Comparison of Two Inverse Heat Conduction Models for Heat Flux Measurement in the GAMMA 10/PDX

The new calorimeter recently installed in the GAMMA 10/PDX device of the University of Tsukuba (Ibaraki, Japan) has two thermocouples set near the plasma irradiation surface. This calorimeter quickly responds to heat flux change, and its signal/noise ratio has been improved by an insulation thermoelectric convertor and a metal shield box. In this paper, the heat flux change during a plasma shot was estimated by two analytic models (temperature gradient and pulse decomposition). The obtained heat flux of both methods agreed before plasma termination. Thereafter, the heat flux estimated by the pulse decomposition method failed because the calorimeter signal was disturbed by electromagnetic noise.