Advances in Electrostatic Dust Detection on Remote Surfaces

Voinier, C. ; Skinner, C. H. ; Roquemore, A. L.

Princeton University. Plasma Physics Laboratory.

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

DOI  :  10.2172/836832
RP-ID  :  PPPL-4049
RP-ID  :  AC02-76CH03073
RP-ID  :  836832

美国|英语

来源: UNT Digital Library

【 摘 要 】

The inventory of dust in next-step magnetic fusion devices will be regulated for safety reasons, however diagnostics to measure in-vessel dust are still in their infancy. Advances in dust particle detection on remote surfaces are reported. Two grids of interlocking circuit traces with spacing in the range 125 mu m to 25 mu m are biased to 30 V. Impinging dust creates a short circuit and the result current pulse is recorded. The detector response was measured with particles scraped from a carbon fiber composite tile and sorted by size category. The finest 25 mu m grid showed a sensitivity more than an order of magnitude higher than the 125 mu m grid. The response to the finest particle categories (5 –30 mu m) was two orders of magnitude higher than the largest (125 –250 mu m) category. Longer duration current pulses were observed from the coarser particles. The results indicate a detection threshold for fine particles below 1 mu g/cm^2.