First measurement of time evolution of electron temperature profiles with Nd:YAG Thomson scattering system on Heliotron J

N Kenmochi; T Minami; C Takahashi; S Tei; T Mizuuchi; S Kobayashi; K Nagasaki; Y Nakamura; H Okada; S Kado; S Yamamoto; S Ohshima; S Konoshima; N Shi; L Zang; Y Ohtani; K Kasajima; F Sano

doi:10.1063/1.4890255

First measurement of time evolution of electron temperature profiles with Nd:YAG Thomson scattering system on Heliotron J

Rev Sci Instrum. 2014 Nov;85(11):11D819. doi: 10.1063/1.4890255.

Authors

N Kenmochi¹, T Minami², C Takahashi², S Tei¹, T Mizuuchi², S Kobayashi², K Nagasaki², Y Nakamura², H Okada², S Kado², S Yamamoto², S Ohshima², S Konoshima², N Shi², L Zang¹, Y Ohtani¹, K Kasajima¹, F Sano²

Affiliations

¹ Graduate School of Energy Science, Kyoto University, Gokasho, Uji 611-0011, Japan.
² Institute of Advanced Energy, Kyoto University, Gokasho, Uji 611-0011, Japan.

PMID: 25430232
DOI: 10.1063/1.4890255

Abstract

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.