title: Beta response of LiMgPO4:Tb,B based OSL discs for personnel monitoring applications.
abstract: Properties such as high optically stimulated luminescent (OSL) sensitivity, ease of preparation and dose linearity over nine decades (µGy-kGy) make LiMgPO4:Tb, B (LMP) a unique phosphor for dosimetry applications. This led to the investigation of the beta response of highly sensitive LMP-based Teflon-embedded OSL discs for personnel monitoring applications. A PTB beta secondary standard calibration setup (BSS2), which contains three beta sources viz. (147)Pm, (85)Kr and (90)Sr/(90)Y, was used. The relative response with respect to (137)Cs photons for 0.4-mm thick LMP discs was found to be ∼7.32, ∼53.5 and 100 % for (147)Pm, (85)Kr and (90)Sr/(90)Y beta energies, respectively. The response of LMP discs under various filter combinations viz. 0.18-mm thick mylar (25 mg cm(-2)), 0.625-mm thick Poly-allyl-diglycol carbonate (PADC, 81 mg cm(-2)), 1-mm thick polythene (95 mg cm(-2)), 1-mm thick Perspex (118 mg cm(-2)), 1.25-mm thick PADC (162 mg cm(-2)) and 1.6-mm thick (189 mg cm(-2)) Perspex filters was also studied and the ratio of the response of open disc to the response under filters (DOpen/DFilter) of different thicknesses (mg cm(-2)) was evaluated. Studies were also performed for the mixed field of low- ((85)Kr) and high-energy ((90)Sr/(90)Y) beta particles and the DOpen/DFilter ratio was evaluated. The angular dependence of the response of OSL discs to (85)Kr and (90)Sr/(90)Y beta sources was also studied. Studies were also carried out for (204)Tl, (32)P, natural uranium and (106)Ru/(106)Rh beta sources and the ratios of the response of open disc to that of under 1.6-mm thick Perspex (DOpen/DFilter) filter were measured. A study with various beta sources for the evaluation of the DOpen/DFilter ratio was necessary as these ratios are used to estimate the energy of beta particles and to apply the correction factor while evaluating the beta dose/design of dose estimation algorithms.
authors: Radiological Physics and Advisory Division, Bhabha Atomic Research Centre, Mumbai 400 085, India. munish_pms@rediffmail.com
authors: Munish
authors: M
authors: Kumar
authors: Bhushan
authors: B
authors: Dhabekar
authors: S N
authors: SN
authors: Menon
authors: A K
authors: AK
authors: Bakshi
authors: J
authors: J
authors: Udhayakumar
authors: M P
authors: MP
authors: Chougaonkar
authors: Y S
authors: YS
authors: Mayya
mesh_terms: D000465:Algorithms; D001610:Beta Particles; D001895:Boron / Q000737:chemistry; D002138:Calibration; D004867:Equipment Design; D005373:Film Dosimetry; D006801:Humans; D007194:India; D008094:Lithium / Q000737:chemistry; D008274:Magnesium / Q000737:chemistry; D010756:Phosphoric Acids / Q000737:chemistry; D011138:Polytetrafluoroethylene / Q000737:chemistry; D011829:Radiation Dosage; D012680:Sensitivity and Specificity; D013725:Terbium / Q000737:chemistry; D013819:Thermoluminescent Dosimetry / Q000295:instrumentation* / Q000379:methods*; D013997:Time Factors
chemical_list: D010756:Phosphoric Acids; D013725:Terbium; D011138:Polytetrafluoroethylene; D008094:Lithium; C030242:phosphoric acid; D008274:Magnesium; D001895:Boron