A TLD-based few-channel spectrometer for mixed photon, electron, and ion fields with high fluence rates

A few-channel spectrometer for mixed photon, electron and ion radiation fields has been developed. It consists of a front layer of an etched-track detector foil for detecting protons and ions, a stack of PMMA with thermoluminescent detectors at different depths for gaining spectral information about electrons, and a stack of metallic filters with increasing cut-off photon energies, interspersed with thermoluminescent detectors for gaining spectral information about photons. From the reading of the TL detectors the spectral fluence of the electrons (400 keV to 9 MeV) and photons (20 keV to 2 MeV) can be determined by an unfolding procedure. The spectrometer can be used in pulsed radiation fields with extremely high momentary values of the fluence rate. Design and calibration of the spectrometer are described.