Detailed investigation of a time of flight neutron spectrometer

A neutron spectrometer and telescope based on double elastic interaction in two scintillators was tested on two neutron sources: a solid deuterium titanium target for D(d, n)He3 reaction, and a tritium gas cell for T(p, n)He3. The spectrometer provides a relative resolution of the ion temperature from 20% to 70% at ion temperatures around 1 keV and a flight path length of 2 m. For ion temperatures around 5 keV, the figures are 10% to 20% and for 10 keV, 7% to 10%. The telescope provides spatial resolutions from 0.25 to 0.50 m with flight path lengths from 0.6 to 1.3 m. The width of the energy peak of a neutron source used for calibrating must be known to within a few keV to obtain adequate resolutions.