Dosimetry of heavy charged particles with thermoluminescence detectors--models and applications.

Lithium fluoride thermoluminescent (TL) detectors, with Li-7 isotope and various activators (MTS-7 LiF:Mg,Ti, MTT-7 LiF:Mg,Ti with enhanced Ti concentration and MCP-7 LiF:Mg,Cu,P) were used for dosimetry of heavy charged particles, within the ICHIBAN experiment. The microdosimetric model has been applied to calculate detection efficiency, eta, relative to gamma-ray dose, of these detectors after proton and heavy charged particle (HCP) irradiation for ion charges ranging from Z = 1 to Z = 6 and in the energy range from 0.3 to 20 MeV amu(-1). The calculated ratio eta(MCP-7)/eta(MTS-7) lies in the range between 0.2 and 1.0 for protons and between 0.2 and 0.4 for HCP with Z > 1. The calculated value of eta(MTT-7)/eta(MTS-7) for protons was found range between 1.0 and 1.45 and, for Z > 1, between 1.3 and 2. These relationships can be applied to derive information about the 'effective LET' in an unknown HCP field and to correct the TLD readings for dose evaluation.