Strong electron heating in CHS ICRF heating experiments

S. Masuda; R. Kumazawa; K. Nishimura; T. Mutoh; T. Watari; F. Simbo; T. Seki; T. Ido; R. Akiyama; A. Ando; A. Ejiri; H. Idei; K. Ida; H. Iguchi; M. Isobe; M. Iwase; S. Kubo; K. Matsuoka; T. Morisaki; S. Morita; S. Mutoh; S. Murakami; S. Okamura; T. Ozaki; S. Sakakibara; M. Sasao; C. Takahashi; T. Kawamoto; K. Tanaka; J. Xu; H. Yamada; I. Yamada; D. A. Rasmussen; J. F. Lyon; J. B. Wilgen; D. E. Greenwood; D. J. Hoffman; E. F. Jaeger; M. Murakami

doi:10.1088/0029-5515/37/1/I12

Strong electron heating in CHS ICRF heating experiments

S. Masuda, R. Kumazawa, K. Nishimura, T. Mutoh, T. Watari, F. Simbo, T. Seki, T. Ido, R. Akiyama, A. Ando, A. Ejiri, H. Idei, K. Ida, H. Iguchi, M. Isobe, M. Iwase, S. Kubo, K. Matsuoka, T. Morisaki, S. MoritaS. Mutoh, S. Murakami, S. Okamura, T. Ozaki, S. Sakakibara, M. Sasao, C. Takahashi, T. Kawamoto, K. Tanaka, J. Xu, H. Yamada, I. Yamada, D. A. Rasmussen, J. F. Lyon, J. B. Wilgen, D. E. Greenwood, D. J. Hoffman, E. F. Jaeger, M. Murakami

Research output: Contribution to journal › Article › peer-review

24 Citations (Scopus)

Abstract

An ion cyclotron range of frequencies (ICRF) heating experiment was performed on the Compact Helical System (CHS) device in order to identify the problems in establishing this as a reliable heating method. Radiofrequency heating was applied to plasmas with two ion species produced by ECH. Stored energy increased up to 2.2 kJ with the application of a 590 kW ICRF heating pulse, giving a heating efficiency comparable to that of NBI heating. More importantly, the 'flat-top' of the stored energy was maintained during the pulse. Good heating was realized with 30% proton and 70% deuteron plasmas at high density (4 ×¹⁹ m^-3). It was found that the best discharges are dominated by electron ICRF heating, which seems to be the reason for the successful results. On the contrary, a flat-top in stored energy has never been obtained in discharges where ion heating dominates. The loss of high energy ions with large pitch angles produced by ion heating appears to degrade the performance and limit the duration of the heating. A similar degradation was encountered in previous ICRF heating experiments in helical systems. A newly designed detector was used to study the loss of the helically trapped particles.

Original language	English
Pages (from-to)	53-68
Number of pages	16
Journal	Nuclear Fusion
Volume	37
Issue number	1
DOIs	https://doi.org/10.1088/0029-5515/37/1/I12
Publication status	Published - 1997 Jan
Externally published	Yes

ASJC Scopus subject areas

Nuclear and High Energy Physics
Condensed Matter Physics

Access to Document

10.1088/0029-5515/37/1/I12

Cite this

Masuda, S., Kumazawa, R., Nishimura, K., Mutoh, T., Watari, T., Simbo, F., Seki, T., Ido, T., Akiyama, R., Ando, A., Ejiri, A., Idei, H., Ida, K., Iguchi, H., Isobe, M., Iwase, M., Kubo, S., Matsuoka, K., Morisaki, T., ... Murakami, M. (1997). Strong electron heating in CHS ICRF heating experiments. Nuclear Fusion, 37(1), 53-68. https://doi.org/10.1088/0029-5515/37/1/I12

Masuda, S, Kumazawa, R, Nishimura, K, Mutoh, T, Watari, T, Simbo, F, Seki, T, Ido, T, Akiyama, R, Ando, A, Ejiri, A, Idei, H, Ida, K, Iguchi, H, Isobe, M, Iwase, M, Kubo, S, Matsuoka, K, Morisaki, T, Morita, S, Mutoh, S, Murakami, S, Okamura, S, Ozaki, T, Sakakibara, S, Sasao, M, Takahashi, C, Kawamoto, T, Tanaka, K, Xu, J, Yamada, H, Yamada, I, Rasmussen, DA, Lyon, JF, Wilgen, JB, Greenwood, DE, Hoffman, DJ, Jaeger, EF & Murakami, M 1997, 'Strong electron heating in CHS ICRF heating experiments', Nuclear Fusion, vol. 37, no. 1, pp. 53-68. https://doi.org/10.1088/0029-5515/37/1/I12

