RESUMO
Thermoluminescence (TL) and optically stimulated luminescence (OSL) are the well-known phenomena used for passive methods of dose measurements. TL and OSL detectors are frequently used in the dosimetry of cosmic radiation in space and of particle radiotherapy beams. However, the relative TL/OSL efficiency, which is defined as a ratio of the emitted light intensity per unit dose for a given radiation type, to the same quantity for the reference gamma radiation is not constant and depends on radiation type and energy. In the present work several types of TL and OSL dosimetric materials, including lithium fluoride (LiF), aluminium oxide, beryllium oxide and lithium aluminate, were tested with protons. The measurements were realised exploiting the 60-MeV proton beam of the AIC-144 cyclotron in the Proton Eye Radiotherapy Facility at Institute of Nuclear Physics (IFJ PAN). The influence of proton energy on the relative efficiency and other TL/OSL characteristics of the studied detector types was presented.
Assuntos
Luminescência , Prótons , Dosimetria Termoluminescente/instrumentação , Dosimetria Termoluminescente/métodos , Compostos de Alumínio/química , Óxido de Alumínio/química , Berílio/química , Ciclotrons , Elétrons , Fluoretos/química , Raios gama , Transferência Linear de Energia , Compostos de Lítio/química , Óptica e Fotônica , Fótons , Radiação Ionizante , Radioterapia/métodosRESUMO
A method of measurement of radon concentration in air was developed, based on high-sensitivity LiF:Mg,Cu,P (MCP-N, TLD Poland) thermoluminescent detectors installed in charcoal canisters. The canisters were exposed typically for 72 h in a calibration chamber with a radon concentration ranging from 100 Bq x m(-3) to 87 kBq x m(-3). It was found that in these conditions the signal registered by the TL detectors was proportional to the 222Rn concentration and the lowest limit of detection (LLD) was at a level of 100 Bq x m(-3). The proposed method can be used in large-scale, multi-site surveys aimed at screening for high levels of indoor radon concentration or for measuring ground radon exhalation rates.
Assuntos
Carvão Vegetal/análise , Radônio/análise , Dosimetria Termoluminescente/métodos , Cobre , Desenho de Equipamento , Fluoretos , Compostos de Lítio , Magnésio , Fósforo , Reprodutibilidade dos Testes , Dosimetria Termoluminescente/instrumentaçãoRESUMO
The radiometric K, U and Th concentrations and neutron absorption cross-section sigma a of rock samples obtained from coring are analysed. The cores are from wellbores located in the Sucha-Jordanów region (Carpathian Mountains) and from gas producing Miocene formations in the Carpathian foothills. Correlation coefficients between the neutron absorption cross-section (sigma a) and K, U and Th concentrations are presented. Neural network representation of the function sigma a = f(K, U, Th) obtained for a region can later be used for sigma a estimation from spectrometric probe results in uncored wells.