engleski

Comparative study of gas amplification and energy resolution in some argon-based mixtures

A mean gas amplification factor M in mixtures of argon with propane and DME at various pressures <50 kPa is studied. The deviations from the linear dependence of gas gain on high voltage in a semi-log plot are compared with those observed earlier in argon-isobutane mixtures. In all three kinds of mixtures, the magnitude M0 of the gas gain where deviations start depends on the partial pressure of the admixture. Energy resolution at 5.9 keV has been measured in pure gases and in argon-based mixtures as a function of the gas gain. The best resolution has been obtained at low gas gains, ~100-200. At these gains better resolution is obtained for mixtures with lower partial pressure of the admixture. At high gas gains energy resolution depends strongly on the admixture partial pressure, and above M0 it degrades much faster due to avalanche chain formation.

gas amplification; proportional counter; gas mixtures; energy resolution

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