title: Ion diffusion modelling of Fricke-agarose dosemeter gels.
abstract: In Fricke-agarose gels, an accurate determination of the spatial dose distribution is hindered by the diffusion of ferric ions. In this work, a model was developed to describe the diffusion process within gel samples of finite length and, thus, permit the reconstruction of the initial spatial distribution of the ferric ions. The temporal evolution of the ion concentration as a function of the initial concentration is derived by solving Fick's second law of diffusion in two dimensions with boundary reflections. The model was applied to magnetic resonance imaging data acquired at high spatial resolution (0.3 mm) and was found to describe accurately the observed diffusion effects.
authors.affiliation: Istituto per le Applicazioni del Calcolo, CNR, viale del Policlinico 137, 00161 Rome, Italy.
authors.forename: F
authors.initials: F
authors.lastname: de Pasquale
authors.forename: P
authors.initials: P
authors.lastname: Barone
authors.forename: G
authors.initials: G
authors.lastname: Sebastiani
authors.forename: F
authors.initials: F
authors.lastname: d'Errico
authors.forename: E
authors.initials: E
authors.lastname: Egger
authors.forename: A M
authors.initials: AM
authors.lastname: Luciani
authors.forename: M
authors.initials: M
authors.lastname: Pacilio
authors.forename: L
authors.initials: L
authors.lastname: Guidoni
authors.forename: V
authors.initials: V
authors.lastname: Viti
mesh_terms: D003198:Computer Simulation; D004058:Diffusion; D004307:Dose-Response Relationship, Radiation; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005296:Ferrous Compounds / Q000737:chemistry* / Q000528:radiation effects*; D005782:Gels / Q000737:chemistry / Q000528:radiation effects; D007474:Ion Exchange; D008422:Materials Testing; D008956:Models, Chemical; D008958:Models, Molecular; D011829:Radiation Dosage; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012685:Sepharose / Q000737:chemistry* / Q000528:radiation effects*; D012996:Solutions / Q000737:chemistry* / Q000528:radiation effects*; D013819:Thermoluminescent Dosimetry / Q000295:instrumentation* / Q000379:methods
chemical_list: D005296:Ferrous Compounds; C075364:Fricke solution; D005782:Gels; D012996:Solutions; D012685:Sepharose