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Applied Radiation and Isotopes

K Belkadhi, K Elhamdi, M Bhar, K Manai
In this work, we focus on the buildup correction of dose calculation using Haar wavelets in the Tunisian gamma irradiation facility. The buildup effect of gamma rays was used to adjust absorbed dose calculation for different depth in the irradiated products. A buildup study with different product densities was carried out to generalize the dose adjustment approach to any product at any depth.
June 15, 2017: Applied Radiation and Isotopes
Karsten Kossert, Justyna Marganiec-Gałązka, Xavier Mougeot, Ole J Nähle
The activity concentration of a (60)Co solution was measured by means of two 4πβ-γ coincidence counting systems using a liquid scintillation counter and a proportional counter (PC) in the beta channel, respectively. Additional liquid scintillation measurements were carried out and CIEMAT/NIST efficiency tracing as well as the triple-to-double coincidence ratio (TDCR) methods were applied to analyse the data. The last two methods require computed beta spectra to determine the counting efficiencies. The results of both 4πβ-γ coincidence counting techniques are in very good agreement and yield a robust reference value...
June 15, 2017: Applied Radiation and Isotopes
Karl-Heinz Hellmuth, Marja Siitari-Kauppi, Hannu Arvela, Antero Lindberg, Lionel Fonteneau, Paul Sardini
Radon emanation from intact samples of fresh ("BG"), altered ("Fract") and disturbed ("EDZ") Finnish granitic rock from Kuru (Finland) and its dependence on humidity and rock structural factors was studied. The pore network of the rock was characterized by microscopy and impregnation with (14)C-PMMA (polymethylmethacrylate) resin and autoradiography. The radon emanation factor was increasing linearly with the relative humidity. (14)C-PMMA autoradiography of the altered zones and the EDZ indicated significant, mineral-specific increase of porosity and porosity gradients towards the fracture surfaces (Fract) and microcracks within the EDZ...
June 13, 2017: Applied Radiation and Isotopes
Z J Sun, K Okafor, S Isa
In photon activation, same element may be activated by the bremsstrahlung beam through different nuclear reaction channels and produce different radioisotopes. These radioisotopes follow their own decay schemes and generate characteristic gamma rays. This phenomenon usually is an interference in spectra analysis, but it also offers a theoretical feasibility to determine the concentration of one element through different reaction channels. To realize this theoretical feasibility, we conducted series of photon activation experiments with sample and reference of known concentrations...
June 13, 2017: Applied Radiation and Isotopes
Ozan Artun
In the present study, we aimed at estimating the production of medical Ac-225 radionuclide via proton accelerator in the energy range Eproton=1000 →1MeV under certain conditions, on thorium target material instead of uranium due to the low abundant of uranium in nature. Hence, to produce the medical Ac-225, cross-section, separation energy was calculated by taking into account the proton induced reaction processes that were simulated to estimate activity and, yield of the product up to 1000MeV. Moreover, the calculated integral yields of reactions were presented...
June 10, 2017: Applied Radiation and Isotopes
Sonali Gaikwad, R R Patil, M S Kulkarni, S V Moharil
Optically stimulated luminescence (OSL) was studied in rare earth doped SrBPO5 for the possible applications in radiation dosimetry using optically stimulated luminescence. The study shows that the sensitivity of the Eu doped SrBPO5 shows good OSL and the sensitivity is comparable to that of Al2O3:C. It is observed that annealing has a profound effect on the OSL sensitivity. Slowly cooled Eu doped sample shows highest sensitivity and is 77% compared to that Al2O3:C whereas lowest sensitivity is observed in the quenched sample...
June 9, 2017: Applied Radiation and Isotopes
G W Hitt, B Goddard, A A Solodov, D Bridi, A F Isakovic, R El-Khazali
Recent reports of Solar modulation of beta-decay have reignited interest in whether or not radioactive half-lives are constants. A numerical approach for filtering instrumental effects on residuals is developed, using correlations with atmospheric conditions recorded while counting (204)Tl emissions with a Geiger-Müller counter. Half-life oscillations and detection efficiency oscillations can be separated provided their periods are substantially different. A partial uncertainty budget for the (204)Tl half-life shows significant decreases to medium-frequency instabilities correlated with pressure and temperature, which suggests that further development may aid general improvements in half-life determinations...
June 9, 2017: Applied Radiation and Isotopes
L Pibida, L King
The National Institute of Standards and Technology (NIST) compared the measured full-energy peak efficiency obtained from a large set of sources to that of a (207)Bi source obtained using three different half-life values. The values of the half-life used for this comparison are published in the Decay Data Evaluation Project (32.9 ± 1.4) years and the Evaluated Nuclear Structure Data File (31.55 ± 0.4) years, and in a recent NIST publication (31.20 ± 0.05) years (or (11395 ± 18) days).
