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Applied Radiation and Isotopes

Mustafa Yiğit
This paper aims the calculations of cross section of the 27 Al(n,t)25 Mg, 50 Cr(n,t)48 V, 56 Fe(n,t)54 Mn, 58 Ni(n,t)56 Co, 64 Zn(n,t)62 Cu, 70 Ge(n,t)68 Ga, 92 Mo(n,t)90 Nb, 106 Cd(n,t)104 Ag and 114 Cd(n,t)112 Ag nuclear reactions. These cross section calculations were obtained using the different level density models in ALICE/ASH code. Besides, the cross sections of the investigated reactions at incident energies near 14.6 MeV were predicted by using the empirical formulae suggested in our previous paper and in the literature...
May 16, 2018: Applied Radiation and Isotopes
T Boshkova
This work proposes a simple way to assess whether a physical effect due to the sample is present, via the relative uncertainty of the measured net signal. A possibility for evaluation of the respective relative limit for any particular (already measured) positive net signal is shown. This relative limit ('relative decision threshold') is strictly related to the basic definition of the decision threshold. The full agreement between the conclusions via the decision threshold and via the relative decision threshold, is experimentally demonstrated...
May 9, 2018: Applied Radiation and Isotopes
Críssia Carem Paiva Fontainha, Neriene Alves, Wilmar Barbosa Ferraz, Luiz Oliveira de Faria
New materials have been widely investigated for ionizing radiation dosimetry for medical procedures. Carbon-doped alumina (α-Al2 O3 :C) have been reported to be excellent thermoluminescent (TL) and optically stimulated luminescence (OSL) radiation dosimeters. In the present study, we have synthetized nano and micro-sized α-Al2 O3 :C polycrystals, doped with different percentages of carbon atoms aiming to compare their efficiency as TL dosimeters. The dosimetric characteristics for X ray and gamma fields were investigated...
May 7, 2018: Applied Radiation and Isotopes
Daniel S Dale, Valeriia N Starovoitova, Tony A Forest, Emily Oliphant
The use of fracing has risen over the past decade and revolutionized energy production in the US. However, there is still an impetus for further optimization of the extraction of oil and natural gas from vast shale reservoirs. In this work, we discuss photonuclear production of yttrium-88 as a promising radiotracer for fracing operations. Single neutron knock-out from natural monoisotopic yttrium-89 is an inexpensive process resulting in high activity of 88 Y with minimal impurities. MCNPX simulations were performed to estimate the 88 Y yield...
May 5, 2018: Applied Radiation and Isotopes
J M Lopes, M P C Medeiros, R W D Garcêz, R A Filgueiras, J L Thalhofer, W F R Silva Júnior, A X Silva
Self-absorption correction factors are fundamental in spectroscopy to correct the efficiency of the samples detection whose density is different from the radioactive standard. Mathematical simulations have been widespread as a tool to facilitate the procedure of correction factors calculation. In this paper, LabSOCS was used to calculate the self-absorption correction factor for some geometries and the values found were compared to those obtained in MCNP and experimental values. The percentage deviations found for the self-absorption correction factor calculated by LabSOCS were below 1...
May 5, 2018: Applied Radiation and Isotopes
Rupa Sarkar, Prasanna Kumar Mondal, Barun Kumar Chatterjee
The response of superheated droplet detectors (SDD) loaded with four different active liquids, R-12 (CCl2 F2 ), R-114 (C2 Cl2 F4 ), R-134a (C2 H2 F4 ) and R-610 (C4 F10 ) have been studied to obtain the gamma ray detection threshold temperature (Tγ ) of the respective detectors. A 137 Cs gamma ray source is used for this study. To obtain Tγ from the experimental data a phenomenological model has been used. Result indicates that Tγ maintains a linear relationship with the limit of superheat (Tlim ) of different active liquids used in SDD...
May 3, 2018: Applied Radiation and Isotopes
M Shoji, T Aso, M Hara, R Benii, Y Kato, T Furusawa, T Yoshimura
The 125 I pulse-height spectra via a liquid scintillation counter (LSC) displayed notable variations. The counting efficiencies of higher and lower energy peaks increased and decreased, respectively, with the enhancement of the amount of high atomic numbered elements within the cocktails. This tendency was ascribed to the increasing probability of the interaction of photons with the scintillation cocktail. Moreover, it was noted that the shape of a 125 I spectrum strongly depends on the amount of high atomic numbered elements...
