Abstract CsSnBr₃ nanocrystals are better than other lead-free perovskites because of their ease and low-cost synthesis, long-term function, and good stability. It is a suitable selection for use in tandem photodetectors. In this study, using the density functional theory, in the first stage, the elastic and electronic properties were calculated. Next, using the calculated quantities, the product of mobility-lifetime (µτ) of the charge carriers of CsSnBr₃ was calculated. According to the results obtained, both of the electron and the hole have the lifetime-mobility product of an order 10^-3 (V / cm²). The main reason for this can be attributed to the small effective mass of the charge carriers. However, this product has been reported for commercial detectors such as CdTe and CZT for electrons was of an order 10^-3-10^-2 and for holes in of an order 10^-4-10^-5. Therefore, due to the same of the product µτ in the CsSnBr₃ crystal, the final pulse will be the sum of both charge carriers. As a result, the CsSnBr₃ structure can show better potential for use in X-ray and gamma detectors.

Abstract In this paper, the polarized structure functions of  and nuclei have been computed in the second order of the Feynman diagram with and without considering SU(3) symmetry in spin dependence for the partonic distribution of nucleons. For this purpose and at first, the polarized structure functions of the nucleons in nuclei are obtained, using Jacobi polynomials. In this regard, two different and prevalent phenomenological models are used to obtain the required polarized partition distributions. Finally, in deriving the nuclear structure functions, effective nuclear corrections are also imposed. The results show that most of the plots for polarized nuclear longitudinal structure functions, resulted from the used phenomenological model whereas symmetry breaking is taken into account, are more compatible with the available experimental data, there is no considerable difference between the data compatibility with curves of both models for polarized nuclear transverse structure functions.
 

Abstract Due to the limited uranium reserves, the abundance of thorium compared to it, not being used in nuclear proliferation, and other advantages of thorium fuels over uranium fuels, the development of the thorium fuel cycle in various countries, including Iran, is considered. In this research, the separation and recovery processes of thorium from a real acidic leach liquor solution with a concentration of 500 mg/L thorium on a laboratory scale to produce thorium oxide precipitate were evaluated. The operating parameters affecting the extraction, stripping, and chemical precipitation processes of thorium include the type of extractant (acidic, basic, and neutral), the concentration of the extractant (0.05-1 M), aqueous phase acidity (0.032-6.92), equilibrium time (5-60 min), type and concentration of stripper (1-7 M) and precipitating agent were studied by the univariate method in each section. According to the experimental results, Di(2-ethylhexyl) phosphoric acid with a concentration of 1 M as extractant, aqueous phase acidity equal to 0.1, equilibrium time 60 min, sulfuric acid with a concentration of 5 M as a stripper, and ammonia as a precipitating agent were selected. Recovery of thorium from a real acidic leach liquor solution under obtained conditions resulted in the production of thorium oxide precipitate with a purity of 66%.

Abstract The load control of a nuclear reactor is important due to the nonlinear nature of its dynamics and the dependence of some parameters on the output power. the Proportional-Integral-Derivative controller (PID) is commonly regarded as an easy choice for reliable control. In this research, the relative neutron density in the point kinetics model of a Pressurized Water Reactor (PWR) is controlled by an optimized PID with the meta-heuristic Differential Evolution (DE) algorithm. The Integral of Time-Absolute Error (ITAE) performance index has been used for optimization with this algorithm. The simulation results show that the optimized control system with the DE algorithm has the appropriate efficiency and accuracy in response to power demand.

Abstract In a polywell reactor, it is critical to have a stable and energetic virtual cathode that is necessary to accelerate ions and create fusion interactions. Increasing the confinement time of virtual cathode electrons is of critical importance in the performance of polywell reactors. In this paper, COMSOL Multiphysics software was used to perform a three-dimensional numerical simulation in order to investigate the impacts of effective variables of a polywell on the virtual cathode. The findings indicated that the confinement time depends on the distance between the coils, coil radius, coil current, and the kinetic energy of the injected electrons. In addition, by using the simulation results, the dependence of the mentioned parameters on the confinement time is obtained, and then a mathematical model was developed.

Abstract Detecting the charge particles at Giga hertz rate is one of the applications of UFSD (Ultra-Fast Silicon Detectors). The UFSD test in front of the proton beam to count the beam particles and use it for a more precise Dose Delivery System for the treatment of the cancerous tumor by charge particles can become an effective step for the development of cancer treatment. In fact, this assessment is a prerequisite and guarantees the use of these detectors in the dose delivery system. In this regard, the best method for time measurement, which was CFD, was chosen. MATLAB software was used to measure and analyze the UFSD output signals. The results of the 50-μm-thick UFSD test and the various geometries that we performed in several different experiments at the CNAO Cancer Treatment Center in Italy, as well as the data obtained at the laboratory of CERN accelerator in Germany, were analyzed by the CFD method. The results of many different runs of programs in MATLAB for many registered signals show: 1- These sensors are reliable to count the proton particles in Giga hertz rate. 2-The CFD devices could be used to record the UFSD output signals. Therefore, they can be used in the correction of the dose delivery system as a counter for the proton number of the proton beam.

