An improved method of unfolding neutron TOF spectrum for low ion temperature inertial confinement fusion

Abstract

The fuel ion temperature in inertial confinement fusion can be determined from the neutron energy spectrum. For the implosion experiment with low neutron yield, and thus low signal-to-noise ratio, a new technique to unfold the neutron energy spectrum from the observed neutron time-of-flight signal is presented in this paper. This method uses a low-pass filter to remove noise from the signal with a threshold value determined by power spectrum analysis. This technique has been applied to the analysis of the observed neutron time-of-flight signals in the indirect drive implosion experiment conducted on Shenguang III prototype laser facility, and fuel ion temperatures of about 1.0 keV are obtained.