Improvement of plasma confinement during lower-hybrid current drive

Uehara, Kazuya; Seki, Masami; Moriyama, Shinichi; Oyama, Naoyuki; Isayama, Akihiko; Kubo, Hirotaka

In the lower-hybrid current drive experiment for aiming the stationary operation in tokamaks another improved confinement mode to be suppressed the anomalous transport were observed in JT-60, TRIUM-1M and so on. In JT-60, the lower-hybrid current drive experiment by injecting two waves having different frequency the improved confinement like the H mode was found with extremely lower threshold power and in the JT-60U the more efficient electron heating in the core plasma region was found at the negative shear current profile with extremely lower injected power. Considering the physical mechanism of these improved confinement modes of the lower-hybrid current drive experiment some simple calculations are performed to be compared for the experimental results.