June 9, 2017: Applied Radiation and Isotopes
Mozhgan Sharifian, Mahdi Sadeghi, Behrouz Alirezapour
The (89)Zr, is one of the radionuclide with near-ideal properties for PET due to its suitable half-life and decay properties. The cross-section of (89)Zr via (89)Y(p,n)(89)Zr, (89)Y(d,2n)(89)Zr, (nat)Sr(α,xn)(89)Zr and (nat)Zr(p,pxn)(89)Zr, were calculated by the TALYS-1.8 code to predict the optimum range of charge particle energy. The Monte Carlo code GEANT4 was used to simulate the formation of (89)Zr in the target body. The simulated (89)Zr yield was in good agreement with published experimental results in the optimum energy range...
June 9, 2017: Applied Radiation and Isotopes
E Yilmaz, A Kahraman, A M McGarrigle, N Vasovic, D Yegen, A Jaksic
The irradiation response of Radiation Sensing Field Effect Transistor (RadFET), also known as MOSFET/pMOS dosimeter, to high energy X-rays and electron beams was investigated. The threshold voltages before and after irradiation were measured and the trap densities in the gate oxide and oxide/silicon interface of the RadFETs are evaluated. The RadFETs were irradiated with 6MV X-rays, and 10 and 18MeV electron beams emitted from a Linear accelerator (LINAC). Linear and non-linear fits to experimental results showed that after an initial linear response up to several Gy, deviation from the linearity occurred due to electric field screening by the radiation induced oxide trapped charges...
June 8, 2017: Applied Radiation and Isotopes
B Zaffora, M Magistris, G Saporta, J-P Chevalier
This paper describes the process adopted at the European Organization for Nuclear Research (CERN) to quantify uncertainties affecting the characterization of very-low-level radioactive waste. Radioactive waste is a by-product of the operation of high-energy particle accelerators. Radioactive waste must be characterized to ensure its safe disposal in final repositories. Characterizing radioactive waste means establishing the list of radionuclides together with their activities. The estimated activity levels are compared to the limits given by the national authority of the waste disposal...
June 3, 2017: Applied Radiation and Isotopes
Rajnikant Makwana, S Mukherjee, L Snoj, S S Barala, M Mehta, P Mishra, S Tivari, M Abhangi, S Khirwadkar, H Naik
Neutron induced nuclear reactions are of prime importance for both fusion and fission nuclear reactor technology. Present work describes the first time measurement of spectrum average cross section of nuclear reactions (183)W(n,p)(183)Ta and (184)W(n,p)(184)Ta using (252)Cf spontaneous fission neutron source. Standard neutron activation analysis (NAA) technique was used. The neutron spectra were calculated using Monte Carlo N Particle Code (MCNP). The effects of self-shielding and back scattering were taken into account by optimizing the detector modeling...
June 2, 2017: Applied Radiation and Isotopes
W Melo-Bernal, V Chernov, G Chernov, M Barboza-Flores
In this study, an analytical model for the assessment of the modification of cell culture survival under ionizing radiation assisted with nanoparticles (NPs) is presented. The model starts from the radial dose deposition around a single NP, which is used to describe the dose deposition in a cell structure with embedded NPs and, in turn, to evaluate the number of lesions formed by ionizing radiation. The model is applied to the calculation of relative biological effectiveness values for cells exposed to 0.5mg/g of uniformly dispersed NPs with a radius of 10nm made of Fe, I, Gd, Hf, Pt and Au and irradiated with X-rays of energies 20keV higher than the element K-shell binding energy...
May 31, 2017: Applied Radiation and Isotopes
J C Hardy, N Nica, V E Iacob, M B Trzhaskovskaya
We have been testing the theory used to calculate internal-conversion coefficients (ICCs) by making a series of measurements of αK values with precision better than ±2%. So far we have measured E3 transitions in three nuclei, (103)Rh, (111)Cd and (134)Cs; and M4 transitions in six nuclei, (119)Sn, (125)Te, (127)Te, (137)Ba, (193)Ir and (197)Pt. Together, these span a wide range of A and Z values. In all cases, the results strongly favor Dirac-Fock calculations in which the final-state electron wave function has been computed in an atomic field that includes the vacancy created by the internal-conversion process...
