On the operational characteristics of a gas flow counter

Abstract

In this paper experiments performed with the loop anode gas flow counters are discussed. Experiments have been performed to study the dependence of threshold potential with the variations in (1) source-anode distance and (2) size of the loop. The results obtained with the variations in loop size indicate that there exists an optimum loop size for the minimum of the threshold potential. With a cylindrical chamber optimum radius of the loop obtained is r/3.33 ( r = radius of the counter). A systematic analytical investigation of the occurrence of the optimum loop size gives loop radius to be r/2.67. Another set of experiments is performed to reduce the difference between the results obtained between experimental observations and that of analytical investigation in which spherical counter is used so as to have a closer approach to the assumptions made in the analytical investigations. The results obtained give optimum loop radius to be r/2.80. For the sake of interest loop is replaced by a thin copper disc. The variations in disc size do not indicate occurrence of any optimum disc size so as to give the minimum of the threshold potential.