TUNNELING RADIATIVE RECOMBINATION IN K-FELDSPAR SANIDINE

A study has been made of the afterglow from three sanidine samples following beta irradiation. The temperature was lowered to 77 K, then raised to 750 K and the emission spectra were measured from ultraviolet (u.v.) to 890 nm. An intense emission is observed at liquid nitrogen temperature, entirely in the red and infrared (i.r.) part of the spectrum, and is attributed to tunnelling radiative recombination. It is intensified by an unusual effect akin to thermal quenching. As the temperature is raised to 750 K, the TL glow peaks display an increasing part of their emission in the better known ''blue'' band as well as in the ''red'' and i.r. band first observed. It is concluded that fading should accompany the observed tunnelling recombination.