Application of cavity theory to the response of various TLDs to gammas degraded in water

Abstract

Several types of thermoluminescent dosimeters (LiF:Mg, Ti, Al2O3:Mg,Y and CaF2:Mn) were irradiated at different depths in a water phantom placed at a distance of 2.5 m from a panoramic 60Co source. Detectors were encapsulated in Plexiglas holders with a wall thickness of 0.5 cm. Reference dosimetry was carried out using a Fricke dosimeter and an ionization chamber. The experimental data were compared with the predictions of the general cavity theory for gamma ray spectra at different depths of water. The suitability of parameters of the cavity theory proposed by different authors was evaluated in the analysis of the experimental results. The results show that there is no need for any modification to the original and simple Burlin expression which gives very good agreement with the experimental values.

The Effect of the Size of Radiotherapy Photon Beams on the Absorbed Dose to an Al2O3Dosimeter

“…This is coincident with our results. Using the cavity theory of Horowitz-Dubi, MILIANIC et al [4] showed that in 60 Co γ beams the absorbed dose ratio factor of the Al 2 O 3 dosimeter was 1.147 (a reciprocal of the original data D d /D m = 0.872), which is also in good agreement with our results.…”

Characterization of the nanoDot OSLD dosimeter in CT

“…k Q can be determined empirically or by using cavity theory, 24 where the dose to the cavity is due to both electrons crossing the cavity and secondary electrons created within the cavity. 30,31 When using the cavity theory approach, the calculated dose to the dosimeter (D Al 2 O 3 :C ) is the dosimeter signal, and thus, the correction factor can be defined as follows [Eq. (6)]:…”

Characterisation of energy response of Al2O3:C optically stimulated luminescent dosemeters (OSLDs) using cavity theory

“…Burlin cavity theory consists of two components to account for both the dose that arises from the secondary electrons crossing the cavity and the dose from the secondary electrons that are created inside the cavity. Although many modifications of Burlin theory have been proposed, Miljanic and Ranogajec-Komor (8) found that the most general expression of Burlin cavity theory is in good agreement with experimental results; therefore, the general Burlin cavity theory shown in Equation (1) (8,12) was used to calculate the dose to the OSLD:…”

“…In principle, correction factors can also be calculated using cavity theory, which has been used, in previous studies, to determine the energy dependence of other solid-state detectors (6 -11) . Burlin cavity theory is most appropriate for 'medium-sized' cavities, where the total dose is due to contributions from both photon and electron interactions inside the cavity (8,12) . Cavities of varying physical size can thereby be well approximated using this theory.…”