ISSN:
1089-7623
Quelle:
AIP Digital Archive
Thema:
Physik
,
Elektrotechnik, Elektronik, Nachrichtentechnik
Notizen:
Power loading on the first wall of a tokamak is an important issue in present research devices and in the design of future devices such as CIT and ITER. In particular, disruptions can deposit large amounts of power in localized areas which can then damage the wall or adversely affect operation. The plasma-facing wall in the Tokamak Fusion Test Reactor (TFTR) is covered in large part by a bumper limiter. This limiter extends the full 360° toroidally inside the vacuum vessel on the small-major-radius side, and ±60° poloidally with respect to the midplane. The TFTR tokamak has the unique feature that the bumper limiter is extensively instrumented with thermocouples. By carefully eliminating noise on the data from these sensors, we can now measure the heat deposition distribution for each discharge. We investigated disruptions due to operation at different operating limits such as (a) high density, (b) low qa, and (c) high beta poloidal (βp). It was found that while there were often common hot spots, different types of disruptions caused different heating patterns and heat loads on the bumper limiter. We also studied the heat distribution created by pulsed discharge cleaning and disruptive discharge cleaning. While originally intended to study disruptions, this new analysis tool has proven valuable for investigating other plasma phenomena such as blooms and detached plasmas, determining the heating effectiveness of various conditioning techniques such as pulsed discharge cleaning and disruptive discharge cleaning, and verifying and checking the alignment of the bumper limiter.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1063/1.1141743
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