First plasma experiment on spherical tokamak device UTST

Ryota Imazawa, Makoto Nakagawa, Shuji Kamio, Ryuma Hihara, Takuma Yamada, Michiaki Inomoto, Yuichi Takase, Yasushi Ono

Research output: Contribution to journalArticle

2 Citations (Scopus)

Abstract

The UTST (University of Tokyo Spherical Tokamak) device was constructed for the purpose of exploring the formation of ultrahigh-beta ST (spherical tokamak) plasma using the double null plasma merging method. When two plasmas merge together to form a single plasma, magnetic field lines reconnect, and magnetic field energy is converted to plasma kinetic energy, increasing the plasma beta. Merging start-up has been demonstrated in the TS-3/4, START, and MAST devices using coils inside the vacuum vessel, and the TS-3 plasma obtained a 50% beta. In order to demonstrate start-up in a more reactor-relevant situation, UTST has all poloidal field (PF) coils outside the vacuum vessel. The first plasma experiment on the UTST was begun in December 2007. In the results, the plasma obtained 10 kA by using only the outer PF coils and a single ST was generated in the lower area (z = -0.3 to -1.0 m) close to a washer gun. This result suggests that another washer gun on the top of the UTST can allow the generation of ST in the upper area and merging start-up by using outer PF coils.

Original languageEnglish
Pages (from-to)20-26
Number of pages7
JournalElectrical Engineering in Japan (English translation of Denki Gakkai Ronbunshi)
Volume179
Issue number2
DOIs
Publication statusPublished - Apr 30 2012
Externally publishedYes

Fingerprint

Tokamak devices
Plasmas
Experiments
Merging
Washers
Vacuum
Magnetic fields
Kinetic energy

All Science Journal Classification (ASJC) codes

  • Electrical and Electronic Engineering
  • Energy Engineering and Power Technology

Cite this

First plasma experiment on spherical tokamak device UTST. / Imazawa, Ryota; Nakagawa, Makoto; Kamio, Shuji; Hihara, Ryuma; Yamada, Takuma; Inomoto, Michiaki; Takase, Yuichi; Ono, Yasushi.

In: Electrical Engineering in Japan (English translation of Denki Gakkai Ronbunshi), Vol. 179, No. 2, 30.04.2012, p. 20-26.

Research output: Contribution to journalArticle

Imazawa, Ryota ; Nakagawa, Makoto ; Kamio, Shuji ; Hihara, Ryuma ; Yamada, Takuma ; Inomoto, Michiaki ; Takase, Yuichi ; Ono, Yasushi. / First plasma experiment on spherical tokamak device UTST. In: Electrical Engineering in Japan (English translation of Denki Gakkai Ronbunshi). 2012 ; Vol. 179, No. 2. pp. 20-26.
@article{ec2643e9b0ef499ba45d141da1dd95e7,
title = "First plasma experiment on spherical tokamak device UTST",
abstract = "The UTST (University of Tokyo Spherical Tokamak) device was constructed for the purpose of exploring the formation of ultrahigh-beta ST (spherical tokamak) plasma using the double null plasma merging method. When two plasmas merge together to form a single plasma, magnetic field lines reconnect, and magnetic field energy is converted to plasma kinetic energy, increasing the plasma beta. Merging start-up has been demonstrated in the TS-3/4, START, and MAST devices using coils inside the vacuum vessel, and the TS-3 plasma obtained a 50{\%} beta. In order to demonstrate start-up in a more reactor-relevant situation, UTST has all poloidal field (PF) coils outside the vacuum vessel. The first plasma experiment on the UTST was begun in December 2007. In the results, the plasma obtained 10 kA by using only the outer PF coils and a single ST was generated in the lower area (z = -0.3 to -1.0 m) close to a washer gun. This result suggests that another washer gun on the top of the UTST can allow the generation of ST in the upper area and merging start-up by using outer PF coils.",
author = "Ryota Imazawa and Makoto Nakagawa and Shuji Kamio and Ryuma Hihara and Takuma Yamada and Michiaki Inomoto and Yuichi Takase and Yasushi Ono",
year = "2012",
month = "4",
day = "30",
doi = "10.1002/eej.21216",
language = "English",
volume = "179",
pages = "20--26",
journal = "Electrical Engineering in Japan (English translation of Denki Gakkai Ronbunshi)",
issn = "0424-7760",
publisher = "John Wiley and Sons Inc.",
number = "2",

}

TY - JOUR

T1 - First plasma experiment on spherical tokamak device UTST

AU - Imazawa, Ryota

AU - Nakagawa, Makoto

AU - Kamio, Shuji

AU - Hihara, Ryuma

AU - Yamada, Takuma

AU - Inomoto, Michiaki

AU - Takase, Yuichi

AU - Ono, Yasushi

PY - 2012/4/30

Y1 - 2012/4/30

N2 - The UTST (University of Tokyo Spherical Tokamak) device was constructed for the purpose of exploring the formation of ultrahigh-beta ST (spherical tokamak) plasma using the double null plasma merging method. When two plasmas merge together to form a single plasma, magnetic field lines reconnect, and magnetic field energy is converted to plasma kinetic energy, increasing the plasma beta. Merging start-up has been demonstrated in the TS-3/4, START, and MAST devices using coils inside the vacuum vessel, and the TS-3 plasma obtained a 50% beta. In order to demonstrate start-up in a more reactor-relevant situation, UTST has all poloidal field (PF) coils outside the vacuum vessel. The first plasma experiment on the UTST was begun in December 2007. In the results, the plasma obtained 10 kA by using only the outer PF coils and a single ST was generated in the lower area (z = -0.3 to -1.0 m) close to a washer gun. This result suggests that another washer gun on the top of the UTST can allow the generation of ST in the upper area and merging start-up by using outer PF coils.

AB - The UTST (University of Tokyo Spherical Tokamak) device was constructed for the purpose of exploring the formation of ultrahigh-beta ST (spherical tokamak) plasma using the double null plasma merging method. When two plasmas merge together to form a single plasma, magnetic field lines reconnect, and magnetic field energy is converted to plasma kinetic energy, increasing the plasma beta. Merging start-up has been demonstrated in the TS-3/4, START, and MAST devices using coils inside the vacuum vessel, and the TS-3 plasma obtained a 50% beta. In order to demonstrate start-up in a more reactor-relevant situation, UTST has all poloidal field (PF) coils outside the vacuum vessel. The first plasma experiment on the UTST was begun in December 2007. In the results, the plasma obtained 10 kA by using only the outer PF coils and a single ST was generated in the lower area (z = -0.3 to -1.0 m) close to a washer gun. This result suggests that another washer gun on the top of the UTST can allow the generation of ST in the upper area and merging start-up by using outer PF coils.

UR - http://www.scopus.com/inward/record.url?scp=84856304325&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84856304325&partnerID=8YFLogxK

U2 - 10.1002/eej.21216

DO - 10.1002/eej.21216

M3 - Article

VL - 179

SP - 20

EP - 26

JO - Electrical Engineering in Japan (English translation of Denki Gakkai Ronbunshi)

JF - Electrical Engineering in Japan (English translation of Denki Gakkai Ronbunshi)

SN - 0424-7760

IS - 2

ER -