ECRIS2010 - List of Keywords (radiation)

Paper	Title	Other Keywords	Page
MOCOBK03	Status of Ion Sources at HIMAC	ion, ion-source, ECR, plasma	20
	A. Kitagawa, M. Muramatsu, Y. Sakamoto NIRS, Chiba-shi, Japan S. Biri ATOMKI, Debrecen, Hungary A.G. Drentje KVI, Groningen, The Netherlands T.F. Fujita National Institute of Radiological Sciences, Chiba, Japan T. Sakuma, N. Sasaki, T. Sasano, W. Takasugi AEC, Chiba, Japan
	Since 1994, heavy-ion radiotherapy using carbon ions is successfully carried out with the Heavy Ion Medical Accelerator in Chiba (HIMAC) at the National Institute of Radiological Sciences (NIRS). Over 5000 cancer patients have already been treated with 140-400 MeV/u carbon beams. These clinical results have clearly verified the advantages of carbon ion. The ion source needs to realize a stable beam with the same conditions for daily operation. Maintenance is restricted to once per year. However, the deposition of carbon on the wall of the plasma chamber is normally unavoidable. This causes an ‘anti-wall-coating effect’, i.e. a decreasing of the beam (typically 50 % after a few months of operation), especially for the higher charge-state ions due to the surface material of the wall. The ion source has - even in this bad condition – still to produce a sufficiently intense and stable beam. We summarize our experience during 16 years of operation and show the scope for further developments. HIMAC is dedicated to radiotherapy, but it has as a second essential task to operate as a facility for physicist users. In that scope it accelerates many ion species for basic experiments. In order to serve all HIMAC users at best, the extension of the range of ion species is an important subject in ion source development. For example, in order to increase the ECRIS-beam intensity for heavier ions, microwave is applied at different frequencies by a traveling wave tube amplifier and….?
	Slides MOCOBK03 [2.780 MB]

MOPOT008	He²⁺ Source Based on Penning Discharge with Additional 75 GHz ECR Heating	plasma, ECR, ion	54
	A. Vodopyanov, S. Golubev, I. Izotov, A. Mansfeld IAP/RAS, Nizhny Novgorod, Russia G. Yushkov Institute of High Current Electronics, Tomsk, Russia
	It is well known that one can reach high average charge of ions in the ECR plasma by increasing plasma density and decreasing neutral gas pressure. ECR discharge could be realized at very low gas pressure, but discharge startup takes longer time when gas pressure is low. So, it is impossible to realize ECR discharge with limited microwave heating pulse duration at gas pressure lower certain threshold value. This problem could be solved with help of trigger plasma, which should be ignited at low gas pressure in the trap with high magnetic field. This fore plasma could help to decrease ECR plasma startup time significantly and make it possible to realize ECR plasma at very low pressure in pulse operation regime. We suggest penning type discharge as a trigger discharge for fast startup of pulsed ECR plasma. Penning type discharge glows at as low pressure as needed. Discharge was realized in the simple mirror magnetic trap at pressure about 10^-5 mbar. Helium was used as an operating gas. Significant plasma density (about 10¹¹ cm^-3) was obtained at the moment just before microwave heating pulse started. Gyrotron radiation with frequency of 75 GHz, microwave power up to 200 kW and pulse duration up to 1 ms, was used for plasma heating. In the present work the fully striped helium ions were demonstrated, average charge of ions in the plasma was equal 2. Temporal evolution of charge state distribution was investigated. Charge state distribution over helium pressure was also studied.
	Poster MOPOT008 [0.535 MB]

