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Effect of the magnetic field strength on the argon plasma characteristics of a helicon plasma source with a two-turn flat-loop antenna

Part of: Open Magnetic Systems for Plasma Confinement

Published online by Cambridge University Press:  20 September 2024

Takumi Seto Open the ORCID record for Takumi Seto [Opens in a new window] ,
Naomichi Ezumi Open the ORCID record for Naomichi Ezumi [Opens in a new window] ,
Reina Miyauchi ,
Takuma Okamoto Open the ORCID record for Takuma Okamoto [Opens in a new window] ,
Satoshi Takahashi ,
Kosuke Takanashi ,
Keishi Kouno ,
Hiroto Kawahara ,
Mafumi Hirata  and
Junko Kohagura
...Show all authors
Takumi Seto*
Affiliation:
Plasma Research Center, University of Tsukuba, Tsukuba, Ibaraki 305-8577, Japan
Naomichi Ezumi
Affiliation:
Plasma Research Center, University of Tsukuba, Tsukuba, Ibaraki 305-8577, Japan
Reina Miyauchi
Affiliation:
Plasma Research Center, University of Tsukuba, Tsukuba, Ibaraki 305-8577, Japan
Takuma Okamoto
Affiliation:
Plasma Research Center, University of Tsukuba, Tsukuba, Ibaraki 305-8577, Japan
Satoshi Takahashi
Affiliation:
Plasma Research Center, University of Tsukuba, Tsukuba, Ibaraki 305-8577, Japan
Kosuke Takanashi
Affiliation:
Plasma Research Center, University of Tsukuba, Tsukuba, Ibaraki 305-8577, Japan
Keishi Kouno
Affiliation:
Plasma Research Center, University of Tsukuba, Tsukuba, Ibaraki 305-8577, Japan
Hiroto Kawahara
Affiliation:
Plasma Research Center, University of Tsukuba, Tsukuba, Ibaraki 305-8577, Japan
Mafumi Hirata
Affiliation:
Plasma Research Center, University of Tsukuba, Tsukuba, Ibaraki 305-8577, Japan
Junko Kohagura
Affiliation:
Plasma Research Center, University of Tsukuba, Tsukuba, Ibaraki 305-8577, Japan
Satoshi Togo
Affiliation:
Plasma Research Center, University of Tsukuba, Tsukuba, Ibaraki 305-8577, Japan
Mizuki Sakamoto
Affiliation:
Plasma Research Center, University of Tsukuba, Tsukuba, Ibaraki 305-8577, Japan
Takeru Furukawa
Affiliation:
Kobe University, Kobe, Hyogo 657-8501, Japan
Shunjiro Shinohara
Affiliation:
Tokyo University of Agriculture and Technology, Koganei, Tokyo 184-8588, Japan
*
†Email address for correspondence: [email protected]
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Abstract

New plasma applications in advanced fields, such as fundamental nuclear fusion research, require high-density, large-diameter plasma with a strong and non-uniform magnetic field. A helicon plasma (HP) source using a flat-type antenna is expected to be one of the promising methods for such applications. In this study, we developed an HP source with a two-turn flat-loop antenna connected to a 30 kW radio frequency power supply in the Compact Test Plasma device. In the argon plasma generation experiment with various magnetic fields, HP generation was observed for the first time in this device. The electron density was calculated from the dispersion relation with the magnetic field strength at 45 cm from the antenna surface, assuming a fundamental radial mode and an azimuthal mode of $m=0$. The electron density expected from the experimental result was approximately in the same range as the calculation result by a factor of 2.3 to 3.5. In addition, the magnetic field strength and shape around the antenna are important factors in the plasma properties. This plasma source has been installed in the pilot GAMMA PDX-SC, which is under development for nuclear plasma research, and it contributes to the study of the HP generation process.

Keywords

plasma applicationselectric dischargesplasma devices
Type
Research Article
Information
Journal of Plasma Physics , Volume 90 , Issue 4 , August 2024 , 975900401
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Copyright
Copyright © The Author(s), 2024. Published by Cambridge University Press

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