title: Attenuation of diagnostic energy photons by polymer gel dosimeters.
abstract: Post-irradiation changes in the linear attenuation coefficient, mu, of polymer gel dosimeters give rise to a change which can be measured with x-ray computed tomography. Polymer gel dosimeters were manufactured consisting of 3% (by weight) acrylamide and 3% N,N'-methylene-bis-acrylamide comonomers dissolved in aqueous gelatin (5% gelatin by total weight and 89% de-ionized distilled water). Mu was measured in a collimated radiation beam of photons from an 241Am source. Density, rho, of polymer gel dosimeters was measured using volumetric flasks with capillary stoppers. The measured post-irradiation data of mu was plotted against the data of rho for different batches, and linear least squares fits gave r2 values of 0.99605 and 0.99953, with P values of less than 0.001. This confirms that the post-irradiation change in mu is proportional to that of rho. The change in rho implies a change in volume regardless of the evaluation modality of the polymer gel dosimeter.
authors.affiliation: Centre for Medical, Health and Environmental Physics, Queensland University of Technology, GPO Box 2434, Brisbane, Qld, 4000, Australia.
authors.forename: J V
authors.initials: JV
authors.lastname: Trapp
authors.forename: G
authors.initials: G
authors.lastname: Michael
authors.forename: Y
authors.initials: Y
authors.lastname: de Deene
authors.forename: C
authors.initials: C
authors.lastname: Baldock
mesh_terms: D004307:Dose-Response Relationship, Radiation; D005782:Gels; D017785:Photons; D011108:Polymers / Q000737:chemistry*; D011874:Radiometry / Q000379:methods*; D014057:Tomography, X-Ray Computed / Q000379:methods
chemical_list: D005782:Gels; D011108:Polymers