Neutral Gas Diagnostic for ITER
A crucial point for ITER will be to keep the power load in the divertor at an acceptable level. Key roles in recent concepts play strong radiation from the plasma edge, high neutral gas density and a low plasma edge, high neutral gas density and a low plasma temperature in the divertor region ie ITER has to be operated close to the density limit. Under these conditions a reliable and fast neutral gas diagnostic is mandatory to achieve high performance. For total pressure measurements ASDEX gauges are proposed to be installed at about 100 different positions in the divertor. These gauges can cope with the typical conditions inside fusion experiments, if they are operated by a special electronic control unit. Long term operation at high temperature and nuclear radiation levels can degrade the insulators. The gauges work, however, still satisfactorily with a resistance between the electrodes as low as 100 kohms, nevertheless some neutron shielding would be beneficial. Besides the total pressure measurement information on the gas composition in the divertor, especially on the He content, is desirable for the exhaust of the He ash and other impurities. Possible candidates for this task are discussed (Quadrupol RGA's, Penning and ASDEX gauge based spectroscopic detection systems for He and other gases).
Bibliographic Reference: Article: Diagnostics for Experimental Thermonuclear Fusion Reactors (1996) pp. 571-579
Record Number: 199610844 / Last updated on: 1996-08-16
Original language: en
Available languages: en