Low-background spectrometer for the study of fast neutron-induced (n,alpha) reactions

An a-particle spectrometer based on an ionization chamber with Frisch grid and a waveform digitizer has been developed for studies of fast neutron-ind uced (n,alpha) reactions. The information on the energy of the a-particle a nd its emission angle can be obtained from the amplitude and rise time of t he digitized anode signal. For a situation where both the solid target on t he cathode of the ionization chamber and the working gas are the cc-particl e sources, a new method for the suppression of the neutron-induced backgrou nd is proposed. The background due to gaseous cc-particles was reduced by a factor of 30. (C) 2000 Elsevier Science B.V. All rights reserved.