title: Angular dependence of the TL reading of thin alpha-Al2O3:C dosemeters exposed to different beta spectra.
abstract: The angular dependence of the thermoluminescent (TL) signal of thin alpha-Al2O3:C dosemeters was investigated for a series of beta-emitting radionuclides commonly employed in nuclear medicine and characterised by different mean energies (99Tc, 177Lu, 90Sr/90Y and 90Y). Irradiations were performed in a controlled geometry, using a properly designed irradiator intended to realistically reproduce the situation of exposure of hospital personnel to beta-emitting pharmaceuticals. Under the conditions of extended source and short source to detector distance, the TL signal of thin alpha-Al2O3:C layers per unit irradiation time was observed to be independent on the angle of incidence within acceptable limits, particularly for those radionuclides with maximum energy >500 keV. This property may be easily explained by using simple physical considerations, such as the limited thickness of the dosemeters. The results confirm that these detectors are suitable for beta-ray extremity dose measurements, when the photon contribution is negligible, as in the case considered.
authors.affiliation: Dipartimento di Fisica, Università degli Studi di Milano, Sezione di Fisica Medica, via Celoria 16, I-20133 Milano, Italy.
authors.forename: Pietro
authors.initials: P
authors.lastname: Mancosu
authors.forename: Dario
authors.initials: D
authors.lastname: Ripamonti
authors.forename: Ivan
authors.initials: I
authors.lastname: Veronese
authors.forename: Marie Claire
authors.initials: MC
authors.lastname: Cantone
authors.forename: Augusto
authors.initials: A
authors.lastname: Giussani
authors.forename: Giampiero
authors.initials: G
authors.lastname: Tosi
mesh_terms: D000535:Aluminum; D000537:Aluminum Oxide / Q000737:chemistry; D001610:Beta Particles; D009010:Monte Carlo Method; D017785:Photons; D011829:Radiation Dosage; D011868:Radioisotopes / Q000737:chemistry; D011874:Radiometry / Q000295:instrumentation; D013819:Thermoluminescent Dosimetry / Q000295:instrumentation* / Q000379:methods*; D013997:Time Factors
chemical_list: D011868:Radioisotopes; D000535:Aluminum; D000537:Aluminum Oxide