ECRIS2016 - List of Authors (Kalvas, T.)

Paper	Title	Page
MOCO02	Broadband Microwave Emission Spectrum Associated With Kinetic Instabilities in ECR Plasmas
	I. Izotov, D. Mansfeld, V. Skalyga IAP/RAS, Nizhny Novgorod, Russia I. Izotov, V. Skalyga UNN, Nizhny Novgorod, Russia T. Kalvas, H. A. Koivisto, J. Komppula, R.J. Kronholm, J.P. Laulainen, O.A. Tarvainen JYFL, Jyväskylä, Finland
	ECRISs are susceptible to kinetic instabilities due to resonance heating mechanism forming an anisotropic electron velocity distribution function. Well-known and frequently observed extracted ion beam current oscillations in case of high heating power and/or low magnetic field gradient are proven to be caused by the instabilities of cyclotron type leading to a notable reduction of highly-charged ion beam intensities. It has been shown recently that heating power level and magnetic field gradient affect the spectrum of microwave emission of plasma related to cyclotron instabilities, being in the frequency range of 8-14 Ghz. More detailed study of microwave emission spectrum of ECR plasma conducted with an improved setup is presented in this work. It was found that frequencies of microwaves emitted by the plasma can be far beyond the primary heating frequency (14 GHz) and up to 25 GHz. Moreover, a threshold transition from periodic pulsed emission to a CW emission has been observed in the experiment for the first time, as was predicted theoretically. The transition occurs at certain threshold levels of heating microwave power and magnetic field gradient. A.G. Shalashov et all, JETP Letters, 2006, Vol. 84, No. 6, pp. 314-319 (2006)
	Slides MOCO02 [48.375 MB]
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MOCO03	Cavity Tuning Experiments with the JYFL 14 GHz ECRIS	18
	O.A. Tarvainen, T. Kalvas, H. A. Koivisto, R.J. Kronholm, J.P. Laulainen, J. Orpana JYFL, Jyväskylä, Finland I. Izotov, D. Mansfeld, V. Skalyga IAP/RAS, Nizhny Novgorod, Russia V. Toivanen CERN, Geneva, Switzerland
	Experimental results showing the effect of cavity tuning on oxygen beam currents extracted from the AECR-type JYFL 14 GHz ECRIS are reported. The microwave-plasma coupling properties of the ion source were adjusted by inserting a conducting tuner stub through the injection plug, thus changing the dimensions of the plasma chamber and affecting the cavity properties of the system. The beam currents of high charge state ions were observed to vary up to some tens of percent depending on the tuner position and the microwave frequency.
	Slides MOCO03 [5.745 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-ECRIS2016-MOCO03
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TUAO05	First Plasma of the PHOENIX V3 ECR Ion Source	48
	T. Thuillier, J. Angot, L. Bonny, J. Jacob, T. Lamy, P. Sole LPSC, Grenoble Cedex, France J.L. Flambard, L. Maunoury GANIL, Caen, France T. Kalvas JYFL, Jyväskylä, Finland C. Peaucelle IN2P3 IPNL, Villeurbanne, France
	Funding: This project was partially funded by the EU Grant Agreement 283745. PHOENIX V3 is an upgrade of the PHOENIX V2 ECR ion source granted by the European CRISP project. This new ECRIS features a larger plasma chamber and a re-duced vacuum pressure under operation. The V3 source will replace the V2 one on the SPIRAL2 accelerator in 2018. The first plasma of PHOENIX V3 was achieved on May 9th 2016. The early commissioning of the V3 source at low 18 GHz power demonstrates as expected an en-hancement of the high charge state production and Ar¹⁴⁺ intensity already exceeds the V2 one. Further enhance-ments are expected the outgassing will be achieved and the full RF power will be injected in the source.
	Slides TUAO05 [7.050 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-ECRIS2016-TUAO05
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WEPP41	Measurement of Microwave Frequencies Emitted by Instabilities of ECRIS Plasma with Waveguide Filters and Microwave Sensitive Diodes	134
	J. Orpana, T. Kalvas, H. A. Koivisto, R.J. Kronholm, J.P. Laulainen, O.A. Tarvainen JYFL, Jyväskylä, Finland I. Izotov, D. Mansfeld, V. Skalyga IAP/RAS, Nizhny Novgorod, Russia
	Periodic emission of strong microwave bursts at certain frequencies is a characteristic feature of kinetic instabilities in ECRIS plasmas. Precise measurement of the temporally evolving microwave frequency spectra requires a high bandwidth oscilloscope, which can make the experiments prohibitively expensive to conduct. An alternative low-cost method to study the microwave emission in narrow frequency bands is to apply band-pass waveguide filters and microwave sensitive diodes. The microwave emission from the plasma of the JYFL 14 GHz ECRIS has been studied with both methods. The results of the experiments are compared and their interpretation is discussed. It is demonstrated that the method based on filters and diodes can provide useful information about the microwave emission spectra induced by electron cyclotron instabilities.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-ECRIS2016-WEPP41
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Paper

