Comparison of two extremity dosemeters based on LiF:Mg,Cu,P thin detectors for mixed beta-gamma fields.
Two types of thin LiF:Mg,Cu,P detectors, GR-200F and MCP-Ns, have been characterised for use in the design of an extremity dosemeter for mixed beta-photon radiation fields. Both detectors consist of an extremely thin layer of sensitive material with effective thicknesses of 5 and 8 mg cm(-2), respectively, held in a 5 mg cm(-2) PVC ring holder. Dosimetric performance was analysed according to the ISO 12794 standard and compared with 240 mg cm(-2) TLD-100 measurements. In particular, the energy response was obtained for ISO narrow X-ray spectra, (137)Cs, (60)Co, (204)Tl and (90)Sr/(90)Y. From these measurements a mean calibration factor was calculated to estimate H(p)(0.07). Subsequently, the performance of the dosemeters was checked for a set of 10 different mixed photon and beta-photon fields. The study shows that the proposed dosemeters can estimate H(p)(0.07) in a wide range of mixed beta-photon fields with a maximum deviation from the given dose of 30% and an overall uncertainty of the order of 25% (k = 1). However, the results also highlight a large variability among the different thin detectors and, thus, the standard TLD-100 material is recommended whenever the workplace does not include low-energy beta radiation.
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Institute of Energy Technology (INTE), Technical University of Catalonia (UPC), Diagonal 647, 08028 Barcelona, Spain. merce.ginjaume@upc.es
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D001610:Beta Particles; D003300:Copper / Q000737:chemistry / Q000528:radiation effects; D005459:Fluorides / Q000737:chemistry* / Q000528:radiation effects*; D005720:Gamma Rays; D018020:Lithium Compounds / Q000737:chemistry* / Q000528:radiation effects*; D008274:Magnesium / Q000737:chemistry / Q000528:radiation effects; D008567:Membranes, Artificial; D016273:Occupational Exposure / Q000032:analysis*; D010758:Phosphorus / Q000737:chemistry / Q000528:radiation effects; D011829:Radiation Dosage; D011835:Radiation Protection / Q000295:instrumentation* / Q000379:methods; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013819:Thermoluminescent Dosimetry / Q000295:instrumentation* / Q000379:methods
D018020:Lithium Compounds; D008567:Membranes, Artificial; C027651:lithium fluoride; D010758:Phosphorus; D003300:Copper; D008274:Magnesium; D005459:Fluorides