光谱法研究等离子体粒子循环和输运

Study of Plasma Particles Recycling and Transport with Spectroscopic Method

介绍了三高斯拟合技术,首先用单高斯选点拟合了Hα线形分布的远翼,由谱线的多谱勒展宽得出等离子体离子温度为170 eV,再对剩余量进行双高斯拟合,从多谱勒频移求出反射和解吸粒子入射速度分别为3.0×104 m/s和1×104 m/s,从谱线辐射强度推出再循环粒子由60%反射粒子和40%解吸粒子组成.在简化模型下讨论了粒子的输运行为,算出了氢原子密度、体发射系数和粒子约束时间的分布,均与实验结果相符.分析了粒子入射速度大小对粒子约束时间的影响,结果表明,正常放电下,HT-6M托卡马克粒子约束时间在4～8 ms反射粒子的速度大小直接决定粒子约束时间的大小和空间分布.

The fitting technique with three Gaussian functions is introduced, The remote wing of Hα line shape is fitted with single Gaussian function at first, the ion temperature of plasma is derived from the Doppler broadening, then the residuals of Hα line shape is fitted with double Gaussian functions. The incident velocity of reflected particles and desorbed particles are 3.0×104 m/s and 1×104 m/s respectively, which are derived from the Doppler shift of Hα line shape. The recycling particles consist of 60% reflected particles and 40% desorbed particles, which are derived from the intensity of Hα line. The profile of hydrogen atom density, the coefficient of emission and the particle confinement time are also obtained from the simplified model of particle transport, agreeing with experimental results. The influence of incident velocity on particle confinement time is analyzed. The result shows that particle confinement time is 4-8 ms with normal discharge in HT-6M Tokamak, the velocity of reflected particles directly dominate the magnitude and the radial profile of particle confinement.