A concern on in-phantom photon energy response of luminescence dosimeters for clinical applications

A recent intercomparison of solid state dosimeters demonstrated [6] that the depth-dependent change in the sensitivity of LiF TLD chips due to the change in the photon energy spectra is one of the reasons for the uncertainty in the measurements of doses. In general, the experimental measurements of photon energy responses by most authors has remained limited to exposures free in air (by holding the dosimeters in appropriate build-up materials) in defined beams of X- and gamma ray energies and using air-Kerma values (free in air).