@article{71cd9d5d46744164b44553211249b1d8,

title = "Strong electron heating in CHS ICRF heating experiments",

abstract = "An ion cyclotron range of frequencies (ICRF) heating experiment was performed on the Compact Helical System (CHS) device in order to identify the problems in establishing this as a reliable heating method. Radiofrequency heating was applied to plasmas with two ion species produced by ECH. Stored energy increased up to 2.2 kJ with the application of a 590 kW ICRF heating pulse, giving a heating efficiency comparable to that of NBI heating. More importantly, the 'flat-top' of the stored energy was maintained during the pulse. Good heating was realized with 30% proton and 70% deuteron plasmas at high density (4 ×19 m-3). It was found that the best discharges are dominated by electron ICRF heating, which seems to be the reason for the successful results. On the contrary, a flat-top in stored energy has never been obtained in discharges where ion heating dominates. The loss of high energy ions with large pitch angles produced by ion heating appears to degrade the performance and limit the duration of the heating. A similar degradation was encountered in previous ICRF heating experiments in helical systems. A newly designed detector was used to study the loss of the helically trapped particles.",

author = "S. Masuda and R. Kumazawa and K. Nishimura and T. Mutoh and T. Watari and F. Simbo and T. Seki and T. Ido and R. Akiyama and A. Ando and A. Ejiri and H. Idei and K. Ida and H. Iguchi and M. Isobe and M. Iwase and S. Kubo and K. Matsuoka and T. Morisaki and S. Morita and S. Mutoh and S. Murakami and S. Okamura and T. Ozaki and S. Sakakibara and M. Sasao and C. Takahashi and T. Kawamoto and K. Tanaka and J. Xu and H. Yamada and I. Yamada and Rasmussen, {D. A.} and Lyon, {J. F.} and Wilgen, {J. B.} and Greenwood, {D. E.} and Hoffman, {D. J.} and Jaeger, {E. F.} and M. Murakami",

year = "1997",

month = jan,

doi = "10.1088/0029-5515/37/1/I12",

language = "English",

volume = "37",

pages = "53--68",

journal = "Nuclear Fusion",

issn = "0029-5515",

publisher = "IOP Publishing Ltd.",

number = "1",

}

TY - JOUR

T1 - Strong electron heating in CHS ICRF heating experiments

AU - Masuda, S.

AU - Kumazawa, R.

AU - Nishimura, K.

AU - Mutoh, T.

AU - Watari, T.

AU - Simbo, F.

AU - Seki, T.

AU - Ido, T.

AU - Akiyama, R.

AU - Ando, A.

AU - Ejiri, A.

AU - Idei, H.

AU - Ida, K.

AU - Iguchi, H.

AU - Isobe, M.

AU - Iwase, M.

AU - Kubo, S.

AU - Matsuoka, K.

AU - Morisaki, T.

AU - Morita, S.

AU - Mutoh, S.

AU - Murakami, S.

AU - Okamura, S.

AU - Ozaki, T.

AU - Sakakibara, S.

AU - Sasao, M.

AU - Takahashi, C.

AU - Kawamoto, T.

AU - Tanaka, K.

AU - Xu, J.

AU - Yamada, H.

AU - Yamada, I.

AU - Rasmussen, D. A.

AU - Lyon, J. F.

AU - Wilgen, J. B.

AU - Greenwood, D. E.

AU - Hoffman, D. J.

AU - Jaeger, E. F.

AU - Murakami, M.

PY - 1997/1

Y1 - 1997/1

N2 - An ion cyclotron range of frequencies (ICRF) heating experiment was performed on the Compact Helical System (CHS) device in order to identify the problems in establishing this as a reliable heating method. Radiofrequency heating was applied to plasmas with two ion species produced by ECH. Stored energy increased up to 2.2 kJ with the application of a 590 kW ICRF heating pulse, giving a heating efficiency comparable to that of NBI heating. More importantly, the 'flat-top' of the stored energy was maintained during the pulse. Good heating was realized with 30% proton and 70% deuteron plasmas at high density (4 ×19 m-3). It was found that the best discharges are dominated by electron ICRF heating, which seems to be the reason for the successful results. On the contrary, a flat-top in stored energy has never been obtained in discharges where ion heating dominates. The loss of high energy ions with large pitch angles produced by ion heating appears to degrade the performance and limit the duration of the heating. A similar degradation was encountered in previous ICRF heating experiments in helical systems. A newly designed detector was used to study the loss of the helically trapped particles.

AB - An ion cyclotron range of frequencies (ICRF) heating experiment was performed on the Compact Helical System (CHS) device in order to identify the problems in establishing this as a reliable heating method. Radiofrequency heating was applied to plasmas with two ion species produced by ECH. Stored energy increased up to 2.2 kJ with the application of a 590 kW ICRF heating pulse, giving a heating efficiency comparable to that of NBI heating. More importantly, the 'flat-top' of the stored energy was maintained during the pulse. Good heating was realized with 30% proton and 70% deuteron plasmas at high density (4 ×19 m-3). It was found that the best discharges are dominated by electron ICRF heating, which seems to be the reason for the successful results. On the contrary, a flat-top in stored energy has never been obtained in discharges where ion heating dominates. The loss of high energy ions with large pitch angles produced by ion heating appears to degrade the performance and limit the duration of the heating. A similar degradation was encountered in previous ICRF heating experiments in helical systems. A newly designed detector was used to study the loss of the helically trapped particles.

UR - http://www.scopus.com/inward/record.url?scp=0030733751&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0030733751&partnerID=8YFLogxK

U2 - 10.1088/0029-5515/37/1/I12

DO - 10.1088/0029-5515/37/1/I12

M3 - Article

AN - SCOPUS:0030733751

SN - 0029-5515

VL - 37

SP - 53

EP - 68

JO - Nuclear Fusion

JF - Nuclear Fusion

IS - 1

ER -

Strong electron heating in CHS ICRF heating experiments

Abstract

ASJC Scopus subject areas

Access to Document

Other files and links

Fingerprint

Cite this