NEUTRON SPECTROMETRY IN COMPACT IGNITION EXPERIMENTS

The role of neutron spectrometry is discussed as a diagnostics of plasmas of compact ignition experiments. The situation with regard to instrumentation (including diagnostic capabilities and limitations) is reviewed on the basis of existing experience and new solutions are proposed as required by compact-plasma observations. Especially, the question of time resolution is addressed and a dedicated spectrometer system is devised to make use of the high neutron fluxes expected for the nuclear-burn phase of compact plasmas. It is shown that a system of three neutron spectrometers can provide adequate data on ion temperature of D and DT plasmas over a range of plasma conditions of interest and with the required accuracy. The diagnostic output from this neutron spectrometer system is presented especially with regard to flash ignition studies.