Development of Diagnostic System for Electric Field Distribution in Plasmas

等离子体电场分布诊断系统的研制

基本信息

批准号：
02558002
负责人：
ODA Toshiatsu
金额：
$ 7.3万
依托单位：
Hiroshima University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Developmental Scientific Research (B)
财政年份：
1990
资助国家：
日本
起止时间：
1990 至 1991
项目状态：
已结题

项目摘要

We have developed a new diagnostic system to measure spectroscopically the spatial distribution of electric fields in plasmas such as various kinds of discharge ones and also the fusion plasmas.1. First of all, we have improved theoretical calculations concerning the measurements. For the hydrogen atom in the plasmas, intensity ratio of- the forbidden transition 3P_<1/2>-2P_<3/2> and the allowed one 3P_<1/2>-2S_<1/2> was numerically calculated as a function of the electric field strength according to the Stark effect. The results shows that the ratio increases to about 0.5 for the field strength of as low as 50V/cm. For the helium atom, the forbidden transition probability 2^1S-3, 4^1D were calculated as functions of the field strength for various values of the exciting dye-laser power as well as the corresponding quadrupole transition probability which is independent of the electric field. Then the intensity ratio of both induced-fluorescences associated with the transitions gives us the electric field strength without any intensity calibration.2. The present diagnostic system consists of mainly a YAG laser-pumped dye-laser for exciting the atoms, a spectroscopic system including optics for spatial measurement, and a data-processing system. Computer programs for control of the devices and for the data processing were developed.3. Measurements of electric field distribution in a cathode dark-space in a hollow cathode discharge plasma were demonstrated. The negative glow potential obtained from the measured field distributions were in good agreement with probe measurements.4. A similar but complicated diagnostic system has been also developed for fusion plasmas, by using a helium neutral beam probe.5. As a future plan, measurement of polarization of the fluorescences will be performed by using the present diagnostics system. This measurement will give us more detailed informations about weak electric fields.

我们开发了一种新的诊断系统，用于光谱测量等离子体（例如各种放电等离子体和聚变等离子体）中电场的空间分布。1．首先，我们改进了有关测量的理论计算。对于等离子体中的氢原子，禁止跃迁 3P_<1/2>-2P_<3/2> 和允许跃迁 3P_<1/2>-2S_<1/2> 的强度比通过数值计算为根据斯塔克效应，电场强度的函数。结果表明，当场强低至 50V/cm 时，该比率增加至约 0.5。对于氦原子，禁戒跃迁概率 2^1S-3、4^1D 被计算为不同激发染料激光功率值的场强函数，以及相应的与电无关的四极跃迁概率。场地。然后，与跃迁相关的两种诱导荧光的强度比为我们提供了无需任何强度校准的电场强度。2．目前的诊断系统主要由用于激发原子的YAG激光泵浦染料激光器、包括用于空间测量的光学器件的光谱系统以及数据处理系统组成。开发了用于控制设备和数据处理的计算机程序。3．演示了空心阴极放电等离子体中阴极暗空间中电场分布的测量。场分布测量得到的负辉光电位与探针测量结果吻合较好。 4．通过使用氦中性束探针，还开发了一种类似但复杂的聚变等离子体诊断系统。5。作为未来的计划，将使用现有的诊断系统来测量荧光的偏振。这种测量将为我们提供有关弱电场的更详细信息。