Deposition Diagnostics for Next-step Devices

Skinner, C.H. ; Roquemore, A.L. ; team, the NSTX ; Bader, A. ; Wampler, W.R.

Princeton University. Plasma Physics Laboratory.

关键词: Dusts;    Quartz;    Time Resolution;    70 Plasma Physics And Fusion Technology;    Mirrors;   

DOI  :  10.2172/828039
RP-ID  :  PPPL-3965
RP-ID  :  AC02-76CH03073
RP-ID  :  828039

美国|英语

来源: UNT Digital Library

【 摘 要 】

The scale-up of deposition in next-step devices such as ITER will pose new diagnostic challenges. Codeposition of hydrogen with carbon needs to be characterized and understood in the initial hydrogen phase in order to mitigate tritium retention and qualify carbon plasma facing components for DT operations. Plasma facing diagnostic mirrors will experience deposition that is expected to rapidly degrade their reflectivity, posing a new challenge to diagnostic design. Some eroded particles will collect as dust on interior surfaces and the quantity of dust will be strictly regulated for safety reasons - however diagnostics of in-vessel dust are lacking. We report results from two diagnostics that relate to these issues. Measurements of deposition on NSTX with 4 Hz time resolution have been made using a quartz microbalance in a configuration that mimics that of a typical diagnostic mirror. Often deposition was observed immediately following the discharge suggesting that diagnostic shutters should be closed as soon as possible after the time period of interest. Material loss was observed following a few discharges. A novel diagnostic to detect surface particles on remote surfaces was commissioned on NSTX.