Improvements in the Use of Ceramic BeO for TLD

Abstract

Several types of commercially available ceramic Be0 are evaluated for thermoluminescence and combined thermolurninescence-exoelectron dosimetry (TLD-TSEE) . The ceramic Thermalox 995 is superior in nearly all respects. Physical and chemical treatments which enhance or reduce sensitivity and stability of TSEE exert often similar influences on the TL. A thin surface region, which is rich in impurities, suppresses spurious emissions of both light and electrons and allows combined TL and TSEE measurements to be made on the same B e 0 disk. The luminescence is a maximum at 260 nm requiring a reader with a u.v.-sensitive photomultiplier tube. The characteristics important for TLD are as follows: a lower exposure limit of 1 mR with supralinearity starting at 10 R; only 10 % fading after 3 months at 3OoC and 90 % relative humidity, but rapid bleaching in laboratory fluorescent lighting of 50 % in 30 min; and an energy dependence of response similar to that of LiF TLD.

Lu2O3-based storage phosphors. An (in)harmonious family

“…Other important dosimetric materials are Al2O3:C, CaSO4:Dy, MgB4O7:Dy, MgB4O7:Gd,Li, BeO etc. [41,44,45,46,47,48,49]. However, those based on LiF, and MgB4O7 having the density of ~2.65 g/cm 3 and 2.53 g/cm 3 , respectively are the most tissue equivalent, and therefore they are so commonly used in dosimetry.…”

New aspects of a BeO-based optically stimulated luminescence dosimeter

“…The optical sensitivity of BeO is well known since its * Corresponding author. application as TL-material (Tochilin et al, 1969;Crase and Gammage, 1975). Regarding OSL, it was firstly investigated by Bulur and Göksu (1998).…”

Optical Storage Phosphors and Materials for Ionizing Radiation

“…Compared with other commercial thermoluminescence dosimetric systems, the main disadvantage of the BeObased materials is the rapid light-stimulated thermoluminescence fading. Under laboratory fluorescent light, rapid fading of 50 % in 30 min for the thermoluminescence peak at 167 ºC has been reported in several types of commercial BeO ceramic dosimeters (Crase & Gammage, 1975). Based on the characteristic light-sensitive thermoluminescence of BeO, Albrecht and Mandeville (Albrecht & Mandeville, 1956) first investigated optically stimulated luminescence of the X-ray irradiated BeO by using visible photons.…”