He Puff System For Dust Detector Upgrade

[摘要] Local detection of surface dust is needed for the safe operation of next-step magnetic fusion devices such as ITER. An electrostatic dust detector, based on a 5 cm x 5 cm grid of interlocking circuit traces biased to 50 V, has been developed to detect dust on remote surfaces and was successfully tested for the first time on the National Spherical Torus Experiment (NSTX). We report on a helium puff system that clears residual dust from this detector and any incident debris or fibers that might cause a permanent short circuit. The entire surface of the detector was cleared of carbon particles by two consecutive helium puffs delivered by three nozzles of 0.45 mm inside diameter. The optimal configuration was found to be with the nozzles at an angle of 30o with respect to the surface of the detector and a helium backing pressure of 6 bar. __________________________________________________

[发布日期] 2010-10-01

[学科分类] 原子、分子光学和等离子物理

[关键词] CARBON;CONFIGURATION;DETECTION;DUSTS;ELECTRICAL FAULTS;ELECTROSTATICS;FIBERS;HELIUM;NOZZLES Diagnostic s;Dust Diagnostics;Plasma Wall Interaction