A correlation study on the TL, OSL and ESR signals in commercial BeO dosimeters yielding intense transfer effects

Highlights: • The correlation on TL, OSL and ESR signals in BeO ceramic were studied. • The decay kinetic and bleaching of the ESR centers were presented. • The transfer effect and TA-OSL signal of BeO signal was investigated. -- Abstract: BeO ceramics have been used for quite a long time as radiation dosimeters besides being used in many other areas. BeO dosimeters can be stimulated both thermally and optically, giving rise to TL and OSL signals. BeO has two main dosimetric peaks, 2 and 3, by ignoring peak 1 that corresponds to a shallow trap, while the OSL curve is composed of two components, termed as C₁ and C₂. Irradiated BeO dosimeters showed ESR spectra at room temperature consisting of three centers I, II and III. These centers were assigned to Al⁺² and O^- centres; two different typical oxygen centre behaviours were monitored, one showing anisotropic and one isotropic properties. The present study attempted to perform correlation between the TL peaks 2 and 3, the CW-OSL components C₁ and C₂ and ESR centers I, II and III. The bleaching and decay features of the ESR centers are presented for the first time in the literature. The OSL component C₁ is correlated with the TL peak 2; both luminescence entities are associated with the ESR center I, attributed to the Al⁺² center. Finally, thermal stability of center II suggests that it can be also tentatively correlated to both TL peak 2 and OSL component C₁. Moreover, the present study provides strong experimental arguments towards a correlation between TL peak 3, CW-OSL component C₂ and ESR center III, namely oxygen ion (isotropic). Intense transfer was monitored either (a) from deeper traps to both traps responsible for TL peaks 2 and 3, as well as (b) from the trap of TL peak 3 to that of TL peak 2. Nevertheless, reconstruction as well as indirect TA-OSL signal monitoring indicates that the transfer is more intense to the trap corresponding to TL trap 3. For this reason, even after depleting both TL peaks, intense OSL curves were still measured.