Fission fragment spectroscopy with large surface barrier detectors

Abstract

Large area ( A = 8.5 cm 2) surface barrier detectors have been tested for consistent time-of-flight and pulse height spectroscopy of fission fragments. Timing was measured with fast and narrow IR laser diode pulses; it yielded a resolution (97±14) ps and an integral width of (228±58) ps fwhm with detectors cooled −20o°C. Mass dependent plasma delay differences were obtained from correlated 252Cf fragment determination and linear momenta from two time-of-flight measurements for different distances. Pulse height spectroscopy performed with the Schmitt calibration constants yielded linear momenta that were 1.2% higher; this discrepancy is removed if the revised calibration cconstants yielded linear momenta that were 1.2% higher; this discrepancy is removed if the revised calibration constants derived with fragments of known energies of Weissenberger et al. are used.