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Applied Radiation and Isotopes

M A de León-Alfaro, A Morales-Hernández, J Roman-Lopez, J Zarate-Medina, T Rivera-Montalvo
This paper reports on an investigation into the thermally stimulated luminescence (TL) and optically stimulated luminescence (OSL) characteristics of novel luminescent phosphor. A new Pr(3+)-doped, lanthanum aluminate (LaAlO3)-based luminescent phosphor is developed. Samples of LaAlO3:Pr(3+) were irradiated to beta doses, in air, from 0.1Gy up to 50Gy and then were analyzed using both TL and continuous wavelength OSL (CW-OSL) techniques to determine their luminescent characteristics. This phosphor shows a TL glow curve, after its irradiation to beta radiation, with two TL peaks: one located around 160°C and a second at 300°C...
November 14, 2017: Applied Radiation and Isotopes
A J Fenwick, J L Wevrett, K M Ferreira, A M Denis-Bacelar, A P Robinson
In External Beam Radiotherapy, National Metrology Institutes (NMIs) play a critical role in the delivery of accurate absorbed doses to patients undergoing treatment. In contrast for nuclear medicine the role of the NMI is less clear and although significant work has been done in order to establish links for activity measurement, the calculation of administered absorbed doses is not traceable in the same manner as EBRT. Over recent decades the use of novel radiolabelled pharmaceuticals has increased dramatically...
November 11, 2017: Applied Radiation and Isotopes
Martin Schulc, Michal Košťál, Stanislav Simakov, Vojtěch Rypar, Davit Harutyunyan, Jan Šimon, Nicola Burianová, Evžen Novák, Bohumil Jánský, Martin Mareček, Jan Uhlíř
The results of systematic evaluations of the spectrum-averaged cross section measurements performed in the spontaneous fission (252)Cf neutron field are presented. The Following threshold reactions were investigated: (23)Na(n,2n)(22)Na, (54)Fe(n,p)(54)Mn, (54)Fe(n,α) (51)Cr, (27)Al(n,p)(27)Mg, (27)Al(n,α)(24)Na, (19)F(n,2n)(18)F, (90)Zr(n,2n)(89)Zr and (89)Y(n,2n)(88)Y. The spectrum-averaged cross sections for (23)Na(n,2n)(22)Na, (54)Fe(n,α)(51)Cr and (89)Y(n,2n)(88)Y reactions were measured for the first time...
November 8, 2017: Applied Radiation and Isotopes
Yan Zhang, WenBao Jia, Robin Gardner, Qing Shan, Daqian Hei
In the present work, a prompt gamma neutron activation analysis (PGNAA) setup, which consists of a 300mCi (241)Americium-Beryllium (Am-Be) neutron source and a 4 × 4-in. Bismuth germanium oxide (BGO) detector, was developed for heavy metal detection in aqueous solutions. A series of standard samples with analytical purity were prepared by dissolving heavy metals in deionized water. Quantitative spectrum analysis was performed by the Monte Carlo-Least-Squares (MCLLS) approach to measure the standard samples...
November 7, 2017: Applied Radiation and Isotopes
Xiaohong Wang, Wenzhi Xu, Caihong Miao, Fugui Dong, Wei Li, Min Wang, Mingzhang Gao, Qi-Huang Zheng, Zhidong Xu
The reference standard N-(3-(4-methylpiperazin-1-yl)-1-(5-methylpyridin-2-yl)-1H-pyrazol-5-yl)pyrazolo[1,5-a]pyrimidine-3-carboxamide (9) and its demethylated precursor N-(1-(5-methylpyridin-2-yl)-3-(piperazin-1-yl)-1H-pyrazol-5-yl)pyrazolo[1,5-α]pyrimidine-3-carboxamide (8) were synthesized from pyrazolo[1,5-a]pyrimidine-3-carboxylic acid and ethyl 2-cyanoacetate with overall chemical yield 13% in nine steps and 14% in eight steps, respectively. The target tracer N-(3-(4-[(11)C]methylpiperazin-1-yl)-1-(5-methylpyridin-2-yl)-1H-pyrazol-5-yl)pyrazolo[1,5-a]pyrimidine-3-carboxamide ([(11)C]9) was prepared from its precursor with [(11)C]CH3OTf through N-[(11)C]methylation and isolated by HPLC combined with SPE in 50-60% radiochemical yield, based on [(11)C]CO2 and decay corrected to EOB...
