TIME-OF-FLIGHT SPECTROMETER FOR 2,45 MEV FUSION NEUTRONS
This report describes the properties of a neutron spectrometer for the use of DD fusion neutron measurement at JET. The instrument is designed to measure the plasma ion temperature T-i above 4 keV. The hot plasma affects the kinetic energy of the 2.45 MeV neutrons and broadens their energy distribution (Doppler effect). In the spectrometer this line broadening can be measured. Especially, assuming a Maxwellian plasma ion velocity distribution - characterized by the ion temperature T-i - the broadening of a Gaussian neutron energy peak DELTA-E is given by the simple relationship: DELTA-E = 82.5 square root of T-i (T-i, DELTA-E in keV) The design under consideration is based on experimental investigation and on theoretical evaluation. The principle of measurement is discussed (energy distribution of the DD fusion neutrons around the mean value of 2.45 MeV, using time-of-flight (TOF) technique), followed by energy resolution (which can be evaluated for a given plasma temperature by using the relationship between line broadening DELTA-E and plasma temperature T-i), count rate, instrumentation, data acquisition, calibration system and vertical inspection.
Bibliographic Reference: WORKSHOP ON DIAGNOSTICS FOR FUSION REACTOR CONDITIONS, VARENNA, COMO (ITALY), SEPT. 6-17, 1982, PP. 53-64 351 P., 1983, ISBN 0-08-031161-X WRITE TO PERGAMON PRESS LTD., HEADINGTON HILL HALL, OXFORD OX3 OBW (ENGLAND), PRICE: UKL 47, (EUR 8351 EN).
Record Number: 1989123105900 / Last updated on: 1987-01-01
Available languages: en