The development of gas scintillation counters for high count rate x-ray detection

Abstract

This Thesis describes a study of a new type of detector, the gas scintillation counter. The counter is a development of the multiwire proportional chamber and the drift chamber with superior energy resolution and count rate capability. A study of multiwire proportional chambers with a delay-line readout technique, as well as a conventional readout technique, is described. The limitations of this type of detector for high rate experiments are studied and discussed. Measurements and a theoretical study of electron drift velocities in different argon-nitrogen mixtures are presented. The study of the equipotential contours of the electric field inside multiwire proportional chambers and drift chambers, revealed the effect of the chamber dimensions and the applied drift and anode voltages on the field, and consequently on the performance of the chambers. This made it possible to select the most appropriate dimensions and applied voltages. The investigation of the general properties and capabilities of this counter with the detailed study of each parameter helped the choice of suitable parameters for high count rate experiments. Further development work on the detector is proposed and the applications of gas scintillation counters are discussed with particular reference to the new results and characteristics obtainable from this counter.