Measurement of Radiation Dosage

THE IN VIVO MEASUREMENT of x and gamma radiation within human and biological systems is severely limited by the size and accuracy of the detecting system. In vivo dosimeters must be easily implanted and removed and be capable of reinsertion into the same body areas. There are, at the present time, several types of miniature solid state dosimeters that have indicated promise of use as in vivo dosimeters. The two systems considered are radiophotoluminescence ( RPL ) and thermoluminescence (TL). Each of the systems will be discussed separately.

Radiophotoluminescent Glass

The glass acts as a matrix or host which contains a homogeneously distributed fluorescent activator, silver metaphosphate. Upon exposure to x or gamma radiation, the silver metaphosphate is dissociated and some of the ionic silver is reduced to metallic silver of valence zero. Ionizing radiation has, once these reactions are completed, excited the glass so that upon proper stimulation, visible light will