The response of a solid state detector, such as
- Thermoluminescence detectors (TLDs)
- Detectors based on optically stimulated luminescence (OSDs)
- Radiographic / radiochromic film
- Si detectors
can be very different when exposed to a particle beam instead of gamma or x-ray radiation. The reason is the high ioziation density in tracks of particle with high LET compared to the more homogenenous energy deposition of photon and x rays ('sea of electrons') or even high energy (='low LET') particles. Rather than in absolute terms of detector response this behaviour is more often described by the means of 'relative detector efficiancy'. Here, the response of the detector in a radiation field Q at dose D is compared to the response in a low LET field such as Co-60:
N.B. that this definition is slightly different than the one for RBE in radiobiology.
Amorphous track models are intended to predict the differences in (relative) response.