Timing properties of transmission avalanche counters at moderate specific ionization

Time resolution measurement of avalanche counters using digital signal processing technique

“…This FWHM is around 86 ps smaller than that obtained with moving average filter and 230 ps smaller than that of without filtration. The time resolution obtained with smoothing spline filter matches the best literature results using analog electronics which have been reported w400 ps for PPACs with 3 mm gap and in tests with a-particles of 241 Am (Mazur and Ribrag, 1983;Sernicki, 1986;Swan et al, 1994). We also measured the intrinsic time resolution of the PPACs using the standard analog electronics including timing filter amplifiers (ORTEC 474), constantfraction-discriminators (CANBERRA 2126), a time-to-amplitude converter (ORTEC 566) and a computer-based MCA.…”

1 Gas Filled Detectors

“…Under these low pressure conditions, a voltage of a few hundred volts applied between the plates, typically 300 V/cm-mbar, is sufficient to ensure the proportional regime. Best timing performance may not necessarily correspond to the fastest output rise time, since at very low gas pressure, pulse fluctuations can become important [91]. It seems that pure hydrocarbons are best suited for these detectors, the highest gains being reached with isobutane [90], Multiplication factors of a few thousands are obtained.…”

“…Electrons released gain enough energy to induce immediate secondary ionization in the homogeneous electric field, and a Townsend avalanche is formed [15]. Time resolutions better than 200 ps (fwhm) have been obtained with such detectors even in large dimensions [92], Of course a delay of 40 to 50 ps/cm from the propagation time of signals along the electrodes has to be taken into account [91]. 100% detection efficiency can be achieved in a wide domain of energy losses.…”