May 2, 2018: Applied Radiation and Isotopes
Mostafa Robatjazi, Hamid Reza Baghani, Seied Rabi Mahdavic, Giuseppe Felici
A shielding disk is used for IOERT procedures to absorb radiation behind the target and protect underlying healthy tissues. Setup variation of shielding disk can affect the corresponding in-vivo dose distribution. In this study, the changes of dosimetric parameters due to the disk setup variations is evaluated using EGSnrc Monte Carlo (MC) code. The results can help treatment team to decide about the level of accuracy in the setup procedure and delivered dose to the target volume during IOERT.
May 1, 2018: Applied Radiation and Isotopes
A Zhukouski, O Anshakou, S Kutsen
A gamma spectrometric method is presented for in situ radiation monitoring of bottom sediments with contaminated layer of unknown thickness to be determined. The method, based on the processing of experimental spectra using the results of their simulation by the Monte Carlo method, is proposed and tested in practice. A model for the transport of gamma radiation from deposited radionuclides 137 Cs and 134 Cs to a scintillation detection unit located on the upper surface of the contaminated layer of sediments is considered...
April 30, 2018: Applied Radiation and Isotopes
H Olaya Davila, S A Martínez-Ovalle, H F Castro Serrato, H R Vega-Carrillo
A bimodal tomographic system with a RTW MCBM 65B-50Mo X-ray tube and a XPAD3s semiconductor camera that contains 8 bars, each one with 67,200 hybrid pixels are modeled in GEANT4 simulation code. Several conical X-ray spectra were simulated, particularly a spectrum with a peak energy of 17.4 keV used in tomography on small animals. Three phantoms located in the tomographic center were added to the simulation to evaluate the image quality and its magnification based on the simulation of different photon fluences and the rotation effect of the tomographic system with an average angular velocity of 360o per minute...
April 28, 2018: Applied Radiation and Isotopes
Pauli Peura, Camille Bélanger-Champagne, Paula Eerola, Peter Dendooven, Eero Huhtalo
A thin 5-mm NaI(Tl) scintillator detector was tested with the goal of enhancing the detection efficiency of 241 Am gamma and X rays for steelworks operations. The performance of a thin (5 mm) NaI(Tl) detector was compared with a standard 76.2-mm thick NaI(Tl) detector. The 5-mm thick detector crystal results in a 55% smaller background rate at 60 keV compared with the thicker detector, translating into the ability to detect 30% weaker 241 Am sources. For a 5 mm thick and 76.2 mm diameter NaI detector in the ladle car tunnel at Outokumpu Tornio Works, the minimum activity of a molten 241 Am source that can be detected in 5 s with 95% probability is 9 MBq...
April 26, 2018: Applied Radiation and Isotopes
S Savoye, A Rajyaguru, N Macé, S Lefèvre, G Spir, J C Robinet
This work presents two complementary approaches (for low and high desaturation) to study tritiated water (HTO) diffusion through unsaturated cement-based materials. The first approach was based on through-diffusion experiments where suction was controlled by osmosis. In the second approach, diffusion experiments were performed in humidity chambers controlled by under-saturated saline solutions. Results revealed a decrease of effective diffusion coefficient by a factor of 10 from 100% to 23% of saturation degree...
April 26, 2018: Applied Radiation and Isotopes
Sudipta Chakraborty, K V Vimalnath, Rubel Chakravarty, H D Sarma, Ashutosh Dash
Lutetium-177-labeled PSMA inhibitor has emerged as a promising modality for targeted therapy of prostate carcinoma. A protocol for regular multidose formulation of ready-to-use 177 Lu-PSMA-617 has been developed based on detailed and systematic radiochemical investigations. The formulation meets the requirements of clinical use and can be shipped to nuclear medicine centres for administration up to 4 days from the date of formulation. The reported protocol would be useful toward facilitating widespread clinical utilization of 177 Lu-PSMA-617 in the management of prostate cancer...
April 26, 2018: Applied Radiation and Isotopes
Mark A Prelas, Modeste Tchakoua Tchouaso
This paper discusses the use of one of the safest isotopes known isotopes, Kr-85, as a candidate fuel source for deep space missions. This isotope comes from 0.286% of fission events. There is a vast quantity of Kr-85 stored in spent fuel and it is continually being produced by nuclear reactors. In using Kr-85 with a novel Dual Cycle Conversion System (DCCS) it is feasible to boost the system efficiency from 26% to 45% over a single cycle device while only increasing the system mass by less than 1%. The Kr-85 isotope is the ideal fuel for a Photon Intermediate Direct Energy Conversion (PIDEC) system...
