Author/Authors :
Wang، نويسنده , , Zhehui and Morris، نويسنده , , Christopher L. and Gray، نويسنده , , F.E. and Bacon، نويسنده , , J.D. and Brockwell، نويسنده , , M.I. and Chang، نويسنده , , D.Y. and Chung، نويسنده , , K. and Dai، نويسنده , , W.G. and Greene، نويسنده , , S.J. and Hogan، نويسنده , , G.E. and Lisowski، نويسنده , , P.W. and Makela، نويسنده , , M.F. and Mariam، نويسنده , , F.G. and McGaughey، نويسنده , , P.L. and Mendenhall، نويسنده ,
Abstract :
A detector efficiency model based on energy extraction from neutrons is described and used to compare 4He detectors with liquid scintillators (EJ301/NE-213). Detector efficiency can be divided into three regimes: single neutron scattering, multiple neutron scattering, and a transition regime in-between. For an average fission neutron of 2 MeV, the amount of 4He needed would be about 1/4 of the amount of the mass of EJ301/NE-213 in the single-scattering regime. For about 50% neutron energy extraction (1 MeV out of 2 MeV), the two types of detectors (4He in the transition regime, EJ301 still in the single-scattering regime) have comparable mass, but 4He detectors can be much larger depending on the number density. A six-tube 11-bar-pressure 4He detector prototype is built and tested. Individual electrical pulses from the detector are recorded using a 12-bit digitizer. Differences in pulse rise time and amplitudes, due to different energy loss of neutrons and gamma rays, are used for neutron/gamma separation. Several energy spectra are also obtained and analyzed.
Keywords :
scalable , Pulse-shape discrimination , FPGA waveform digitizer , Neutron detection efficiency , Sealed high-pressure 4He drift tubes
