. Izotov, A. Mansfeld, V. Skalyga, V. Zorin
IAP/RAS, Nizhny Novgorod, Russia
T. Grahn, T. Kalvas, H. A. Koivisto, J.P.O. Komppula, P. Peura, O.A. Tarvainen, V. Toivanen
JYFL, Jyväskylä, Finland

Funding: Work was performed in frame of realization of federal targeted program "Scientific and pedagogical labor force for an innovative Russia" for 2009-2013 yy.
A number of studies have been devoted to the investigations of plasma decay in ECR heated discharges confined in a mirror magnetic trap. The motivation of this work is to study plasma instabilities causing perturbations of ion current during the plasma decay. Present work is devoted to time-resolved diagnostics of non-linear effects observed during the afterglow plasma decay of an 14 GHz Electron Cyclotron Resonance Ion Source (ECRIS) at JYFL operated in pulsed mode. Plasma instabilities causing perturbations of extracted ion current during the decay were observed and studied. It is shown that these perturbations are associated with precipitation of high energy electrons along the magnetic field lines and strong bursts of bremsstrahlung emission. The effect of ion source settings on the onset of the observed instabilities was investigated. Based on the experimental data and estimated plasma properties it is assumed that the instabilities are of cyclotron type. The conclusion is supported by a comparison to other type of plasma devices (SMIS 37, IAP RAS) exhibiting similar characteristics but operating in a different plasma confinement regime.

WEPP16

Experimental Studies on the ALISES Ion Source at CEA Saclay

plasma, ion, ion-source, extraction

143

O. Tuske, O. Delferrière, Y. Gauthier, R. Gobin, F. Harrault, J.L. Jannin
CEA/DSM/IRFU, France
S. Nyckees
CEA/IRFU, Gif-sur-Yvette, France

The ALISES ion source was originally designed to reduce beam emittance at RFQ entrance by shortened the length of the LEBT. A wide opened magnetic coil at ground potential produces the fringe field needed for the ECR heating at 2.45 GHz frequency. The first part describes the commissioning of the source: Penning discharges inside the accelerating column make the high voltage power supply collapse. Experimental tests with kapton films while discharges occur, and simulations with OPERA-3D code have shown great similarities to detect the location of those discharges and allow us to make the ion source work. The second part of this paper will present the result of low intensity light ion beam production versus the plasma chamber length and radius. Those very preliminary tests give us indications to reduce the ion source dimensions.

Poster WEPP16 [2.556 MB]

FRYA03

ECRIS Related Research and Development Work at JYFL and Some Future Prospects

ion, plasma, ion-source, photon

203

H. A. Koivisto, J. Ärje, T. Kalvas, J.P.O. Komppula, R.J. Kronholm, J.P. Laulainen, O.A. Tarvainen, V. Toivanen
JYFL, Jyväskylä, Finland

Since the last ECR workshop the JYFL ion source group has focused on the plasma research, work on the ion beam formation and transport and development of metal ion beams. The plasma research can be divided into plasma breakdown processes, plasma and ion beam instabilities and afterglow processes. The afterglow and instability experiments will be presented elsewhere in these proceedings [1]. In addition, studies involving in the photoelectric induced electron emission and charge exchange reactions will be briefly discussed and the experiments concerning the resonance properties of empty and plasma loaded cavity will be presented. An improvement in ion beam transport of the JYFL K130 cyclotron facility was achieved as a result of the work performed on ion beam formation. This work will be described in more detailed elsewhere in these proceedings [2]. The MIVOC method and sputtering technique were further studied in order to produce intensive titanium ion beams. As a result, an intensive {50}Ti ion beam was successfully produced with the MIVOC method and interesting behavior regarding the sputtering was noticed.
[1] V. Skalyga et al. and O. Tarvainen et al.
[2] V. Toivanen et al.

Slides FRYA03 [4.159 MB]