A Prototype Double Bragg Detector for Fission Yield Measurements

Abstract

This work details the commissioning and further development of a double gridded Bragg detector (DGBD), for the purpose of investigating the energies, masses and angular distributions fission fragments. The process of charge collection in ionisation chamber is also investigated, as is the efficacy of using the DGBD to perform measurements in fast neutron fluxes. Optimal operating conditions for the DGBD were determined using a ^{252}Cf(sf) source and two different fill gases are compared. Digital signal processing algorithms were developed to perform the necessary correction to the recorded pulse traces and further analysis was performed to correct the mass distributions obtained for the effects of pulse- high-deficit and neutron-evaporation. Investigation into signal generation was performed using a segmented anode; and study of the background rates experienced in fast neutron fluxes was performed using 2.5 MeV and 14.2 MeV neutrons at the LPSC, Grenoble and by Monte Carlo simulation. The DGBD was found to operate to a high standard but that the fission fragment source used in the present study results in energy losses of \sim10\,\% in both detector regions. It was found that Frisch grid inefficiency of

Date of Award	31 Dec 2017
Original language	English
Awarding Institution	The University of Manchester
Supervisor	Alastair Smith (Supervisor) & Robert Mills (Supervisor)