# Dimensions of radiation detector and range of secondary particles

1. ### mitch_1211

99
Hi All,

Just reading up on methods of neutron detection and something struck me. Generally these types of detectors are manufactured small enough so the the ranges of the charged particles (usually tritium and alpha) are smaller than the dimensions (so around 100microns or so). This means that the detector is smaller than the range of secondary charged particles created from gamma interactions (typically millimetre range), which is desirable to produce a neutron only spectrum.

I wondered what happened when an electron is generated from a gamma interaction and it goes along its track and reaches the edge of the detector (which is much smaller than its mean free path). Does it simply escape as beta radiation?

The detector in this case is a glass fibre scintillator with Li6 dopant.

Mitch