TUCOBK01	Preglow Phenomenon Origins and its Scaling for Ecris	plasma, ion, electron, ECR	87
	I. Izotov, V. Sidorov, V. Skalyga, V. Zorin IAP/RAS, Nizhny Novgorod, Russia
	Preglow effect investigation is one of topical directions of ECR ion sources development at present. Preglow is of interest for efficient short-pulsed multi-charged ion source creation. Particularly, such source of intense beams of short-living radioactive isotopes multi-charged ions is one of key elements in “Beta-Beam” European project [1]. Use of Preglow-generating regime of an ECRIS operation is a promising way of pulsed high-intense multi-charged ion beams production with much shorter edges in comparison with usual operation regime. The first theoretical investigations of Preglow phenomenon were performed in references [2,3]. Present work describes modified model of ECR discharge development in a magnetic trap of the ECRIS as a continuation of [2,3]. Numerical simulations made with the updated model allow authors to propose more physical and intuitive explanation of Preglow phenomenon origins. Obtained dependences of Preglow characteristics on experimental conditions offer a scaling for a wide range of ECRISes. [1] (ONLINE) http://beta-beam.web.cern.ch/beta-beam/task/diverse/mandate.htm [2] T. Thuillier et al, Rev. of Sci. Instrum., 79, 02A314, 2008. [3] I. Izotov et al, IEEE Trans. Plasma Sci. 36, 1494, 2008.
	Slides TUCOBK01 [0.928 MB]

TUCOBK02	“Preglow” Investigation in ECR Discharge at 37 GHz, 100 kW	ion, plasma, ECR, ion-source	90
	V. Skalyga, I. Izotov, S. Razin, V. Sidorov, V. Zorin IAP/RAS, Nizhny Novgorod, Russia T. Lamy, T. Thuillier LPSC, Grenoble, France
	Multicharged ion beams generation in "Preglow" regime is now considered as the main way of short pulsed ion source creation for “Beta Beam” project. The "Preglow" effect has been investigated at a several laboratories (LPSC, JYFL, IAP RAS). The effect was discovered at LPSC on PHOENIX ion source using 18 GHz radiation for plasma heating. Investigations at 14 GHz frequency were made at JYFL. Theoretical analysis demonstrated the advantage of MW frequency increase. Theoretical calculations predict possibility of "Preglow" peaks generation with duration about tens microseconds and rather high average ion charge. At present time at LPSC a joint construction of a new generation ECR ion source with 60 GHz gyrotron plasma heating is running. As a continuation of previous research at 14, 18 and 28 GHz at present work results of experimental and theoretical "Preglow" effect investigations at SMIS 37 setup with 37,5 GHz MW plasma heating are reported. Received data are important as fundamental result in physics of ECRISs and at the same time it is the next step on the way of 60 GHz SEISM facility creation. “Preglow” effect was observed and investigated in experiments with ECR discharge stimulated with gyrotron radiation @ 37.5 GHz, 100 kW. Received dependencies of the “Preglow” parameters are in good correspondence with results of numerical simulations. It was shown in experiments that generation of “Preglow” peak with duration about 30 μs is possible.
	Slides TUCOBK02 [2.338 MB]

TUPOT009	Measurements of Bremsstrahlung Radiation and X-Ray Heat Load to Cryostat on SECRAL	ion, electron, ECR, plasma	134
	H. Zhao, Y. Cao, X.X. Li, D. Xie, W.H. Zhang, X.Z. Zhang, H.W. Zhao, Y.H. Zhu IMP, Lanzhou, People's Republic of China W. Lu Graduate School of the Chinese Academy of Sciences, Beijing, People's Republic of China
	Measurement of Bremsstrahlung radiation from ECR plasma can yield certain information of the ECR heating process and a plausible estimate of the X-ray heat load to the cryostat of a superconducting ECR source which needs seriously addressed. With a newly-developed collimation system, which defines a narrower spatial range of the measurement and provides an effective shielding from the background, a systematic measurement of the Bremmstrahlung emitted axially from the SECRAL (Superconducting ECR Ion Source with Advanced design in Lanzhou) plasma were carried out recently. The spectral temperature Tspe, a relative index of mean energy of the plasma hot electrons, was derived through linear fitting of the spectra in semi-logarithm coordinates. This article will present and discuss the evolutions of the X-ray flux and the hot electron energy with various source parameters, such as heating frequency, RF power and magnetic field configuration. And possible solutions to reduce the X-ray heat load induced by Bremsstrahlung radiation are proposed and discussed.
	Poster TUPOT009 [1.581 MB]

