Time Resolved Deposition Measurements in NSTX.

Skinner, C. H. ; Kugel, H. ; Roquemore, A. L. ; Hogan, J.

Technical Information Center Oak Ridge Tennessee

关键词: Tokamak devices;    Deposition;    Plasma diagnostics;    Carbon;    Configuration;   

RP-ID  :  DE2004828594

学科分类：工程和技术（综合）

美国|英语

来源: National Technical Reports Library

【 摘 要 】

Time-resolved measurements of deposition in current tokamaks are crucial to gain a predictive understanding of deposition with a view to mitigating tritium retention and deposition on diagnostic mirrors expected in next-step devices. Two quartz crystal microbalances have been installed on NSTX at a location 0.77m outside the last closed flux surface. This configuration mimics a typical diagnostic window or mirror. The deposits were analyzed ex-situ and found to be dominantly carbon, oxygen, and deuterium. A rear facing quartz crystal recorded deposition of lower sticking probability molecules at 10% of the rate of the front facing one. Time resolved measurements over a 4-week period with 497 discharges, recorded 29.2 (micro)g/cm(sup 2) of deposition, however surprisingly, 15.9 (micro)g/cm(sup 2) of material loss occurred at 7 discharges.