On Ion Temperature Profile Measurements in ITER by means of Neutron Spectroscopy
In the next generation of magnetic fusion experiments, such as the International Tokamak Engineering Reactor (ITER), information on ion temperature profiles will be needed for burn optimization and transport studies. The feasibility of obtaining these profiles for the core plasma directly from the width of measured 14 MeV neutron energy spectra is demonstrated for Maxwellian ion distributions. Neutron energy spectra and fluxes are calculated using the Monte-Carlo technique. Reaction kinematics and velocity distribution of the reacting ions are taken into account enabling resulting neutron flux and energy distribution, entering a defined collimator, to be calculated. Energy spectra of neutrons emitted along a line of sight are obtained by adding the contributions from a large number of subvolumes. The relative accuracy is estimated to plus or minus 5%. Features of several spectrometer candidates are briefly described in relation to ITER conditions and measurement requirements. A time of flight neutron spectrometer is outlined. Experiments with a test device confirm the calculated energy resolution and separation of neutron from gamma events. The spectrometer is shown to be applicable to ITER under both ohmically heated and ignited conditions.
Bibliographic Reference: Article: Fusion Technology (1995)
Record Number: 199610397 / Last updated on: 1996-04-15
Original language: en
Available languages: en