Kutna ovisnost radiofotoluminescentnih dozimetara u polju fotonskog zračenja

master's thesis

• Title (english): Angular dependence of radiophotoluminescent dosimeters in photon fields
• Author: Amelia Vidov
• Mentor: Marija Majer (mentor)
• Committee member: Marija Majer (predsjednik povjerenstva)
• Committee member: Maja Planinić (član povjerenstva)
• Committee member: Davor Horvatić (član povjerenstva)
• Committee member: Mihael Makek (član povjerenstva)
• Committee member: Ivica Smolić (član povjerenstva)
• Granter: University of Zagreb; Faculty of Science; (Department of Physics); Zagreb
• Defense date and country: 2019-07-17, Croatia
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Physics

Abstract

Različite energije i vrste zračenja te razvoj novih tehnologija zahtijevaju konstantno usavršavanje dozimetrijskih sustava. Radiofotoluminescentni (RPL) dozimetri su po svojim svojstvima pogodni za upotrebu u mnogim područjima, pogotovo za primjenu u medicini. Za pravilnu primjenu potrebno je poznavati svojstva dozimetara. U ovom radu provjeravala se kutna ovisnost jedne vrste RPL dozimetara (GD-352M) u fotonskim poljima energije 1,25 MeV i 0,661 MeV. Radi kompenziranja poznate energijske ovisnosti na niskim energijama (koje su prisutne u dijagnostičkoj radiologiji ili pri mjerenjima doza izvan ciljnog volumena u radioterapiji) ovi dozimetri imaju dodan kositreni filter. Dozimetri su pripremljeni za mjerenja i nakon zračenja obrađeni u Laboratoriju za radijacijsku kemiju i dozimetriju, a zračeni su u Sekundarnom standardnom dozi-metrijskom laboratoriju Instituta Ruđer Bošković na izvorima 60Co (1,25 MeV) i 137Cs (0,661 MeV). Provjerena je kutna ovisnost na kutevima 0, 15, 30, 45, 60, 75 i 90o. Na kutevima manjim od 45o kutna ovisnost nije uočena za obje energije. Rezultati na većim kutevima pokazali su postojanje kutne ovisnosti samo za fotone niže energije (0,661 MeV). Osim kutne ovisnosti, provjerena je ujednačenost i ponovljivost.

Abstract (english)

Different types of energies and radiation combined with the development of new technologies require constant improvement of dosimetry systems. Radiophotoluminescent (RPL) dosimeters, according to their properties, are suitable for many applications, especially for use in medicine. For proper application it is necessary to know the properties of dosimeters. In this study RPL dosimeters type GD-352M are characterized in terms of angular dependence with two photon energies (1,25 MeV and 0,661 MeV). GD-352M dosimeters have tin filter in order to compensate well known over response in low energy region (typical for diagnostic radiology or outside the target volume in radiotherapy). Dosimeters were prepared for measurements and analyzed after irradiation in the Radiation Chemistry and Dosimetry Laboratory at Ruđer Bošković Institute. Irradiations were performed in the Secondary Standard Dosimetry Laboratory at Ruđer Bošković Institute using 60Co (1,25 MeV) and 137Cs (0,661 MeV) sources. The angular dependence of GD-352M dosimeters was evaluated free in air at angles 0, 15, 30, 45, 60, 75 and 90 degrees. For angles 0 – 45 degrees and both energies, the dosimeters showed no significant angular dependence. However, at higher angles, some angular dependence was observed but only when the dosimeters were irradiated with lower energy (0,661 MeV). In addition to angular dependence, uniformity and reproducibility have been verified.

• Keywords: radiofotoluminescentni dozimetri
• Language: croatian
• URN:NBN: urn:nbn:hr:217:645396
• Study programme: Title: Physics; specializations in: Education; Course: Education; Study programme type: university; Study level: integrated undergraduate and graduate; Academic / professional title: magistar/magistra edukacije fizike (magistar/magistra edukacije fizike)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2019-09-05 12:11:17