Abstract In order to modeling the gas behavior inside the rotor of a gas centrifuge, a powerful tool is needed to overcome the computational constraints of gas inside the centrifuge along with the ability to apply all drives at the all flow regimes. Due to the suitability of the DSMC method for all flow regimes formed inside the centrifuge, in this paper, the DSMC method is used to analyze the separation performance of a centrifuge in axisymmetric coordinates. For this purpose, using a multi-scale CFD-MD method, first the momentum accommodation coefficients required to use the Cercignani-Lampis-Lord boundary condition are extracted and then, based on that, the behavior of the gas inside a centrifuge machine is investigated using the DSMC method and the amount of separation power is determined. Based on the comparison of the simulation results with the experimental test results, it was shown that using the proposed hybrid method to determine the amount of momentum accommodation coefficients used in the CLL boundary condition of the DSMC method, can increase the accuracy of determining the amount of separation power of the machine up to 8%.

Abstract In this study, an effective and efficient separation method for separating praseodymium from cerium was designed, optimized, and successfully implemented. In this method, a special adsorbent for lanthanides (Ln-resin with dimensions of 100 to 150 microns) was used. A peristaltic pump and column with different dimensions (15 to 45 cm) were used to design the desired method. Systematic studies were performed to determine the eluent concentration of nitric acid (from 0.1 to 1 M). The oxidizing properties of cerium were exploited to differentiate the chemical behavior of these two lanthanides. NaBrO₃ was used as an oxidizer. Because in the continuation of this research, the target material of enriched cerium will be used, it is necessary to recover cerium as well. Ascorbic acid was used for the reduction of cerium. After changing the oxidation number of cerium, by changing the concentration of nitric acid, it is easily possible to wash the praseodymium and cerium separately and in high resolution using the commonly available acids and low column pressures with an efficiency of over 99%. This method was successfully used to separate praseodymium-143 from irradiated cerium in the reactor, and also to separate ¹⁴³Pr from the fission-produced lanthanides, the results of which will be presented in another report.

Abstract Foot and Mouth Disease Virus (FMDV) can cause a lot of economic losses in livestock. In this research FMDV subtype A-IRAN-05 was used. FMDV was multiplied on BHK21 cells and irradiated by electron beam (10, 20, 25, 30, 35, 40, 45, 50 kGy), then the dose/response curve was drawn by Origin software. D₁₀ value and optimum dose for virus inactivation according to the dose/ response curve and the results of the safety test and Complement Fixation test for the evaluation of antigenic characteristics were obtained at 8.33 and 55 kGy, respectively. Then irradiated vaccine and conventional vaccine were formulated with Aluminum Hydroxide gel and Saponin and used for injection on the guinea pig. The neutralizing antibody titration and splenic lymphocyte proliferation assay were shown a significant increase in humeral and cellular immunity induction in the irradiated vaccine and conventional vaccine to the negative control group (P<0.05). Also, the protective doses of irradiated and conventional vaccines were obtained at 6.28 and 6.13, respectively. It indicated the protective effect of both of the vaccines on a guinea pig.

Abstract In this article, the corrosion behavior of stainless steel (SS304) and carbon steel (St37) has been studied using immersion and potentiodynamic polarization methods in the presence of Shewanella RCRI7 bacteria. The results show that the corrosion behavior of SS304 and St37 is affected by passivation and biofilm formation. Based on the results of the immersion test, the corrosion behavior of SS304 has been much affected by passivation and the alloying elements (Cr, Ni, Mn, and Mo) so that the corrosion rate of SS304 decreased by 30% in presence of Shewanella RCRI7 bacteria at the first and fourth day of immersion. The corrosion rate in St37 has been decreased by 38% and 79% on the first and fourth day of immersion respectively, which indicates the impact of the biofilm on corrosion behavior. Potentiodynamic polarization tests show that cathodic reactions are affected by Shewanella RCRI7 bacteria and consequently the corrosion potential (E_corr) is shifted to more negative potentials (from
-360mV to -560mV for SS304 and from -610mV to -690mV for St37).

