The simultaneous measurement of luminescence and photocurrent of an irradiated K-feldspar excited with 1.45 or 2.41Â eV photons

Simultaneous photocurrent and luminescence measurements were carried out on a K-feldspar crystal. There was a small photocurrent with 2.41 eV (515 nm) photon excitation. The photocurrent was reduced to near background levels by preheating the sample for 16 h at 120 ∘C, even though there was still a substantial luminescence intensity. There was no measurable photocurrent with 1.45 eV (850 nm) photon excitation. The data are tentatively explained using a model in which electrons are optically excited from different trap types to different parts of the conduction band. In this model, the depth of the principal trap used for dating is ⩾ 2.41 eV below the conduction band.