WECOAK04	Bremsstrahlung and Ion Beam Current Measurements With SuSI ECR Ion Source	plasma, collimation, ion, extraction	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]

Paper

Title

Other Keywords

Page

MOCOBK03

Status of Ion Sources at HIMAC

ion, ion-source, ECR, plasma

20

A. Kitagawa, M. Muramatsu, Y. Sakamoto
NIRS, Chiba-shi, Japan
S. Biri
ATOMKI, Debrecen, Hungary
A.G. Drentje
KVI, Groningen, The Netherlands
T.F. Fujita
National Institute of Radiological Sciences, Chiba, Japan
T. Sakuma, N. Sasaki, T. Sasano, W. Takasugi
AEC, Chiba, Japan

Since 1994, heavy-ion radiotherapy using carbon ions is successfully carried out with the Heavy Ion Medical Accelerator in Chiba (HIMAC) at the National Institute of Radiological Sciences (NIRS). Over 5000 cancer patients have already been treated with 140-400 MeV/u carbon beams. These clinical results have clearly verified the advantages of carbon ion. The ion source needs to realize a stable beam with the same conditions for daily operation. Maintenance is restricted to once per year. However, the deposition of carbon on the wall of the plasma chamber is normally unavoidable. This causes an ‘anti-wall-coating effect’, i.e. a decreasing of the beam (typically 50 % after a few months of operation), especially for the higher charge-state ions due to the surface material of the wall. The ion source has - even in this bad condition – still to produce a sufficiently intense and stable beam. We summarize our experience during 16 years of operation and show the scope for further developments. HIMAC is dedicated to radiotherapy, but it has as a second essential task to operate as a facility for physicist users. In that scope it accelerates many ion species for basic experiments. In order to serve all HIMAC users at best, the extension of the range of ion species is an important subject in ion source development. For example, in order to increase the ECRIS-beam intensity for heavier ions, microwave is applied at different frequencies by a traveling wave tube amplifier and….?

Slides MOCOBK03 [2.780 MB]

MOPOT008

He²⁺ Source Based on Penning Discharge with Additional 75 GHz ECR Heating

plasma, ECR, ion

54

A. Vodopyanov, S. Golubev, I. Izotov, A. Mansfeld
IAP/RAS, Nizhny Novgorod, Russia
G. Yushkov
Institute of High Current Electronics, Tomsk, Russia

It is well known that one can reach high average charge of ions in the ECR plasma by increasing plasma density and decreasing neutral gas pressure. ECR discharge could be realized at very low gas pressure, but discharge startup takes longer time when gas pressure is low. So, it is impossible to realize ECR discharge with limited microwave heating pulse duration at gas pressure lower certain threshold value. This problem could be solved with help of trigger plasma, which should be ignited at low gas pressure in the trap with high magnetic field. This fore plasma could help to decrease ECR plasma startup time significantly and make it possible to realize ECR plasma at very low pressure in pulse operation regime. We suggest penning type discharge as a trigger discharge for fast startup of pulsed ECR plasma. Penning type discharge glows at as low pressure as needed. Discharge was realized in the simple mirror magnetic trap at pressure about 10^-5 mbar. Helium was used as an operating gas. Significant plasma density (about 10¹¹ cm^-3) was obtained at the moment just before microwave heating pulse started. Gyrotron radiation with frequency of 75 GHz, microwave power up to 200 kW and pulse duration up to 1 ms, was used for plasma heating. In the present work the fully striped helium ions were demonstrated, average charge of ions in the plasma was equal 2. Temporal evolution of charge state distribution was investigated. Charge state distribution over helium pressure was also studied.

