Digital signal processing application to 252Cf(sf) reaction products spectroscopy
The emission of prompt fission neutrons in spontaneous fission of 252Cf was studied by the application of digital data processing for the first time. The study was aimed at comparing the obtained results with those from the pioneering work of Budtz-Jorgensen and Knitter. By using a twin Frisch grid ionization chamber for fission fragment detection and a neutron scintillator (NE213) for the detection of neutrons, a total of about 107 neutron coincidences were registered. The fission-fragment kinetic energies were measured using a fast (80 MHz) waveform digitizer that provided 10-bit amplitude resolution. Standard analog NIM modules were used for neutron time-of-flight and pulse shape measurements. A time-to-digital converter (TDC) with 1-ns resolution and a pair of gated charge-to-digital converters with 12-bit amplitude resolution were also used. The fission fragment signals were analyzed by means of digital signal processing algorithms. Data on prompt fission neutron energies were obtained by using a time-of-flight (TOF) spectrum unfolding procedure applicable to list-mode data.