A Backscatter-Suppressed Beta Spectrometer for Neutron Decay Studies
  We describe a beta electron spectrometer for use in an upcoming experiment that will measure the beta-antineutrino correlation coefficient (a-coefficient) in neutron beta decay. Electron energy is measured by a thick plastic scintillator detector. A conical array of plastic scintillator veto detectors is used to suppress events where the electron backscattered. A Monte Carlo simulation of this device in the configuration of the a-coefficient experiment is presented. The design, construction, and testing of a full-scale prototype device is described. We discuss the performance of this spectrometer with respect to its suitability for the experiment. 
F.E. Wietfeldt, C. Trull, R. Anderman, F.B. Bateman, M.S. Dewey, A.   Komives, A.K. Thompson, S. Balashov, Yu. Mostovoy