Sano Ryuichi, Homma Hiroto, Takechi Manabu, Nakano Tomohide
Naka Institute, National Institutes for Quantum Science and Technology, Naka 311-0193, Japan.
Rev Sci Instrum. 2024 Jul 1;95(7). doi: 10.1063/5.0215598.
A soft x-ray (SX) diagnostic system has been designed and installed in JT-60SA for the first plasma. For quantitative measurement, the etendue of each viewing chord was evaluated analytically and numerically. The electron temperature is evaluated from the detected bremsstrahlung emission ratio between two detector arrays with two different thicknesses of Be filters. The two filter thicknesses were optimized to be 7 and 50 μm for the expected electron temperature range of 0-3 keV. The one-dimensional profile of SX emission is reconstructed from line integrated emission by the elliptic Abel inversion scheme. For a plasma discharge with a plasma current of 1 MA, a peaked electron temperature profile with about 800 eV at the center is obtained. The total bremsstrahlung power was also evaluated using the electron temperature profile and the absolutely evaluated etendue of each viewing chord. In this evaluation, the bremsstrahlung power is around 10% of ohmic heating power.
为首次等离子体实验，在JT-60SA中设计并安装了一套软X射线（SX）诊断系统。为进行定量测量，对每个观测弦的光学扩展量进行了分析和数值评估。通过检测两个带有不同厚度Be滤光片的探测器阵列之间的轫致辐射发射率来评估电子温度。针对预期的0 - 3 keV电子温度范围，将两个滤光片的厚度优化为7和50μm。通过椭圆阿贝尔反演方案从线积分发射重建SX发射的一维分布。对于等离子体电流为1 MA的等离子体放电，获得了中心处峰值约为800 eV的电子温度分布。还利用电子温度分布和每个观测弦的绝对评估光学扩展量评估了总轫致辐射功率。在此评估中，轫致辐射功率约为欧姆加热功率的10%。
