Supersonic neutral particle beam for tokamak plasma diagnostics

用于托卡马克等离子体诊断的超音速中性粒子束

基本信息

批准号：
07680509
负责人：
ODA Toshiatsu
金额：
$ 1.28万
依托单位：
HIROSHIMA UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1995
资助国家：
日本
起止时间：
1995 至 1996
项目状态：
已结题

项目摘要

The main objective of this research is to develop a supersonic helium atomic beam method for diagnosis in the edge region in magnetic confined fusion plasmas by use of spectroscopic techniques. The outline of the present research results is as follows :1.Numerical study of atomic processes of the supersonic helium atomic beam in the plasma edges : The excitation and ionization processes of the helium atomic beam injected into a middle size tokamak plasma (the JFT-2M tokamak at JAERI) was numerically studied in the plasma edges by using a set of the rate equations for the populations of the excited and ionic states of helium. It was shown that the electron density and temperature could be determined from intensity measurements of two different pairs of He I lines, and also that spatial distribution of the electric field induced in the edges could be measured by using a laser-induced fluorescence technique. 2.Atomic collision process between ionized helium atom and hydrogen molecule in plasmas : A numerical study on the basis of a collisional-radiative model was performed on a charge-exchange process between He^<++> and H_2, which could play an important role in the divertor plasmas. 3.A fast numerical calculation method of the rate equation for the plasmas was developed. 4.A supersonic helium atomic beam source was constructed by using a pulsed nozzle and a set of skimmer in a small size vacuum chamber. Spectroscopic measurements revealed this beam could be applicability to torus plasmas. 5.A helium metastable atomic beam was produced using a ECR plasma source. 6.A laser-induced fluorescence method for measurement of electric field distribution in magnetically confined plasmas was developed taking account of the effect of the magnetic field.

本研究的主要目的是开发一种超音速氦原子束方法，利用光谱技术对磁约束聚变等离子体的边缘区域进行诊断。目前的研究成果概要如下：1.等离子体边缘超音速氦原子束原子过程的数值研究：氦原子束注入中等尺寸托卡马克等离子体（JFT-通过使用一组氦激发态和离子态的速率方程，在等离子体边缘对 JAERI 的 2M 托卡马克装置进行了数值研究。结果表明，电子密度和温度可以通过两对不同 He I 线的强度测量来确定，并且可以通过使用激光诱导荧光技术来测量边缘感应电场的空间分布。 2.等离子体中电离氦原子与氢分子的原子碰撞过程：基于碰撞辐射模型对He^<++>与H_2之间的电荷交换过程进行了数值研究，该过程可以发挥重要作用在偏滤器等离子体中的作用。 3.建立了等离子体速率方程的快速数值计算方法。 4.在小型真空室内采用脉冲喷嘴和一组撇渣器构建了超音速氦原子束源。光谱测量表明该光束可能适用于环面等离子体。 5.使用ECR等离子体源产生氦亚稳态原子束。 6.考虑磁场的影响，开发了一种测量磁约束等离子体电场分布的激光诱导荧光方法。