Synergistic effect of nitrogen and hydrogen seeding gases on plasma detachment in the GAMMA 10/PDX tandem mirror

N. Ezumi; T. Iijima; M. Sakamoto; Y. Nakashima; M. Hirata; M. Ichimura; R. Ikezoe; T. Imai; T. Kariya; I. Katanuma; J. Kohagura; R. Minami; T. Numakura; M. Yoshikawa; S. Togo; M. S. Islam; M. M. Islam; K. Nojiri; A. Terakado; S. Jang; Y. Kinoshita; T. Mikami; S. Yamashita; T. Yoshimoto; T. Hara; A. Hatayama; K. Ichimura; S. Kado; S. Masuzaki; T. Nakano; N. Ohno; S. Sawada; H. Tanaka; A. Tonegawa; R. Perillo

doi:10.1088/1741-4326/ab1a4a

Synergistic effect of nitrogen and hydrogen seeding gases on plasma detachment in the GAMMA 10/PDX tandem mirror

N. Ezumi, T. Iijima, M. Sakamoto, Y. Nakashima, M. Hirata, M. Ichimura, R. Ikezoe, T. Imai, T. Kariya, I. Katanuma, J. Kohagura, R. Minami, T. Numakura, M. Yoshikawa, S. Togo, M. S. Islam, M. M. Islam, K. Nojiri, A. Terakado, S. JangY. Kinoshita, T. Mikami, S. Yamashita, T. Yoshimoto, T. Hara, A. Hatayama, K. Ichimura, S. Kado, S. Masuzaki, T. Nakano, N. Ohno, S. Sawada, H. Tanaka, A. Tonegawa, R. Perillo

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

20 Scopus citations

Abstract

We have investigated the synergistic effect of a combination of various impurity gases and hydrogen gas on plasma detachment of high temperature plasma, equivalent to scrape-off layer plasma of tokamaks in the GAMMA 10/PDX end region, utilizing an open magnetic field configuration. A small puff of an impurity gas (N₂, Ne, Ar, Kr, Xe) in combination with a puff of H₂ gas is examined to evaluate their synergistic effect on the formation of detached plasma; the following results are obtained. (i) A combination of N₂ and H₂ puffs showed a clear decrease of electron density and ion flux; (ii) N₂ and H₂ puffs form a strong density gradient along the axial direction; and (iii) other noble impurity gases showed an insufficient synergistic effect. The new results indicate the possibility of achieving a reliable divertor operation scheme and the importance of a deeper understanding of the H₂ and N₂ assisted recombination process.

Original language	English
Article number	066030
Journal	Nuclear Fusion
Volume	59
Issue number	6
DOIs	https://doi.org/10.1088/1741-4326/ab1a4a
State	Published - May 9 2019
Externally published	Yes

Keywords

N-MAR
divertor
hydrogen
nitrogen
plasma detachment

UN SDGs

This output contributes to the following UN Sustainable Development Goals (SDGs)

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10.1088/1741-4326/ab1a4a

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Ezumi, N., Iijima, T., Sakamoto, M., Nakashima, Y., Hirata, M., Ichimura, M., Ikezoe, R., Imai, T., Kariya, T., Katanuma, I., Kohagura, J., Minami, R., Numakura, T., Yoshikawa, M., Togo, S., Islam, M. S., Islam, M. M., Nojiri, K., Terakado, A., ... Perillo, R. (2019). Synergistic effect of nitrogen and hydrogen seeding gases on plasma detachment in the GAMMA 10/PDX tandem mirror. Nuclear Fusion, 59(6), Article 066030. https://doi.org/10.1088/1741-4326/ab1a4a

@article{3771272c67854147a082d7b6f347d8bc,

title = "Synergistic effect of nitrogen and hydrogen seeding gases on plasma detachment in the GAMMA 10/PDX tandem mirror",

abstract = "We have investigated the synergistic effect of a combination of various impurity gases and hydrogen gas on plasma detachment of high temperature plasma, equivalent to scrape-off layer plasma of tokamaks in the GAMMA 10/PDX end region, utilizing an open magnetic field configuration. A small puff of an impurity gas (N2, Ne, Ar, Kr, Xe) in combination with a puff of H2 gas is examined to evaluate their synergistic effect on the formation of detached plasma; the following results are obtained. (i) A combination of N2 and H2 puffs showed a clear decrease of electron density and ion flux; (ii) N2 and H2 puffs form a strong density gradient along the axial direction; and (iii) other noble impurity gases showed an insufficient synergistic effect. The new results indicate the possibility of achieving a reliable divertor operation scheme and the importance of a deeper understanding of the H2 and N2 assisted recombination process.",

keywords = "N-MAR, divertor, hydrogen, nitrogen, plasma detachment",

author = "N. Ezumi and T. Iijima and M. Sakamoto and Y. Nakashima and M. Hirata and M. Ichimura and R. Ikezoe and T. Imai and T. Kariya and I. Katanuma and J. Kohagura and R. Minami and T. Numakura and M. Yoshikawa and S. Togo and Islam, {M. S.} and Islam, {M. M.} and K. Nojiri and A. Terakado and S. Jang and Y. Kinoshita and T. Mikami and S. Yamashita and T. Yoshimoto and T. Hara and A. Hatayama and K. Ichimura and S. Kado and S. Masuzaki and T. Nakano and N. Ohno and S. Sawada and H. Tanaka and A. Tonegawa and R. Perillo",

