Section 7.1.6.1.2. Linearity of response

The linearity of a counter depends on the counting losses, which are due to the finite dead-time of the counter and its processing circuits. The counting losses are affected by the time modulation, if any, of the source, as, for example, with storage rings (Arndt, 1978).

Counting losses can affect the behaviour of detectors in two different ways. In most analogue detectors and in counters with parallel read-out, each pixel behaves as an independent detector and the counting loss at any point depends only on the local counting rate. In other devices, such as multiwire proportional chambers with delay-line read-out (see Subsection 7.1.6.2), the whole detector becomes dead after an event anywhere in the detector and what matters is the global counting rate.

Fortunately, the fractional counting loss is the same for all parts of the pattern so that the relative intensities in a stationary pattern are not affected.