Poster MOPOT008 [0.535 MB]

TUCOBK01

Preglow Phenomenon Origins and its Scaling for Ecris

plasma, ion, electron, ECR

87

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

Preglow effect investigation is one of topical directions of ECR ion sources development at present. Preglow is of interest for efficient short-pulsed multi-charged ion source creation. Particularly, such source of intense beams of short-living radioactive isotopes multi-charged ions is one of key elements in “Beta-Beam” European project [1]. Use of Preglow-generating regime of an ECRIS operation is a promising way of pulsed high-intense multi-charged ion beams production with much shorter edges in comparison with usual operation regime. The first theoretical investigations of Preglow phenomenon were performed in references [2,3]. Present work describes modified model of ECR discharge development in a magnetic trap of the ECRIS as a continuation of [2,3]. Numerical simulations made with the updated model allow authors to propose more physical and intuitive explanation of Preglow phenomenon origins. Obtained dependences of Preglow characteristics on experimental conditions offer a scaling for a wide range of ECRISes.
[1] (ONLINE) http://beta-beam.web.cern.ch/beta-beam/task/diverse/mandate.htm
[2] T. Thuillier et al, Rev. of Sci. Instrum., 79, 02A314, 2008.
[3] I. Izotov et al, IEEE Trans. Plasma Sci. 36, 1494, 2008.

Slides TUCOBK01 [0.928 MB]

TUCOBK02

“Preglow” Investigation in ECR Discharge at 37 GHz, 100 kW

ion, plasma, ECR, ion-source

90

V. Skalyga, I. Izotov, S. Razin, V. Sidorov, V. Zorin
IAP/RAS, Nizhny Novgorod, Russia
T. Lamy, T. Thuillier
LPSC, Grenoble, France

Multicharged ion beams generation in "Preglow" regime is now considered as the main way of short pulsed ion source creation for “Beta Beam” project. The "Preglow" effect has been investigated at a several laboratories (LPSC, JYFL, IAP RAS). The effect was discovered at LPSC on PHOENIX ion source using 18 GHz radiation for plasma heating. Investigations at 14 GHz frequency were made at JYFL. Theoretical analysis demonstrated the advantage of MW frequency increase. Theoretical calculations predict possibility of "Preglow" peaks generation with duration about tens microseconds and rather high average ion charge. At present time at LPSC a joint construction of a new generation ECR ion source with 60 GHz gyrotron plasma heating is running. As a continuation of previous research at 14, 18 and 28 GHz at present work results of experimental and theoretical "Preglow" effect investigations at SMIS 37 setup with 37,5 GHz MW plasma heating are reported. Received data are important as fundamental result in physics of ECRISs and at the same time it is the next step on the way of 60 GHz SEISM facility creation. “Preglow” effect was observed and investigated in experiments with ECR discharge stimulated with gyrotron radiation @ 37.5 GHz, 100 kW. Received dependencies of the “Preglow” parameters are in good correspondence with results of numerical simulations. It was shown in experiments that generation of “Preglow” peak with duration about 30 μs is possible.

Slides TUCOBK02 [2.338 MB]

TUPOT009

Measurements of Bremsstrahlung Radiation and X-Ray Heat Load to Cryostat on SECRAL

ion, electron, ECR, plasma

134

H. Zhao, Y. Cao, X.X. Li, D. Xie, W.H. Zhang, X.Z. Zhang, H.W. Zhao, Y.H. Zhu
IMP, Lanzhou, People's Republic of China
W. Lu
Graduate School of the Chinese Academy of Sciences, Beijing, People's Republic of China

Measurement of Bremsstrahlung radiation from ECR plasma can yield certain information of the ECR heating process and a plausible estimate of the X-ray heat load to the cryostat of a superconducting ECR source which needs seriously addressed. With a newly-developed collimation system, which defines a narrower spatial range of the measurement and provides an effective shielding from the background, a systematic measurement of the Bremmstrahlung emitted axially from the SECRAL (Superconducting ECR Ion Source with Advanced design in Lanzhou) plasma were carried out recently. The spectral temperature Tspe, a relative index of mean energy of the plasma hot electrons, was derived through linear fitting of the spectra in semi-logarithm coordinates. This article will present and discuss the evolutions of the X-ray flux and the hot electron energy with various source parameters, such as heating frequency, RF power and magnetic field configuration. And possible solutions to reduce the X-ray heat load induced by Bremsstrahlung radiation are proposed and discussed.

Poster TUPOT009 [1.581 MB]

WECOAK04

Bremsstrahlung and Ion Beam Current Measurements With SuSI ECR Ion Source

plasma, collimation, ion, extraction

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]