The Thermoluminescent Properties of G-200 Feldspar in a Pressed Potassium Bromide (KBr) Matrix
T.A. Lebeis; W.G. West; M.L. Rodrigues; A.F. Kalchik; and K.J. Kearfott (University of Michigan)
Feldspars are silicate minerals that are currently used for optically stimulated luminescence dating of geological formations. Upon irradiation, some electrons in the feldspar become de-localized (i.e. are excited into the conduction band) and may be trapped at impurity centers. Feldspar will emit light when stimulated by heat or an appropriate wavelength of light as a result of it's trapped electrons returning to their original energy state. Light is emitted in proportion to the original radiation dose. The material could thus serve as a dosimeter. Feldspar samples were formed by mixing G-200 feldspar powder (a specific blend of feldspar) with potassium bromide and then pressing into a wafer using a pneumatic press. The resulting disks were then exposed to varying levels of Cs-137 gamma radiation. The glow properties of the feldspars were studied using a commercial thermoluminescent dosimetry reader. Pure potassium bromide was also studied in this manner, as this could serve as a binding matrix for other thermoluminescent materials.