Abstract Austenitic stainless steels can withstand acidic environments relatively well. The sulfuric acid used in the process lines and the relatively high temperatures of the liquid (60oC) can cause general corrosion and pitting of the tank, which may eventually cause sudden failure. In order to reduce corrosion rates and prevent tank thickness from decreasing, it is imperative that appropriate coating systems be employed, since materials and the construction of new tanks are extremely expensive. In this study, stainless steel samples were coated with ceramic polymer-reinforced polymer coatings, graphite primers, glass liners, fluoroethylene chlorinated ethylene chloride, and fiber-reinforced vinyl esters. In order to evaluate and analyze the applied coatings, test methods such as holiday detection, hardness, adhesion strength, salt spraying, and electrochemical impedance spectroscopy were used. As a result of excellent adhesion to substrates regardless of sulfuric acid or chlorine exposure, glass linings are not just anticorrosive but also highly durable.

Abstract In this paper, the plasma of a 2.45 GHz permanent magnet miniature ECR ion source has been simulated and discussed. The source with a cylindrical plasma chamber of 50 mm in radius, 50 mm in length, and a maximum input power of 1kW generates a 10 mA, 50 kV proton beam. Considering the long wavelength of the microwave generator (λ0 = 122.4 mm) and the miniature size of the plasma chamber, an alumina window with a relative permittivity of 9 is hired at the entrance of the plasma chamber. Microwave power is injected into the chamber through the window. Microwave power transfer and coupling to the miniaturized plasma chamber of the ion source is the focus of this study. In this way, the strength of the magnetic field, microwave electric field, and spatial and temporal variations of the essential parameters like the density of the microwave power absorption, the Upper Hybrid Resonance (UHR) layer, density, and temperature of the plasma at the starting time of the microwave injection to the ion source chamber are investigated.

Abstract In this work, an argon microwave plasma with a frequency of 2.45 GHz at low pressure is experimentally demonstrated. Then, the characteristics of the formed plasma (temperature and density of electrons) in the presence and without the presence of a magnetic field are calculated and compared by optical emission spectroscopy. Permanent magnets are used to confine the plasma and supply the magnetic field in the electron cyclotron resonance mechanism. With the help of simulation, the proper arrangement of the magnets to produce the desired magnetic field is obtained. Then, using the relevant physical models, the temperature and density of the electrons are calculated. The results show that the magnetic field has a significant effect on the plasma characteristics and causes about 125% increase in temperature and 200% increase in electron density. It is also shown that, as expected, as the pressure decreases, the temperature of the electrons increases and their density decreases. This confirms the accuracy of the experiment and the obtained results

Abstract One of the essential systems for the upgrade of Damavand Tokamak is the automatic control of the vacuum vessel pressure profile. This research performs the identification, modeling, and control of the vacuum chamber pressure in Damavand Tokamak. As a first step, the experimental structure is designed and implemented for the application of an identification signal and for the collection of data from the vacuum vessel pressure. Following the creation of the base vacuum, the input voltage to the piezoelectric is changed and applied. At the same time, both the vacuum vessel pressure and applied voltage are measured. Using experimental data, several linear models are identified for control. Then, considering the practical limitations of the control signal (25<Vp<65), Ziegler-Nichols-based PID and predictive controllers are designed and simulated. Also, their performance results were compared and evaluated based on compensating for the system’s inherent delay, disturbance rejection, and reference model following. The simulation results show the performance of controllers.

Abstract In this research, the uranium recovery from Zagros region phosphate ore by calcination and acid extraction technology has been investigated. Also, the effect of different parameters on calcination and dissolution of uranium was investigated. The results showed that calcination temperature and calcination time as calcination factors; Also, leaching temperature, dissolution time, ore particle size, acid concentration, and liquid-to-solid ratio are important factors in uranium recovery from ore. Optimum operating parameters were established as follows: calcination temperature: 900 °C, calcination time: 2h; leaching temperature: 80 °C, leaching time: 4h, particle size: smaller than 100 microns, the concentration of sulfuric acid: 4M and liquid to the solid ratio: 3/1 mL/g. Under these conditions, uranium extraction efficiency from phosphate ore of the Zagros region was 84%.

