TIME AND SPACE RESOLVED ENERGY FLUX MEASUREMENTS IN THE DIVERTOR OF THE ASDEX TOKAMAK BY COMPUTERIZED INFRARED THERMOGRAPHY
A new, fully computerized and automatic thermographic system has been developed with central components AGA THV 780 infrared camera and PDP-11/34 computer. The temperature profile of a single line can be recorded at repetition rate of 2500 Hz, spatial resolution of 128 data samples per line and signal resolution equivalent to a blackbody temperature of 0.2 degrees C. 25 pictures with 64 lines each are recorded per second. The power fluxes absorbed by the ASDEX neutralizer plates are computed from the measured surface temperature evolution: a combined analytical numerical method of solving the one-dimensional heat diffusion equation for a solid of finite thickness bounded by two parallel planes was developed. In high density (n-e=8 x 10**13cm**-3) neutral beam heated (L mode) divertor discharges, the power deposition on the neutralizer plates is reduced to about 10-15%, and 30% to 40% of the power is missing in the global balance; explanations are given/attempted. The power flow inside the divertor chambers is restricted to an approximately 1 cm thick plasma scrape-off layer. During ELM activity free H phases the energy flow into the divertor is blocked, during H phases with ELM activity the energy is expelled in very short intense pulses. Sawtooth events can transport significant amounts of energy from plasma core to peripheral zones and scrape-off layer.
Bibliographic Reference: WRITE TO MAX-PLANCK-INSTITUT FUER PLASMAPHYSIK, 8046 GARCHING BEI MUENCHEN (GERMANY) MENTIONING REPORT IPP III/97, 1984
Record Number: 1989123101500 / Last updated on: 1987-01-01
Available languages: en