May 31, 2017: Applied Radiation and Isotopes
Seyedeh Fatemeh Hosseini, Mohammadreza Aboudzadeh, Mahdi Sadeghi, Ahmad Ahmadi Teymourlouy, Malihe Rostampour
(67)Cu radioisotope is a beta particle-emitting nuclide used in radioimmunotherapy (RIT) as well as for imaging, tracer kinetic studies and dosimetry. (67)Cu can be produced by bombarding (nat)Zn with deuterons. In this study, the physical yields of (67)Cu via (nat)Zn(d,x)(67)Cu reaction channel as well as via subreactions of (68)Zn(d,2pn)(67)Cu, (67)Zn(d,2p)(67)Cu, (70)Zn(d,2p3n)(67)Cu, (68)Zn(d,x)(67)Ni(T1/2=21s)→(67)Cu and (70)Zn(d,x)(67)Ni(T1/2=21s)→(67)Cu in the (nat)Zn target have been calculated by using the MCNPX-2...
May 31, 2017: Applied Radiation and Isotopes
J L Ma, Q Yue, Q Wang, J Li, H T Wong, S T Lin, S K Liu, L Wang, H Jiang, L T Yang, L P Jia, J H Chen, W Zhao
The characteristics of the surface inactive layer of a 1-kg-mass p-type point-contact germanium detector were studied. The thickness of the inactive layer and its uniformity on the top and lateral surfaces were measured. A charge collection efficiency function was developed according to the Monte Carlo simulation to describe the charge collection capacity along the depth within this inactive layer. In the energy range below 18keV, the surface, bulk, and total spectra of (57)Co, (133)Ba, (137)Cs, and (60)Co from simulations based on the charge collection efficiency function were well consistent with those from experiments...
May 30, 2017: Applied Radiation and Isotopes
M Y Nadar, D K Akar, D D Rao, M S Kulkarni, K S Pradeepkumar
Various parameters can introduce uncertainties in the lung activity measurements of actinides. In this study, uncertainties due to non-uniform distribution of activity in the lungs are evaluated. To study the effect of non-uniform distribution, lungs of ICRP male thorax voxel and resized phantoms are divided into upper and lower parts of both right and left lungs as well as into anterior and posterior lung regions. Simulation of uniform and non-uniform distribution of activity in lungs is carried out using thorax voxel phantoms in FLUKA for Phoswich and an array of three HPGe detectors for 18-238keV photons...
May 25, 2017: Applied Radiation and Isotopes
G Cedillo Del Rosario, E Cruz-Zaragoza, M García Hipólito, J Marcazzó, J M Hernández A, H Murrieta S
Zinc borate, Zn(BO2)2, doped with different concentrations of terbium (0.5-8mol%) was synthesized and polycrystalline samples were characterized by Scanning Electron Microscopy and X-Ray Diffraction. The Zn(BO2)2 was formed in the pure samples sintered at 750 and 800°C which has the body centered cubic structure, and a ZnB4O7 primitive orthorhombic phase was present. The thermoluminescent intensity was dependents on the thermal treatment (250-500°C) and also on the impurity concentration. The linear dose-response was obtained between 0...
May 24, 2017: Applied Radiation and Isotopes
Seyedeh Fatemeh Hosseini, Mahdi Sadeghi, Mohammad Reza Aboudzadeh
(47)Sc radioisotope with beta particle emission can be used for targeted radionuclide therapy in nuclear medicine and can be produced by nuclear reactor (with high activities) and accelerator. In this work, the specific activity of (47)Sc with the isotopic impurities produced through irradiating the enriched (47)Tio2 and natural TiO2 targets have been calculated by the MCNPX-2.6 and the TALYS-1.8 codes and also theoretical approach in a fast neutron flux 3×10(13)ncm(-2)s(-1) in the reactor. In addition, the cross sections of (46)Ti(n,p)(46)Sc reaction have been interpolated in the 1-10MeV energy range and compared with the corresponding experimental data, as well...
May 23, 2017: Applied Radiation and Isotopes
N Lakshminarayanan, Amit Kumar, Sushant Roy, Yogita Pawar, Pradip Chaudhari, M G R Rajan
O-(2'-[(18)F]fluoroethyl)-l-tyrosine is reportedly suitable for PET-imaging of brain tumours. We report here the synthesis of Ni(II)-complex of Schiff's base (S)-[N-2-(N'-benzylprolyl)amino]-benzophenone,((S)BPB) and alkylated l-tyrosine precursor, Ni(II)-(S)-BPB-l-Tyr-O-CH2-CH2-OTs by an improved method. A fully-automated radio-synthesis including non-HPLC purification was developed with a radio-chemical yield of 24.6 ± 2% in 70 ± 2min (n = 5). Radiochemical and enantiomeric purity was > 98% and 94% respectively...
May 22, 2017: Applied Radiation and Isotopes
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