Abstract This research investigates the transfer factor in the soil to plant (as one of the important parameters in safety analysis calculations and determining the amount of radiation of people) of strontium ion (a conventional radionuclide in pollution caused by nuclear accidents) to two plant samples including radish (Raphanus sativus var. sativus) and watercress (Lepidium sativum) as highly consumed plants in the food chain grown in the southern soil of Tehran. In this research, experiments were carried out in pots with a diameter of 15.5 cm and a height of 15.7 cm. These pots contained 2 kg of soil mixed with compost under the natural sunlight conditions of Tehran. In order to investigate the effect of strontium ion concentration on the transfer factor, the desired soil was first mixed with compost at a ratio of 3:1 and, using strontium nitrate salt solution in four different concentrations (50-200-500-1000 mg/kg) was infected. Pots were irrigated weekly with a specific volume of water at two different acidity levels (pH = 5 and 6) to investigate the effect of pH on the transfer factor. Also, the concentration of strontium ions in two tissues of the leaf and root of radish and watercress was done. This was examined to determine the accumulation of strontium ions in each of the tissues and their influence on the transfer factor. The results showed that with the increase in soil strontium concentration, the amount of adsorption of this element in both plants increases and the transfer factor decreases. Also, the plant had more adsorption in the soil with lower pH and a higher transfer factor was reported. The comparison of transfer factor and strontium adsorbed between the two plants also showed that radish adsorbed more strontium than watercress and had more transfer factor. Also, using an experimental method, the distribution coefficient, which is a crucial and practical parameter in pollutant transfer modeling and pollution risk assessment in soil and water resources, was determined by using the transfer factor from soil to plant. In this research, the possibility of decontamination of strontium from the soil by applying radish was investigated. The results showed that this plant could be used as a purifier to purify soils contaminated with strontium.

Abstract Carbon-12 ion beams in the energy range of 100-450 MeV/u have excellent conditions for radiation-resistant and deep-seated tumors. At energies above 400 MeV/u, radiation is significantly affected by nuclear fragmentation processes of increasing depth. In this project, using the Geant4 toolkit, three physical models of Binary Intranuclear Cascade (BIC), Lige Intranuclear Cascade (INCL), and Quantum Molecular Dynamics (QMD) for heavy particles are defined in this toolkit. By examining the QMD model available in the Geant4 toolkit, the effects of heavy particles because of fragmentation of the nucleus by calculating the abundance of nuclei produced with an atomic number in the range 5>Z>1 (H, He, Li, Be and B particles) at different depths of the water phantom before and after the Bragg peak and the angular distribution of these particles have been investigated by this model. The particle abundance graph shows that particle production decreases with an increasing atomic number. H and He particles are the most abundant and their range is much broader than the range of primary carbon ions. Also, according to the angular distribution diagram, H and He particles have shown a much wider distribution. This is because they have the highest dose of deposition in the area outside the treatment field. Also, with increasing atomic numbers, the angular distribution decreases.

Abstract One of the key parameters of neutron diffusing media is the thermal neutron diffusion length. The popular calculational method is founded on utilizing MCNP code and curve fitting of a mathematical function to the neutron flux distribution in the media. In this investigation, a novel method based on the PTRAC card is proposed. The thermal neutron diffusion length parameter for light and water is calculated based on the above methods. The results are compared with the reported values and significant agreement is seen. The advantage of the above method is its independence from curve fitting to calculate the neutron flux distribution. In addition, in the curve fitting method, it is assumed that there is enough distance from the source location. This affects the error of the results because the neutron flux distribution function is correct everywhere except at the neutron source location. In the present investigation, the correctness of the proposed method in light water media is evaluated numerically.

Abstract Antibody-based radiopharmaceuticals are of increasing interest today in cancer imaging and radiotherapy. The cetuximab monoclonal antibody binds to the epidermal growth factor receptor (EGFR) and thus provides therapeutic and diagnostic protocols against this receptor. Following purification and conjugation with freshly prepared DOTA-NHS, the cetuximab antibody was labeled with lutetium 177 and samarium chloride-153. Labeling efficiency and in vitro stability were measured using thin-layer chromatography. Cellular tests were performed to determine radioimmunoactivity in cancer cells. The results showed that the labeling efficiencies of 177Lu-DOTA-cetuximab and 153Sm-DOTA-cetuximab were more than 97±1% and 96±2%, respectively. Also, the in vitro stability of the labeled products in fresh human serum after 96 hours was 83±  22% and 78%, respectively. Immunoreactivity was 91% for 177Lu-DOTA-cetuximab and 66±1% for 153Sm-DOTA-cetuximab. With different intensities based on time and beta energy, both products inhibited the growth of HT29 colon cancer cells. The results showed that the immunoconjugate complexes of 177Lu-DOTA-cetuximab and 153Sm-DOTA-cetuximab can be considered a novel radiopharmaceutical for cancer radioimmunotherapy.

Abstract In this work, a continuous wave fast axial flow RF CO2 laser has been constructed, which is pumped by a 1 kW RF generator with a 13.56 MHz frequency. In order to optimize the laser performance, the diameter of the discharge tube, electrodes width, the ratio of the width of the electrode to the tube perimeter, gas ratio, and total pressure of the gas mixture was changed over a wide range for a constant electrode length of 10 cm and then the laser output power and efficiency were measured. The maximum output power of 63.5 W, implying% a 6.3 electric efficiency, was obtained for 26 mm discharge tube diameter, electrode width to discharge tube perimeter ratio of 0.6, gas mixture, and 90 mbar total pressure..