OSL in Al2O3

New Design

For my new set-up, I have used a photomultiplier tube (PMT). The PMT also makes use of the photoelectric effect, except it is far more sensitive than a photodetector. The set-up is a box with the blue filter on top. The crystal sits on the filter, and the laser shines on the crystal.

In order to make full-use of the sensitivity of the PMT, the apparatus had to be shielded. Thus far, the PMT has shown pretty conclusively that F+-centers have been created from x-ray irradiation. The irradiated crystal consistently at least doubles the intensity of the light striking the PMT. Evidence also suggests that the "unirradiated" crystal also has F+-centers but more sparsely than the other.


This shows the sensitivity of the PMT. It seems that the unirradiated crystal has been exposed to some amount of irradiation from other sources.

These show the bleaching of F+ centers. (They are the same data plotted with different scales.)


I plan to continue by testing the irradiation dose-rate with the measured intensity. I also intend to try to find a more stable laser as the laser-pointer is not designed for such extended use.