Browsing by Author "Akar Tarim U."

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Evaluation of radon concentration in well and tap waters in Bursa, Turkey
(2012-06-01) Akar Tarim U.; Gurler O.; Akkaya G.; Kilic N.; Yalcin S.; Kaynak G.; Gundogdu O.
222Rn measurements in water samples collected from 27 wells and 19 taps that were supplied from the investigated wells were conducted using the AlphaGUARD PQ 2000PRO radon gas analyser at sites across several geologic formations within the city of Bursa, Turkey. The measured radon concentrations ranged from 1.46 to 53.64 Bq l -1 for well water and from 0.91 to 12.58 Bq l -1 for tap water. Of the 27 sites sampled, only 7 had radon levels above the safe limit of 11.1 Bq l -1 recommended by the USEPA. In general, all determined concentrations were well below the 100 Bq l -1 revised reference level proposed by the European Union. These values of radon concentrations in water samples are compared with those reported from other countries. Doses resulting from the consumption of these waters were calculated. The minimum and the maximum annual mean effective doses due to 222Rn intake through water consumption were 0.02 mSv a -1 and 1.11 mSv a -1, respectively. © The Author 2011. Published by Oxford University Press.
Indoor radon levels in primary and secondary schools of Kastamonu, Turkey
(2015-01-01) Yalcin S.; Aras G.; Akar Tarim U.; Gurler O.
In this study, indoor air radon concentrations in the primary and secondary school buildings in the province of Kastamonu in Turkey were measured using AlphaGUARD PQ2000 PRO radon detector. The goal of this survey was to assess the radon concentration in the schools of this city. The research was focused on the age of the buildings and building materials affecting radon concentration levels. The results were not conclusive, activities were measured in the range of 11.87 ± 5.53 to 58.98 ± 19.77 Bq m-3. This range is well below the recommended reference levels for houses and workplaces.
Monte Carlo analyses of multiple backscattering of gamma rays
(2013-02-01) Akar Tarim U.; Ozmutlu E.; Gurler O.; Yalcin S.
We have written a Monte Carlo code to simulate the experimental results of a previously reported study. We were able to analyse the energy distributions of photons that reached the detector system after suffering several successive Compton scatterings in the target. We have also investigated how the number of multiply backscattered events depends on the target thickness and the energy of the primary photons. © 2012 Akadémiai Kiadó, Budapest, Hungary.
Monte Carlo modelling of single and multiple Compton scattering profiles in a concrete material
(2013-04-01) Akar Tarim U.; Ozmutlu E.; Gurler O.; Yalcin S.; Gundogdu O.; Sharaf J.; Bradley D.
A Monte Carlo simulation study has been conducted of 60Co photons Compton scattered in concrete, illustrating the degraded energy spectra of gamma-ray radiation. Results are produced representing a NaI(Tl) detector model. We were able to analyse energy distributions of photons that reach the detector system after suffering several successive Compton scatterings in the target. The predicted decrease in intensity of single- and multiple-scattering peaks with increase in thickness of the target medium are in good agreement with experimental observations and findings reported by others. © 2012 Elsevier Ltd.
The effect of the housing material on the NaI(Tl) detector response function
(2012-07-01) Akar Tarim U.; Ozmutlu E.; Gurler O.; Yalcin S.
In this study, a Monte Carlo program has been developed to simulate the response function of the NaI(Tl) detector with all features for 60Co and 137Cs and to investigate the effects of detector housing material on response function. The pulse height spectra in a 2″ × 2″ NaI(Tl) detector due to these gamma ray sources have been measured. Comparison of the experimentally obtained and simulated spectra shows that there is good agreement between both spectra. Energy distributions of gamma photons that generate the backscattering peak in the response function were obtained and the contribution of single, double and multiple Compton scattering events to these distributions was investigated. © 2012 Akadémiai Kiadó.
The energy spectrum of 662keV photons in a water equivalent phantom
(2012-01-01) Akar Tarim U.; Gurler O.; Ozmutlu E.; Yalcin S.; Gundogdu O.; Sharaf J.; Bradley D.
Investigation is made on the energy spectrum of photons originating from interactions of 662. keV primary gamma-ray photons emitted by a point source positioned at the centre of a water equivalent solid phantom of dimensions 19. cm×19. cm×24. cm. Peaks resulting from total energy loss (photopeak) and multiple and back scattering have been observed using a 51. mm×51. mm NaI(Tl) detector; good agreement being found between the measured and simulated response functions. The energy spectrum of the gamma photons obtained through the Monte Carlo simulation reveals local maxima at about 100. keV and 210. keV, being also observed in the experimental response function. Such spectra can be used as a method of testing the water equivalence of solid phantom media before their use for dosimetry measurements. © 2012 Elsevier Ltd.