November 6, 2017: Applied Radiation and Isotopes
Ryan Clanton, Arnulfo Gonzalez, Sriram Shankar, Gamal Akabani
The selective delivery of radionuclides to tissues of interest remains a problematic task during treatment. The lack of tissue specificity for many therapeutics limit their efficacy by putting healthy organs and tissues at risk (e.g., side effects). Therefore, high specificity therapeutic strategies are needed to overcome these risks. The objective of this study was to use a modified citrate reduction technique to synthesize gold nanoparticles (AuNPs) containing (125)I in order to combine their unique therapeutic and diagnostic properties...
November 6, 2017: Applied Radiation and Isotopes
Stefano Bianchi, Alessandro Longo, Wolfango Plastino, Pavel P Povinec
Time series analysis of (7)Be and (133)Xe atmospheric data and meteorological parameters measured at four CTBTO/IMS radionuclide stations have shown great variability in terms of noise structures, harmonic content, cross-correlation patterns and local Hurst exponent behaviour. This study focused on highlighting and characterising both differences and similarities expected for these radionuclides due to their different physical and chemical characteristics along with their different source terms. Detrended crosscorrelation analysis of different meteorological parameters influencing the residuals time series has shown that for Canadian and American stations the parameters mostly affecting radionuclide concentrations in the air seem to be wind direction and atmospheric pressure...
November 2, 2017: Applied Radiation and Isotopes
Milić M Pejović, Svetlana M Pejović
Performance of a commercial p-channel power vertical-double-diffusion metal-oxide-semiconductor field-effect transistors (VDMOSFETs) as a γ-radiation dosimeters were studied. The devices were irradiated with (60)Co to 10-50Gy at the gate biases ranging from 0 to 5V, and subsequent dosimetric signal fading was monitored during room-temperature storage without a gate bias for 100 days. A linear relationship was found between the threshold voltage shift and the radiation dose for all values of the gate bias. Furthermore, a power-law relationship between the radiation sensitivity and the gate bias during the irradiation was revealed...
November 2, 2017: Applied Radiation and Isotopes
Ahmed A Nigm, Mohamed A S Youssef, Fatema M Abdelwahab
An exploration method has been developed to understand the relation between the radiometric measurements and the subsurface petroleum accumulations, where subtle anomalous patterns of radiation flux are detected over subsurface hydrocarbon basins. This technique is mainly based on utilizing the aerial gamma-ray spectral data in the prospecting for petroleum in stratigraphic and structural traps. Al-Laqitah area, Central Eastern Desert, Egypt, was selected to apply this method on its recorded aerial gamma-ray spectrometric survey data...
November 1, 2017: Applied Radiation and Isotopes
Abubakar Sadiq Aliyu, Yahaya Musa, M S Liman, Habu T Abba, Mohammed S Chaanda, Nnamani C Ngene, N N Garba
The Keffi area hosts abundant pegmatite bodies as a result of the surrounding granitic intrusions. Keffi is part of areas that are geologically classified as North Central Basement Complex. Data on the mineralogy and mineralogical zonation of the Keffi pegmatite are scanty. Hence the need to understand the geology and mineralogical zonation of Keffi pegmatites especially at different depth profiles is relevant as a study of the elemental composition of the pegmatite is essential for the estimation of its economic viability...
November 1, 2017: Applied Radiation and Isotopes
B E Zimmerman
A new decay data evaluation for the positron emitting radionuclide (124)I has been performed using the Decay Data Evaluation Project (DDEP) methodology. New recommended values for the half-life, γ-ray emission probabilities, β(+) branching ratios, and other relevant nuclear and atomic data are provided. This paper provides a summary of the evaluation; the complete set of recommended data tables and detailed evaluator comments are available at the DDEP website.
October 31, 2017: Applied Radiation and Isotopes
S Pierre, B Sabot, P Cassette, J Liang, S Courte, L Ferreux, G Ratel
Two main non-destructive techniques can be used to measure standard (222)Rn gas ampoules: well-type ionization chambers and gamma-ray spectrometry, the former being used in the Système International de Référence (SIR) for international comparison purposes. The reliability of these techniques requires that the variability of the flame-sealed gas glass ampoules used have a negligible influence on the detector response. This variability is studied in this work by considering three parameters: the volume of the ampoule, the position of the sealing point and the thickness of the glass...
October 31, 2017: Applied Radiation and Isotopes
M Loidl, M Rodrigues, R Mariam
The ratios of the electron capture probabilities PK, PL and PM of (55)Fe have been measured with a metallic magnetic calorimeter, a specific type of cryogenic detector. The (55)Fe source was enclosed in the detector absorber, whose dimensions were chosen such that the detection efficiency for Mn K X-rays was larger than 99.99%. Since all electrons and photons emitted by the source are absorbed in the detector, the detection efficiency is virtually 100% for K, L and M captures. The energy threshold was low enough to allow for clear separation of the M captures (~ 80eV) from noise...