Title

Page

MOCO02

Broadband Microwave Emission Spectrum Associated With Kinetic Instabilities in ECR Plasmas

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

ECRISs are susceptible to kinetic instabilities due to resonance heating mechanism forming an anisotropic electron velocity distribution function. Well-known and frequently observed extracted ion beam current oscillations in case of high heating power and/or low magnetic field gradient are proven to be caused by the instabilities of cyclotron type leading to a notable reduction of highly-charged ion beam intensities. It has been shown recently that heating power level and magnetic field gradient affect the spectrum of microwave emission of plasma related to cyclotron instabilities, being in the frequency range of 8-14 Ghz. More detailed study of microwave emission spectrum of ECR plasma conducted with an improved setup is presented in this work. It was found that frequencies of microwaves emitted by the plasma can be far beyond the primary heating frequency (14 GHz) and up to 25 GHz. Moreover, a threshold transition from periodic pulsed emission to a CW emission has been observed in the experiment for the first time, as was predicted theoretically*. The transition occurs at certain threshold levels of heating microwave power and magnetic field gradient.
*A.G. Shalashov et all, JETP Letters, 2006, Vol. 84, No. 6, pp. 314-319 (2006)

Slides MOCO02 [48.375 MB]

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MOCO03

Cavity Tuning Experiments with the JYFL 14 GHz ECRIS

18

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

Experimental results showing the effect of cavity tuning on oxygen beam currents extracted from the AECR-type JYFL 14 GHz ECRIS are reported. The microwave-plasma coupling properties of the ion source were adjusted by inserting a conducting tuner stub through the injection plug, thus changing the dimensions of the plasma chamber and affecting the cavity properties of the system. The beam currents of high charge state ions were observed to vary up to some tens of percent depending on the tuner position and the microwave frequency.

Slides MOCO03 [5.745 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-ECRIS2016-MOCO03

Export •

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TUAO05

First Plasma of the PHOENIX V3 ECR Ion Source

48

T. Thuillier, J. Angot, L. Bonny, J. Jacob, T. Lamy, P. Sole
LPSC, Grenoble Cedex, France
J.L. Flambard, L. Maunoury
GANIL, Caen, France
T. Kalvas
JYFL, Jyväskylä, Finland
C. Peaucelle
IN2P3 IPNL, Villeurbanne, France

Funding: This project was partially funded by the EU Grant Agreement 283745.
PHOENIX V3 is an upgrade of the PHOENIX V2 ECR ion source granted by the European CRISP project. This new ECRIS features a larger plasma chamber and a re-duced vacuum pressure under operation. The V3 source will replace the V2 one on the SPIRAL2 accelerator in 2018. The first plasma of PHOENIX V3 was achieved on May 9th 2016. The early commissioning of the V3 source at low 18 GHz power demonstrates as expected an en-hancement of the high charge state production and Ar¹⁴⁺ intensity already exceeds the V2 one. Further enhance-ments are expected the outgassing will be achieved and the full RF power will be injected in the source.

Slides TUAO05 [7.050 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-ECRIS2016-TUAO05

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPP41

Measurement of Microwave Frequencies Emitted by Instabilities of ECRIS Plasma with Waveguide Filters and Microwave Sensitive Diodes

134

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

Periodic emission of strong microwave bursts at certain frequencies is a characteristic feature of kinetic instabilities in ECRIS plasmas. Precise measurement of the temporally evolving microwave frequency spectra requires a high bandwidth oscilloscope, which can make the experiments prohibitively expensive to conduct. An alternative low-cost method to study the microwave emission in narrow frequency bands is to apply band-pass waveguide filters and microwave sensitive diodes. The microwave emission from the plasma of the JYFL 14 GHz ECRIS has been studied with both methods. The results of the experiments are compared and their interpretation is discussed. It is demonstrated that the method based on filters and diodes can provide useful information about the microwave emission spectra induced by electron cyclotron instabilities.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-ECRIS2016-WEPP41

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)