First Real-Time Detection of Surface Dust in a Tokamak

Skinner, C. ; Rais, B. ; Roquemore, A. L. ; Kugel, H. W. ; Marsala, R. ; Provost, T.

关键词: DETECTION;    DUSTS;    ELECTRICAL FAULTS;    ELECTROSTATICS;    SENSITIVITY Diagnostics;    Dust Diagnostics;    Plasma Wall Intteraction;   

DOI  :  10.2172/981709
RP-ID  :  PPPL-4517
PID  :  OSTI ID: 981709
Others  :  TRN: US1004493

学科分类：原子、分子光学和等离子物理

美国|英语

来源: SciTech Connect

【 摘 要 】

The first real-time detection of surface dust inside a tokamak was made using an electrostatic dust detector. A fine grid of interlocking circuit traces was installed in the NSTX vessel and biased to 50 v. Impinging dust particles created a temporary short circuit and the resulting current pulse was recorded by counting electronics. The techniques used to increase the detector sensitivity by a factor of x10,000 to match NSTX dust levels while suppressing electrical pickup are presented. The results were validated by comparison to lab measurements, by the null signal from a covered detector that was only sensitive to pickup, and by the dramatic increase in signal when Li particles were introduced for wall conditioning purposes.