An adaptive digital filter for high-rate, high-resolution gamma spectrometry

By automatically adapting the noise filtering time to individual pulse intervals, the preloaded digital filter (PLDF) combines low- to medium-rate resolutions comparable to those of high-quality Gaussian amplifiers with throughput rates of up to 100 kc/s, and high-rate resolutions superior to those of state-of-the-art gated integrator systems. In contrast to commercially available digital filters, the PLDF in its new implementation performs pulse shortening as well as pole zero cancellation in the analog domain. This not only results in a simpler digital core but also, for the first time, makes possible the use of a low-cost ADC in a spectrometric application. Combined with real-time correction of counting losses according to the loss-free counting method, the PLDF is the core of a novel MCA system for neutron activation analysis of short-lived isomeric transition