1.
(a) With reference to the various processes called quenching in gas-filled detectors:
Describe what is meant by quenching in a proportional counter and give an example of a suitable gas that could be used (include an explanation as to why it is desirable to do this). [2 MARKS]
Describe what is meant by quenching in a Geiger-Muller counter and give an example of a suitable gas that could be used (include an explanation as to why it is important to do this). [2 MARKS]
Describe why the transfer of charge between positive ions and neutral molecules is vital in gas quenching inside a Geiger-Muller counter (include an explanation as to why this happens). [2 MARKS]
(b) With reference to a typical cylindrical proportional counter,
(0 Sketch a graph to illustrate the magnitude of the signal produced by the counter as a function of the applied bias voltage assuming the same amount of energy deposited at each voltage and showing the range from zero up to the electrical breakdown of the detector. Carefully annotate your graph to make clear the important features. [2 MARKS]
(ii, State how the size of the signal changes in such a counter when the amount of energy deposited in the counter is changed, for the different voltage regions of your graph.
[3 MARKS]
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