title: Evaluation of doses in radiotherapy using solid-state composites based on natural colourless topaz.
abstract: The thermoluminescent properties of composites containing powdered topaz embedded in Teflon or glass were studied and compared with the corresponding properties of the well known TLD-100 commercial dosimeters. Relative sensitivity, TL fading, reproducibility of the sample preparation process, and possibility of re-utilisation of the dosimeters were investigated. Measurements of absorbed doses in simulated radiotherapy treatments were also taken. The irradiations were performed using gamma rays from a 60Co source in the dose range from 1cGy to 2Gy. The dosimeters were installed in badges and attached inside acrylic plates of various thicknesses in the radiation fields. The dose profiles obtained with this procedure are very similar to the ones obtained with equivalent tissues. It is concluded that these composites of natural colourless topaz crystals can be efficiently used as TL dosimeters.
authors.affiliation: Depto de Educacz.Trkhk;ão, Universidade Federal de Sergipe, São Cristóvão, SE, 49100-000, Brazil. dnsouza@fisica.ufs.br
authors.forename: Divanizia N
authors.initials: DN
authors.lastname: Souza
authors.forename: Reges A
authors.initials: RA
authors.lastname: Meira
authors.forename: José F
authors.initials: JF
authors.lastname: Lima
authors.forename: Mário Ernesto G
authors.initials: ME
authors.lastname: Valerio
authors.forename: Linda V E
authors.initials: LV
authors.lastname: Caldas
mesh_terms: D000538:Aluminum Silicates / Q000737:chemistry / Q000528:radiation effects*; D003116:Color; D004307:Dose-Response Relationship, Radiation; D005069:Evaluation Studies as Topic; D005720:Gamma Rays; D005898:Glass / Q000737:chemistry; D006358:Hot Temperature; D008163:Luminescent Measurements; D011138:Polytetrafluoroethylene / Q000737:chemistry; D011854:Radiochemistry; D011878:Radiotherapy / Q000379:methods*; D011879:Radiotherapy Dosage; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013819:Thermoluminescent Dosimetry / Q000379:methods* / Q000706:statistics & numerical data
chemical_list: D000538:Aluminum Silicates; D011138:Polytetrafluoroethylene