Abstract The polarization properties of the light emitted by the thermoluminescent phosphor TLD-100 (Harshaw Chemical Co.), in crystalline form, is investigated for three different thermal and radiation histories (virgin, sensitized, and desensitized). The results of the investigation show no significant evidence of any type of polarization phenomena present for any of the conditions observed. This fact suggests that the luminescent centers responsible for the TL photons are probably anisotropic...