Kenmochi N, Minami T, Takahashi C, Tei S, Mizuuchi T, Kobayashi S, Nagasaki K, Nakamura Y, Okada H, Kado S, Yamamoto S, Ohshima S, Konoshima S, Shi N, Zang L, Ohtani Y, Kasajima K, Sano F
Graduate School of Energy Science, Kyoto University, Gokasho, Uji 611-0011, Japan.
Institute of Advanced Energy, Kyoto University, Gokasho, Uji 611-0011, Japan.
Rev Sci Instrum. 2014 Nov;85(11):11D819. doi: 10.1063/1.4890255.
A Nd:YAG Thomson scattering system has been developed for Heliotron J. The system consists of two 550 mJ 50 Hz lasers, large collection optics, and 25 radial channel (∼1 cm spatial resolution) interference polychromators. This measurement system achieves a S/N ratio of ∼50 for low-density plasma (ne ∼ 0.5 × 10(19) m(-3)). A time evolution of electron temperature profiles was measured with this system for a high-intensity gas-puff (HIGP) fueling neutral-beam-injection plasma. The peripheral temperature of the higher-density phase after HIGP recovers to the low-density pre-HIGP level, suggesting that improving particle transport in the HIGP plasma may be possible.