Recent experimental and analytic progress in the Japan Atomic Energy Research Institute Tokamak-60 Upgrade with W-shaped divertor configuration

The Japan Atomic Energy Research Institute (JAERI) completed the divertor modification of the JAERI Tokamak-60 Upgrade (JT-60U) [Y. Koide and the JT-60 Team, Phys. Plasmas 4, 1623 (1997)] in June, 1997, and experiments with the W-shaped pumped divertor have been carried out. The helium exhaust was demonstrated in the steady state by using helium neutral beam injection (NBI). The ratio of the effective particle confinement time of helium to the energy confinement time, τHe*/τE, became about 4 and the obtained enrichment factor of helium in the divertor was about 1. The high confinement mode (H-mode) plasma with edge localized mode (ELM) was sustained for 9 s with a confinement–enhancement factor (H factor) of ∼1.7. No increase of recycling and carbon impurity density was observed with the integrated NBI input energy of 203 MJ. In the reversed shear (RS) experiments, a quasi-steady-state ELMy H mode was achieved with an H factor ∼2.4. The stability of high-n toroidal drift modes was analyzed in the RS plasm...

[1]  W. Heidbrink.  Beam-driven chirping instability in DIII-D , 1995 .

[2]  M. S. Chance,et al.  Electromagnetic kinetic toroidal eigenmodes for general magnetohydrodynamic equilibria , 1982 .

[3]  G. Rewoldt,et al.  Microinstability properties of small‐aspect‐ratio tokamaks , 1996 .

[4]  Kubo,et al.  Helium ash exhaust studies with core fueling by a helium beam: L-mode divertor discharges with neutral-beam heating in the JT-60 tokamak. , 1991, Physical review letters.

[5]  Paul,et al.  Excitation of toroidal Alfvén eigenmodes in TFTR. , 1991, Physical review letters.

[6]  W. Horton,et al.  Theory of self‐organized critical transport in tokamak plasmas , 1996 .

[7]  Keiji Tani,et al.  Effect of Toroidal Field Ripple on Fast Ion Behavior in a Tokamak , 1981 .

[8]  Yoshihiko Koide,et al.  Progress in confinement and stability with plasma shape and profile control for steady-state operation in the Japan Atomic Energy Research Institute Tokamak-60 Upgrade , 1997 .

[9]  G. Rewoldt,et al.  Toroidal microinstability studies of high‐temperature tokamaks , 1990 .

[10]  Hiroshi Shirai,et al.  Degradation of energy and particle confinement in high-density ELMy H-mode plasmas on JT-60U , 1997 .

[11]  T. Fujita,et al.  Internal Transport Barrier for Electrons in JT-60U Reversed Shear Discharges , 1997 .

[12]  M. Chu,et al.  Stability of neutral beam driven TAE modes in DIII-D , 1993 .

[13]  T. Hahm,et al.  Role of flow shear in enhanced core confinement regimes , 1996 .

[14]  R. Budny,et al.  ACHIEVEMENT OF HIGH FUSION PERFORMANCE IN JT-60U REVERSED SHEAR DISCHARGES , 1997 .

[15]  M. Kikuchi,et al.  Experimental evidence for the bootstrap current in a tokamak , 1995 .