April 26, 2018: Applied Radiation and Isotopes
Modeste Tchakoua Tchouaso, Haruetai Kasiwattanawut, Mark A Prelas
This paper demonstrates the ability of diamond sensors to respond to beta radiation. A Chemical Vapor Deposition (CVD) single crystal diamond was used in this work. The diamond crystal has a dimension of 4.5×4.5 by 0.5 mm thick. Metal contacts were fabricated on both sides of the diamond using titanium and palladium metals with thicknesses of 50 nm and 150 nm, respectively. The energy response of the diamond sensor was experimentally measured using three beta isotopes that cover the entire range of beta energy: 147 Pm, a weak beta radiation with a maximum energy of 0...
April 26, 2018: Applied Radiation and Isotopes
M Pilakouta, F K Pappa, D L Patiris, C Tsabaris, C A Kalfas
A methodology that extends the usability of low and medium resolution γ-ray detectors to a wide range of energies that appear in environmental radioactivity measurements is described. Results of the implementation of the methodology in the analysis of 20 granite samples measured with a (3″ × 3″) NaI(Tl) are presented. A comparison with the activity results obtained by a high-resolution detector (HPGe) for two samples was found in good agreement, within the uncertainties, validating the results of the proposed method...
April 25, 2018: Applied Radiation and Isotopes
Jierui Zou, Junwang Guo, Guofu Dong, Lei Ma, Jianbo Cong, Ye Liu, Ye Tian, Ke Wu
The X-band in vivo EPR tooth dosimetry is promising as a tool for the initial triage after a large-scale radiation accident. The dielectric losses caused by water on the tooth surface (WTS) are one of the major sources of inaccuracies in this method. The effect was studied by theoretical simulation calculations and experiments with water films of various thicknesses on teeth. The results demonstrate the possibility of sufficiently accurate measurements of the radiation-induced signal of the tooth enamel provided that the thickness of the water film on the tooth is below 60 µm...
April 24, 2018: Applied Radiation and Isotopes
Yihunie Hibstie Asres, Manny Mathuthu, Marelgn Derso Birhane
This study provides current evidence about cross-section production processes in the theoretical and experimental results of neutron induced reaction of uranium isotope on projectile energy range of 1-100 MeV in order to improve the reliability of nuclear stimulation. In such fission reactions of 235 U within nuclear reactors, much amount of energy would be released as a product that able to satisfy the needs of energy to the world wide without polluting processes as compared to other sources. The main objective of this work is to transform a related knowledge in the neutron-induced fission reactions on 235 U through describing, analyzing and interpreting the theoretical results of the cross sections obtained from computer code COMPLET by comparing with the experimental data obtained from EXFOR...
April 22, 2018: Applied Radiation and Isotopes
Samira Abbaspour, Kaveh Tanha, Babak Mahmoudian, Majid Assadi, Jalil Pirayesh Islamian
Collimator geometry has an important contribution on the image quality in SPECT imaging. The purpose of this study was to investigate the effect of parallel hole collimator hole-size on the functional parameters (including the spatial resolution and sensitivity) and the image quality of a HiReSPECT imaging system using SIMIND Monte Carlo program. To find a proper trade-off between the sensitivity and spatial resolution, the collimator with hole diameter ranges of 0.3-1.5 mm (in steps of 0.3 mm) were used with a fixed septal and hole thickness values (0...
April 22, 2018: Applied Radiation and Isotopes
Tzinnia Gabriela Soto-Bernal, Antonio Baltazar-Raigosa, Diego Medina-Castro, Hector Rene Vega-Carrillo
The characteristics of photons and neutrons produced during the interaction between a monoenergetic (12 and 18 MeV) electron beam and a tungsten scattering foil enclosed into a 10 cm-thick tungsten shell have been determined using Monte Carlo methods. This model was used aiming to represent a linac head working in electron-mode for cancer treatment. Photon and neutron spectra were determined around the scattering foil and to 50 and 100 cm below the electron source. Induced photons are mainly produced along the direction of the incoming electron beam...
April 18, 2018: Applied Radiation and Isotopes
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