A particle spectrometer for angular distribution measurements from (n, p) and (n, d) reactions at 22 MeV

Abstract

A particle spectrometer with novel features has been developed for the study of fast neutron-induced particle emission reactions. The principal components of the spectrometer are three flat multiwire proportional counters which act as energy loss detectors and a curved plastic scintillator which provides full energy information and angle determination for each gated event. Energy spectra have been measured with an overall resolution of better than 0.7 MeV (FWHM) for 6 to 22 MeV protons and 8 to 20 MeV deuterons. The spectrometer allows the simultaneous accumulation of data over an angular range of 70° with an angle resolution of about ±5° which is determined by yield and geometrical considerations. The intrinsic angular resolution is about 3° (FWHM) based on position uncertainty in the scintillator strip. Angular distribution measurements for low-yield fast neutron induced reactions are made feasible by effective background suppression and adequate particle identification. The spectrometer can be operated in vacuum but for convenience and simplicity it may operate in air without significantly degrading its capabilities. Results for specific (n, p) and (n, d) reaction studies at E n = 22 MeV using this spectrometer are cited.