variety of nuclear radiation detectors such as the type of phoswich scintillation detector used in the harshaw tasc 12 a6 system or a proton recoil neutron detector such as the ludlum 270 series proportional counter preferred adc 16 is a so called 34 flash 34 converter operable for rapid digital conversion of the input analog pulse from detector 12 such as types ad9005 12 bit 10 mhz cav1220 12 bit 20 mhz or 9020 10 bit 60 mhz available from analog devices preferred interface 20 uses a digitally adjustable threshold trigger operable for forwarding data when exceeding a predetermined threshold to a conventional fifo shift register such as type idt 72225 18 bit 50 mhz 1 k bytes or ti sn74act 7801 20 18 bit 50 mhz 1 k bytes dsp 20 is preferably type tms320c40 32 bit 25 mhz 275 mflops available from texas instruments or dsp96002 32 bit 27 mhz 40 mflops available from motorola preferred pc 22 is a 486 based 50 mhz eisa personal computer having sufficient memory capacity for storing pulse shape data and spectrum data for the particular application of apparatus 10 the memory of pc 22 includes sets of pulse shape data stored therein with each set being characteristic of a type of radiation specifically each pulse shape data set includes a set of data points representing the shape of a curve wherein that shape is characteristic of the shape of a pulse produced by detector 12 in response to reception to a particular type of radiation for example fig2 is a graph of pulse amplitudes over time with curve 24 representing the pulse shape caused by reception of a neutron by detector 12 and with curve 26.