note = "Publisher Copyright: {\textcopyright} 2019 IAEA, Vienna.",

year = "2019",

month = may,

day = "9",

doi = "10.1088/1741-4326/ab1a4a",

language = "English",

volume = "59",

journal = "Nuclear Fusion",

issn = "0029-5515",

publisher = "IOP Publishing",

number = "6",

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Ezumi, N, Iijima, T, Sakamoto, M, Nakashima, Y, Hirata, M, Ichimura, M, Ikezoe, R, Imai, T, Kariya, T, Katanuma, I, Kohagura, J, Minami, R, Numakura, T, Yoshikawa, M, Togo, S, Islam, MS, Islam, MM, Nojiri, K, Terakado, A, Jang, S, Kinoshita, Y, Mikami, T, Yamashita, S, Yoshimoto, T, Hara, T, Hatayama, A, Ichimura, K, Kado, S, Masuzaki, S, Nakano, T, Ohno, N, Sawada, S, Tanaka, H, Tonegawa, A & Perillo, R 2019, 'Synergistic effect of nitrogen and hydrogen seeding gases on plasma detachment in the GAMMA 10/PDX tandem mirror', Nuclear Fusion, vol. 59, no. 6, 066030. https://doi.org/10.1088/1741-4326/ab1a4a

TY - JOUR

T1 - Synergistic effect of nitrogen and hydrogen seeding gases on plasma detachment in the GAMMA 10/PDX tandem mirror

AU - Ezumi, N.

AU - Iijima, T.

AU - Sakamoto, M.

AU - Nakashima, Y.

AU - Hirata, M.

AU - Ichimura, M.

AU - Ikezoe, R.

AU - Imai, T.

AU - Kariya, T.

AU - Katanuma, I.

AU - Kohagura, J.

AU - Minami, R.

AU - Numakura, T.

AU - Yoshikawa, M.

AU - Togo, S.

AU - Islam, M. S.

AU - Islam, M. M.

AU - Nojiri, K.

AU - Terakado, A.

AU - Jang, S.

AU - Kinoshita, Y.

AU - Mikami, T.

AU - Yamashita, S.

AU - Yoshimoto, T.

AU - Hara, T.

AU - Hatayama, A.

AU - Ichimura, K.

AU - Kado, S.

AU - Masuzaki, S.

AU - Nakano, T.

AU - Ohno, N.

AU - Sawada, S.

AU - Tanaka, H.

AU - Tonegawa, A.

AU - Perillo, R.

PY - 2019/5/9

Y1 - 2019/5/9

N2 - We have investigated the synergistic effect of a combination of various impurity gases and hydrogen gas on plasma detachment of high temperature plasma, equivalent to scrape-off layer plasma of tokamaks in the GAMMA 10/PDX end region, utilizing an open magnetic field configuration. A small puff of an impurity gas (N2, Ne, Ar, Kr, Xe) in combination with a puff of H2 gas is examined to evaluate their synergistic effect on the formation of detached plasma; the following results are obtained. (i) A combination of N2 and H2 puffs showed a clear decrease of electron density and ion flux; (ii) N2 and H2 puffs form a strong density gradient along the axial direction; and (iii) other noble impurity gases showed an insufficient synergistic effect. The new results indicate the possibility of achieving a reliable divertor operation scheme and the importance of a deeper understanding of the H2 and N2 assisted recombination process.

AB - We have investigated the synergistic effect of a combination of various impurity gases and hydrogen gas on plasma detachment of high temperature plasma, equivalent to scrape-off layer plasma of tokamaks in the GAMMA 10/PDX end region, utilizing an open magnetic field configuration. A small puff of an impurity gas (N2, Ne, Ar, Kr, Xe) in combination with a puff of H2 gas is examined to evaluate their synergistic effect on the formation of detached plasma; the following results are obtained. (i) A combination of N2 and H2 puffs showed a clear decrease of electron density and ion flux; (ii) N2 and H2 puffs form a strong density gradient along the axial direction; and (iii) other noble impurity gases showed an insufficient synergistic effect. The new results indicate the possibility of achieving a reliable divertor operation scheme and the importance of a deeper understanding of the H2 and N2 assisted recombination process.

KW - N-MAR

KW - divertor

KW - hydrogen

KW - nitrogen

KW - plasma detachment

UR - http://www.scopus.com/inward/record.url?scp=85067543975&partnerID=8YFLogxK

U2 - 10.1088/1741-4326/ab1a4a

DO - 10.1088/1741-4326/ab1a4a

M3 - Article

AN - SCOPUS:85067543975

SN - 0029-5515

VL - 59

JO - Nuclear Fusion

JF - Nuclear Fusion

IS - 6

M1 - 066030

ER -

Synergistic effect of nitrogen and hydrogen seeding gases on plasma detachment in the GAMMA 10/PDX tandem mirror

Abstract

Keywords

UN SDGs

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