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This paper proposes a novel approach for generating high-resolution energy spectra using cost-effective Sodium iodide Thallium activated (NaI(Tl)) detectors. It employ a multi-output regression chain structure based on support vector regression (SVR) to map NaI(Tl) spectra to their corresponding HPGe spectra. The suggested framework utilizes a regression chain strategy to enhance regression models that lack support for multi-output regression. This involves initially employing one regressor for each energy channel of the HPGe spectrum. Subsequently, multiple regressors are integrated to forecast all energy channels of HPGe spectrum. Each regressor in the chain receives the entire NaI spectrum as input. Then, for each subsequent regressor, input is further augmented by concatenating the outputs of all preceding regressors in the chain. Despite being trained on a limited radioisotope library, the model exhibits exceptional performance across diverse measured test spectra containing multiple radioisotopes. Among the various kernel functions employed (linear, radial basis function (RBF), and polynomial), the RBF and polynomial kernels yielded superior performance compared to the linear kernel. By enabling HPGe spectrum prediction using NaI(Tl) detectors, this study highlights a significant advancement in radiation detection capabilities, addressing cost and operational considerations.

Polymer composites when reinforced with heavy metals in the form of micro/nano particles are efficient gamma- and X-ray shielding materials providing such advantageous features as cost-effectiveness, light-weight factor, flexibility, non-toxicity, conformability over conventional shields.

In this paper the influence of weight percentages and particle sizes of bismuth and tungsten contents of reinforced composites, i.e., bismuth/rubber (Bi/R) and tungsten/rubber (W/R) shields, in their photon absorption capabilities for photon energies, ranging from 40 to 350 keV, were investigated using both MCNPX simulations and measurements. The Bi/R and W/R polymer composites were prepared by mixing rubber with different weight percentages of bismuth and tungsten powders before exposing them to 152Eu gamma-rays. Then, the shielding efficiencies or photon transmission fractions, half-value layer (HVL) and tenth-value layer (TVL) of the samples were determined.

The simulation results confirmed that the particle size of the heavy element plays an important role in the shielding efficiency, especially at low photon energies. The decrease in the particle size of shielding material in each weight percentage improved the radiation shielding features. Therefore, the results supported the feasibility of nano-sized composite applications for shielding against low-energy photons, especially in diagnostic studies such as mammography.

At low photon energies, especially around 40 keV, a considerable decrease in photon flux was achieved by incorporating nano-sized heavy elements in a polymer matrix.

In this study, a Compton camera imaging system containing several scatterer layers made of Si and a LYSO detector as an absorber layer were designed and simulated using Geant4 code. At first, the efficiency of the system according to the number of scatterer layers was optimized using a gamma point source with various energies. After finding the best structure of the system which contains 10 layers of scatterer, two similar setup of Compton camera were placed perpendicularly to the proton beam around the phantom to take image of the position of the prompt gamma emission resulted from the nuclear interaction of the proton beam with the phantom. In order to imaging the gammas, information such as interaction positions and deposited energies in the scatterers and absorber were recorded by Geant4 code in a root file. Then, using a Compton camera reconstruction algorithm, production position profile of gammas was reconstructed in a MATLAB software. A Comparison of the gamma photon distribution and dose distribution showes that this Compton camera structure is able to measure the proton beam range with less than 7 mm error, which proves the capability of prompt gammas detection for verification of the proton beam range during proton therapy.

In this study, Trastuzumab was labeled with 177Lu, and its dosimetric calculation was performed considering the assessment of the absorbed dose in the organs of human body. 177Lu chloride was prepared after 7 days irradiation of enriched Lu2O3 in the Tehran Research Reactor at the thermal neutron flux of 4×1013 cm-2 s-1, and the specific activity of 70-80 GBq/mg. 177Lu-DOTA-Trastuzumab was obtained with an overall radiochemical purity of >98% under the optimized conditions. Biodistribution studies of the radioimmunoconjugate in normal rats were carried up to 168 h. Relative organ mass extrapolation method was used for calculation of the human absorbed dose. Because of the highest accumulation activity in reticuloendothelial system, liver and spleen have received the maximum dose of 0.95 and 0.89 mSv/MBq, respectively.

In this article, different types of cyclotron solid targets and their advantages and disadvantages are discussed and a new design is introduced for solid targets of IBA-Cyclone 30 cyclotrons for the first time. In this new targetry, the number and depth of the back grooves for coolant passage were changed. The target material was placed behind an aluminum drawer for bombardment. For this reason the new targetry was named drawer backings. Thus we were able to bombard powders of the target material. These backings have unique capabilities: metallic salts can be bombarded behind the drawer holders and chemical separation may be performed with higher yields and lower costs with respect to other methods. The bombardment may be repeated many times with the same backing. The drawer avoids the presence of contaminant nuclides in the final product.

In this work the design of a target converting high energy electrons to bremsstrahlung x-ray is described. The system has been optimized for different energy of the accelerated electron beam, using the EGS4 Monte-Carlo computer code. For this purpose the thickness of the layers in the target, including the main converter, cooling and lower layer (for the energy spectrum tuning), suitable to the desired and practical conditions have been obtained. In order to evaluate the calculated results, measurements have been carried out for the same geometry using the x-ray converter target, for 2MeV, 5MeV and 10 MeV electron beam. It is shown that the calculated data are in good agreement with the experimental results.