Glow-peak stability in 6LiF:Mg,Ti (TLD-600) exposed to a Fe-ion beam.

The stability of glow peaks in 6LiF:Mg,Ti (TLD-600) exposed to a high-energy Fe-ion beam was examined in comparison to 137Cs gamma-ray irradiation under changing annealing conditions. The peak areas induced by the Fe ions were much smaller than those by gamma-rays. The sizes and positions of peaks 3-5 in Fe-ion irradiated samples were hardly changed after post-annealing at 100 degrees C x 30 min, regardless of the pre-annealing conditions (fast quenching or subsequent pre-annealing at 100 degrees C x 2 h). Whereas, the peaks in gamma-ray irradiated samples were notably affected by post-annealing; the peak positions and peak-area sizes changed in different ways depending on the pre-annealing conditions. The effects of post-annealing on peak 6 were identical for Fe ions and gamma-rays. These facts suggest that peaks 3-5 in TLD-600 comprised both stable and unstable luminescent centers, and that the latter part would be easily depleted in highly dense ionization.