Signal Shaping and Tail Cancellation for Gas Proportional Detectors at High Counting Rates

A low noise, wide bandwidth preamplifier and signal processing filter were developed for high counting rate proportional counters. The filter consists of an eight pole Gaussian integrator with symmetrical weighting function and continuously variable shaping time, ?s, of 8 ns to 50 ns (FWHM) preceded by a second order pole/zero circuit which cancels the long (1/t) tails of the chamber signals. The preamplifier is an optimized common base input design with 2 nsec rise time and an equivalent noise input charge of < 2000 rms electrons, when connected to a chamber with 10 pF capacitance and at a filtering time, ?s, of 10 ns.

[1]  V. Radeka Signal, Noise and Resolution in Position-Sensitive Detectors , 1974 .

[2]  A. H. Walenta,et al.  Relativistic Rise Measurement by Cluster Counting Method in Time Expansion Chamber , 1980, IEEE Transactions on Nuclear Science.

[3]  A. H. Walenta,et al.  The Time Expansion Chamber and Single Ionization Cluster Measurement , 1979, IEEE Transactions on Nuclear Science.

[4]  V. Polychronakos,et al.  Relativistic Rise Measurements with Very Fine Sampling Intervals , 1981, IEEE Transactions on Nuclear Science.

[5]  J. L. Alberi,et al.  Position Sensing by Charge Division , 1975, IEEE Transactions on Nuclear Science.