First Real-Time Detection of Surface Dust in a Tokamak

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

Princeton University. Plasma Physics Laboratory.

关键词: Dusts;    Electrical Faults;    Electrostatics;    70 Plasma Physics And Fusion Technology;    Detection;   

DOI  :  10.2172/981709
RP-ID  :  PPPL-4517
RP-ID  :  DE-ACO2-09CH11466
RP-ID  :  981709

美国|英语

来源: UNT Digital Library

【 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.