The conversion of a pulse height analyzer to a time analyzer

A transistorized time unit circuit has been designed to convert a 400-channel amplitude analyser (RIDL model 34-12B) to a 400 channel time analyser. The obtained time analyser has channel widths of 24.4 μs, 48.8 μs, 97.6 μs. Experimental determination of the stability of the obtained time analyser was carried out by measuring statistically distributed pulses at constant rate. The stability of the time analyser for long time operation was found to be not less than 0.14%. The linearity of the time scale calibration was checked by measuring the transmission of neutrons through a polycrystalline powder of nickel. This method was found to give a more precise calibration of the time scale than the method based on using the transmission of the elements with well known resonances. From the experimental values obtained for Bragg's cut-off positions for nickel, the non linearity was calculated and found not to exceed 0.3%