You need JavaScript to view this

Onset of ELMs in JT-60U

Technical Report:

Abstract

The ELMs limiting the energy confinement in JT-60U appear when the heating power is high enough compared to the threshold power for the L-H transition. The ELM-free phase is observed when n-bar{sub e} is lower than the threshold density n-bar{sub e}{sup th}. The threshold density n-bar{sub e}{sup th} increases with (B{sub t}{sup 2}/(Rq{sub eff}{sup 2}))l{sub i} which is a measure parameter for the ballooning stability, where q{sub eff} is the effective safety factor at the edge. The edge pressure gradient estimated by n-bar{sub e}{sup th} T{sub i} (95%)/(T{sub i} (95%){sup 0.5}/B{sub p} (a)) is proportional to (B{sub t}{sup 2}/(Rq{sub eff}{sup 2}))l{sub i} which allows us to understand that the ELMs are related to the ballooning instability. A time dependent analysis of the evolution of pressure and current profiles including the boot-strap current shows that the steep edge pressure gradient is close to the marginal value for the high-n ideal ballooning instability at the onset of ELMs. (author).
Authors:
Kamada, Yutaka; Sato, Masayasu; Kikuchi, Mitsuru; Mori, Masahiro [1] 
  1. Japan Atomic Energy Research Inst., Naka, Ibaraki (Japan). Naka Fusion Research Establishment
Publication Date:
Aug 01, 1994
Product Type:
Technical Report
Report Number:
JAERI-Research-94-011
Reference Number:
SCA: 700340; PA: JPN-94:012117; EDB-95:026320; SN: 95001319925
Resource Relation:
Other Information: PBD: Aug 1994
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; JT-60U TOKAMAK; EDGE LOCALIZED MODES; H-MODE PLASMA CONFINEMENT; BALLOONING INSTABILITY; BOOTSTRAP CURRENT; PLASMA RADIAL PROFILES; BETA RATIO; 700340; PLASMA WAVES, OSCILLATIONS, AND INSTABILITIES
OSTI ID:
10109249
Research Organizations:
Japan Atomic Energy Research Inst., Tokyo (Japan)
Country of Origin:
Japan
Language:
English
Other Identifying Numbers:
Other: ON: DE95737209; TRN: JP9412117
Availability:
OSTI; NTIS; INIS
Submitting Site:
JPN
Size:
22 p.
Announcement Date:
Jun 30, 2005

Technical Report:

Citation Formats

Kamada, Yutaka, Sato, Masayasu, Kikuchi, Mitsuru, and Mori, Masahiro. Onset of ELMs in JT-60U. Japan: N. p., 1994. Web.
Kamada, Yutaka, Sato, Masayasu, Kikuchi, Mitsuru, & Mori, Masahiro. Onset of ELMs in JT-60U. Japan.
Kamada, Yutaka, Sato, Masayasu, Kikuchi, Mitsuru, and Mori, Masahiro. 1994. "Onset of ELMs in JT-60U." Japan.
@misc{etde_10109249,
title = {Onset of ELMs in JT-60U}
author = {Kamada, Yutaka, Sato, Masayasu, Kikuchi, Mitsuru, and Mori, Masahiro}
abstractNote = {The ELMs limiting the energy confinement in JT-60U appear when the heating power is high enough compared to the threshold power for the L-H transition. The ELM-free phase is observed when n-bar{sub e} is lower than the threshold density n-bar{sub e}{sup th}. The threshold density n-bar{sub e}{sup th} increases with (B{sub t}{sup 2}/(Rq{sub eff}{sup 2}))l{sub i} which is a measure parameter for the ballooning stability, where q{sub eff} is the effective safety factor at the edge. The edge pressure gradient estimated by n-bar{sub e}{sup th} T{sub i} (95%)/(T{sub i} (95%){sup 0.5}/B{sub p} (a)) is proportional to (B{sub t}{sup 2}/(Rq{sub eff}{sup 2}))l{sub i} which allows us to understand that the ELMs are related to the ballooning instability. A time dependent analysis of the evolution of pressure and current profiles including the boot-strap current shows that the steep edge pressure gradient is close to the marginal value for the high-n ideal ballooning instability at the onset of ELMs. (author).}
place = {Japan}
year = {1994}
month = {Aug}
}