Effect of halo current and its toroidal asymmetry during disruptions in JT-60U

Journal Article · Wed Nov 01 04:00:00 EST 1995 · Fusion Technology

OSTI ID:159668

Neyatani, Y; Yoshino, R; Ando, T ^[1]

---

1. Japan Atomic Energy Research Inst., Naka machi (Japan)

A poloidal halo current due to a vertical displacement event (VDE) is observed in experimentally simulated VDE discharges and density limit disruptions in the JT-60U tokamak. In the case of a clockwise I{sub p} and B{sub T} discharge, the halo current flows into the vacuum vessel from the inside separatrix and goes back to the plasma from the outside separatrix. A maximum halo current is produced by a change in the poloidal flux generated by plasma current decay. A toroidal asymmetry factor of 2.5 is estimated from the requirements of the fracture of the carbon-fiber composite tiles. The toroidal asymmetry is caused by the poloidal field (PF) that is produced by the toroidal field (TF) ripple, the deformation of the vacuum vessel, the setting error between the vacuum vessel and the TF and PF coils, the low-n mode during current quench, etc. To consider this asymmetry, in JT-60U, one must estimate the total halo current as nearly 26% of the plasma current just before a current quench. 25 refs., 10 figs.

• OSTI ID: 159668
• Journal Information: Fusion Technology, Journal Name: Fusion Technology Journal Issue: 4 Vol. 28; ISSN 0748-1896; ISSN FUSTE8
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
ASYMMETRY
CURRENTS
JT-60 TOKAMAK
PLASMA DENSITY
PLASMA DISRUPTION
TOKAMAK TYPE REACTORS
TOROIDAL CONFIGURATION