October 31, 2017: Applied Radiation and Isotopes
Wellington Marcos da Silva, Tiago Hilário Ferreira, Carlos Antônio de Morais, Alexandre Soares Leal, Edésia Martins Barros Sousa
Boron nitride nanotubes doped in situ with samarium (Sm-doped BNNTs) were synthesized at 1150°C under atmosphere of NH3/N2 gas mixture by thermal chemical vapor deposition (TCVD) using samarium oxide that is a product of the process separation of thorium and uranium tailings. The samarium in the BNNTs sample was activated by neutron capture, in a nuclear reactor, producing (152)Sm radioisotopes. The STEM-EELS spectrum and neutron activation show energies attributed to the samarium confirming the in situ doping process during BNNTs growth...
October 31, 2017: Applied Radiation and Isotopes
T K Venkatachalam, D H R Stimson, G K Pierens, R Bhalla, D C Reutens
[(18)F]Fluoroethyl tosylate was synthesized using an automated "Synthra" module using ethylene di-tosylate and [(18)F]fluoride/K222/K2CO3 in acetonitrile. [(18)F]Fluoroethyl tosylate was purified by semi-preparative HPLC followed by reformulation using a C18 Sep-Pak cartridge and eluted with DMF. Using this [(18)F]fluoroethyl tosylate, we attempted to alkylate protected tryptophan aiming to obtain the N-[(18)F]fluoroethyl-t-Boc-tryptophan methyl ester. Initial attempts resulted in the formation of the O-alkylated, rather than N-alkylated product...
October 28, 2017: Applied Radiation and Isotopes
M R Pahlavani, A Mostaar, J Nadali-Varkani
This paper investigates the use of a suitable gamma detector array to increase the detectably of explosives in a prompt-gammas neutron activation analysis (PGNAA) system. Monte Carlo simulations (MCNP-4C) were used for analyzing the system. It was found that the system's performance is enhanced by the use of four detectors: three of the are located on the same side as the neutron source and the fourth on the opposite side. Signature-based radiation-scanning, with nine signatures for each detector, is also discussed...
October 26, 2017: Applied Radiation and Isotopes
Seyoung Oh, Kyungrok Nam, Kyo Chul Lee, Mitra Ghergherehchi, Byungil Kim, Jung Young Kim, Ho Seung Song, Jong Seo Chai
A self-shielding device for the synthesis of radiopharmaceuticals was developed and fabricated in this study. Radiation exposure was minimized by the self-shielding of the kit, installation of the disposable kit in the auxiliary chamber while in a shielded state, and discharge of the kit into a radioactive waste container upon completion of the synthesis process. The developed self-shielding synthesis kit was tested by synthesizing 2-[(18)F]fluoro-2-deoxy-D-glucose ([(18)F]FDG) in order to verify its performance...
October 26, 2017: Applied Radiation and Isotopes
B Caro Marroyo, A Martín Sánchez, M Jurado Vargas, E García-Toraño, M Roteta
Gamma-ray emission probabilities for (243)Am were published in 1996. Three new gamma transitions were then found: 46.84, 98.36 and 102.02keV. In the last evaluation by the Decay Data Evaluation Project, the emission probabilities of 46.84 and 102.02keV transitions were not included. Alpha-gamma coincidence measurements have been now used to check and revise the values for these two transitions and their emission probabilities. The emissions of the 31.13, 43.53, 74.66, 86.71 and 141.89keV transitions were also studied...
October 20, 2017: Applied Radiation and Isotopes
Denis E Bergeron, Jeffrey T Cessna, Brian E Zimmerman
In nuclear medicine, (68)Ge is used to generate (68)Ga for imaging by positron emission tomography (PET) and sealed sources containing (68)Ge/(68)Ga in equilibrium have been adopted as long-lived calibration surrogates for the more common PET nuclide, (18)F. We prepared several (68)Ge sources for measurement on a NaI(Tl) well counter and a pressurized ionization chamber, following their decay for 110 weeks (≈ 2.8 half-lives). We determined values for the (68)Ge half-life of T1/2 = 271.14(15) d and T1/2 = 271...
October 20, 2017: Applied Radiation and Isotopes
M Rossi, C Balpardo, P Arenillas, G Cerutti, M C Ferrari
A 4πγ integral counting system with a NaI(Tl) well-type detector and a digital interface to acquire measurement data was implemented at LMR-CNEA. The detection efficiency as a function of the energy was computed by Monte Carlo simulations and the total efficiencies for ampoules and point sources were calculated considering all the decay branches. A computer code was developed to analyse data. This program reads the files generated by the digitizer module, corrects for dead time and calculates source activities and their uncertainties...
October 19, 2017: Applied Radiation and Isotopes
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