Development of fast response calorimeter for neutral beam shine-through measurement on CHS

A fast response calorimeter has been developed for the neutral-beam (NB) sh ine-through measurement. This calorimeter has the following advantages. (1) Temporal variation of the heat load onto the calorimeter can be measured. (2) Measurement under the relatively high heat flux environment is possible . (3) The calorimetric measurement under continuous and steady-state heat l oad environment is also possible. The verification of the measurement princ iple was done using an NB-injection system on the compact helical system (C HS) at the National Institute for Fusion Science (NIFS). The measured NB po wer densities are compared to the power densities being evaluated by the CH S-NB profile database. It was experimentally confirmed that the time consta nt of the measurement is about 7 ms. (C) 2001 American Institute of Physics .