On-Line Hear Deposition Rate Measurements with a Quasi-Adiabatic Graphite Calorimeter in a Fusion Environment and Comparison with Calculations

Abstract

Heat deposition measurements have been carried out by a highly sensitive quasi-adiabatic graphite calorimeter by irradiating with a mixed field of neutron and gamma radiations from a 14 MeV Haefely neutron generator. The core of the calorimeter measures 16 mm in dia and 3 mm in height. It is surrounded by a thin jacket and finally a double shield for insulating the sensitive core region from the ambient temperature fluctuations. All the regions are separated from each other by regions of dynamic vacuum. The reproducibility of the measurements have been found ta be better than 1% for a dose rate more than 60 cGy/min. The heating rates vary linearily with the source strength. These measurements have been analysed by a Monte-Carlo neutron and photon transport code MCNP, using bmccs2, photxs2 and 12 cross-section libraries. The influence of wall returned neutrons and gamma is found to be negligible. The C/E for the heat deposition rates is found to be 1.05.