Passive system characterizing the spectral composition of high dose rate workplace fields: Potential application of high Z OSL phosphors. (November 2017)

• Record Type: Journal Article
• Authors: Chumak, V.; Morgun, A.; Zhydachevskii, Ya.; Ubizskii, S.; Voloskiy, V.; Bakhanova, O.
• Is Part Of: Radiation measurements. Volume 106(2017:Nov.)
• Page Start: 638
• Page End: 643
• Publication Date: 2017-11
• Subjects: Photons -- Energy -- Passive detectors -- Spectrum -- Luminescence; Nuclear emulsions -- Periodicals; Particle tracks (Nuclear physics) -- Periodicals; Thermoluminescence -- Periodicals; Cosmic rays -- Periodicals; Radiation -- Measurement -- Periodicals; Radiometry -- Periodicals; Radiation Monitoring -- Periodicals; Émulsions nucléaires -- Périodiques; Particules (Physique nucléaire) -- Traces -- Périodiques; Thermoluminescence -- Périodiques; Rayonnement cosmique -- Périodiques; Radiométrie -- Périodiques; 539.77
• DOI: 10.1016/j.radmeas.2017.07.008
• Languages: English
• ISSNs: 1350-4487

Abstract

Abstract: The problem of the deconvolution of incident photon spectra in high dose rate fields, where active in situ spectrometers fail, is addressed by application of a passive system, consisting of a number of detectors with different energy responses, which are exposed simultaneously while the deconvolution of photon spectra is performed by solving a set of simultaneous linear equations. In recent years, the practical variety of TL/OSL detectors has been broadened, including such materials as Al 2 O 3 :C, BeO and, most important, new materials with high effective atomic number Z eff : YAlO 3 :Mn 2+ with Z eff = 31.4 and Lu 2 O 3 with Z eff = 67.3, which demonstrate significant energy response (up to 50x) at lower energies. The use of these materials allows to apply the deconvolution methodology with better accuracy and energy resolution in the region of lower (below 150 keV) photon energies. The paper provides theoretical substantiation of this methodology and considers the application of a variety of 'attenuator-detector' combinations for better resolution of photon spectra. With respect to overall uncertainty, the results of the Monte Carlo simulation of 'model' spectra ranging from 10 keV to 1.8 Mev and of their deconvolution performed with respect to possible measurement error demonstrates the robustness and adequate accuracy of the proposed approach. Highlights: The methodology is proposed for determination of the photon energy composition of workplace fields in a very broad range of ambient dose rates. The use of new OSL materials with pronounced energy response allows: Enhanced robustness of results and lower uncertainty of ambient energy deconvolution. Possibility of finer resolution of the workplace ambient photon spectrum. Passive detectors provide operation in broader range of doses and dose rate fields.