مجله علوم و فنون هسته ای
سال چهل و یکم شماره 3 (پیاپی 93، پاییز 1399)

In this paper, the spectral statistics of prolatedeformed nuclei are investigated by using random matrix theory. To this aim, we used both available experimental data and also the energy levels of ground, beta, and gamma bands of 51 deformed even-even nuclei, which are determined via partial SU(3) dynamical symmetry limit of interacting boson model. The results verified the ability of the considered models in the restoration of experimental data and also the displacement of beta and gamma energy bands. Also, the dependence of the statistical situation of energy levels is considered to the mass of nuclei, spins, half-lives of the ground state, bands of energy, and different configurations of excited bands of energies. The results suggested obvious differences in the spectral situation of the levels in different rotational bands and also different mass regions. Also, the displacement of levels and the lower energy of  state in comparison with level reduce the correlation of levels in spectral statistics.

Studying the dynamical behavior of various nucleus systems has become an interesting subject of research over recent years in nuclear physics. The Energy spectrum and magnitude of momentum of electric and magnetic multi-poles may describe the behavior of a nuclei collection under a special symmetry group. In this paper, solvable algebraic models by using the affine SU(1,1) Lie Algebra and proton, and neutron degrees of freedom in the framework of an  interacting-boson-fermion-fermion model(IBFFM) is suggested to determine the exact energy and eigenstate of the  transitional odd-odd mass nuclei. The main goal is to study the dynamical behavior of the nucleus in the transition state and then to investigate the special conditions that make this transition process possible. The positive parity low-lying energy states of the 60−66Cu isotopes within the proposed methods are investigated. The obtained results compare well with the available experimental data and IBFFM-1, which augments the reliability of the wave function and Hamiltonian obtained within the suggested IBFFM-2 model. The values of control parameters confirm the mixing of both vibrating and rotating structures in the 60−66Cu isotopes.

The Λ*‎ resonance has been studied and investigated both theoretically and experimentally for decades‎. ‎The purpose of this paper is to study the mass and width of Λ* resonance state theoretically by calculating the T-matrix using a generalized optical potential with a Yukawa-type separable potential‎. ‎In the current calculation, the formation of Λ* in the K-d → Λ*‎ + ‎n → (Σπ)0 + n reaction is studied and the results of the analysis are fitted to the experimental data of E-31 carried out at J-PARC accelerator which is related to the collision of negative kaon of 1GeV/c momentum with liquid deuteron and according to the best fit‎, ‎mass and width of this resonant state calculated as MΛ* =1419 ± 2.4 MeV/c2 and , ‎respectively.

The stimulated Raman scattering caused by beating of two counter-propagating lasers in magnetized plasma has been investigated. The input waves have a right circular polarization and the plasma is embedded in a uniform axial external magnetic field. Also, the difference in frequency of the input waves is more than twice that of the plasma frequency. Pandromotive force generated by the beat wave excites a plasma wave and scatter the beat wave in the plasma. The nonlinear current density due to the coupling of the plasma wave and the beat wave causes the amplitude of these waves to increase. By using the equation of motion of electrons as well as the wave equation, the dispersion relation of the scattered wave and the growth rate of instability have been obtained. It shows that the presence of the magnetic field increases the maximum growth rate. Also, the growth increases by increasing the external magnetic field, so that, the instability is exacerbated at the cutoff frequency. Also, the greater the difference in the frequency of the two waves of pumps, the more the growth rate.

The accuracy of each simulating beta-voltaic battery parameter is very important, especially in micro-batteries. The aim of this study is to improve the calculation of beta-battery parameters’ accuracy. For this purpose, at first, using the Monte Carlo N-Particle code (MCNPX), the energy accumulation distribution of the 63Ni beta particle spectrum inside a silicon semiconductor has been simulated. Then, the ATLAS C-Interpreter function in C ++ was defined, using one of the SILVACO code abilities (the parameter F.RADIATE BEAM statement). Finally, the device electric parameters have been obtained using ATLAS-SILVACO based on the location-dependent of MCNPX results. For validation, the calculations were performed for a battery sample made of 16 mm2 cross-section and 1 mCi activity of radioisotope 63Ni as a source, and finally, the results were compared with one experimental result and two analytical methods. The calculations repeated for the other sample with 100 mCi activity and 1 cm2 of geometry, and compared its results with an analytical method results. The results showed that the simulation of micro-battery characteristics by the MCNPX-SILVACO hybrid code using three-dimensional electron-hole pairs’ distribution in semiconductor and the full spectrum of beta particles creates a significant increase in the accuracy of the computation, and provides a good capability to optimize the design of the battery.

These days, the use of Rhenium 186 and 188 radionuclides in the production of various radiopharmaceuticals has grown considerably. These two radionuclides have good features such as emitting beta particles with appropriate range and energy, and gamma rays for imaging and evaluating biological distribution in cancer treatment. Regarding the energy and range of these radionuclides, Rhenium 186 with small range is suitable for treating small tumors; and Rhenium 188 with greater range is appropriate to destroy large tumors. In this study, the simultaneous production of these two radionuclides by natural rhenium irradiation for the production of a combined radiopharmaceutical, to treat tumors with various sizes has been investigated. For the purpose of this study, the irradiation of 1 mg of natural rhenium in a neutron flux of 3×1013 cm-2s-1 for 7 days was evaluated and the activity of the main products was calculated. Since the presence of impurities delivers an unwanted and excess dose to the patient, the presence and activity level of these radionuclides have also been studied. The results of the study showed that by the irradiation of natural rhenium, Rhenium 186 and 188 radionuclides can be produced simultaneously with the appropriate activity level for using the combination of both radionuclides. Also, theoretical calculations showed that the amount of produced impurities compared to the original products is negligible.

This investigation is a computational analysis of a kind of radiation effect on electronic devices, known as the single event upset (SEU) with the Geant4 toolkit. Accordingly, the results are compared with the similar experimental work and a simulation study which is performed by CRÈME-MC Monte Carlo simulation code. Single event upsets are the most common events which abruptly change the logic state of the device (1 to 0 or vice versa) and cause a disturbance in their performance. In the simulations, low energy protons (< 10 MeV)-induced SEU cross sections in a 65 nm CMOS SRAM were calculated and various particle effectivenesses and physical mechanisms inducing upsets were studied. The analysis of the results showed that most of the upsets occur due to incident protons with energies of less than 1 MeV under the mechanism of direct ionization. This is due to the fact that protons entering the sensitive volume have the maximum stopping power. This study also revealed that for protons with energies between 2 and 10 MeV, recoiled silicon atoms have a dominant role in SEU while other particles produced in preceding layers have a negligible effect compared to the recoiled silicon produced inside the sensitive volume.

Acceleration of high energy charged particles is one of the most important applications of high-power lasers interaction with plasma. Using targets with densities close to critical densities, because of better laser-plasma coupling, the transferred energy from the laser to plasma will be increased. Today, due to the construction of foam-structured targets, with a density close to critical density, it is possible to use such targets in order to study more about the acceleration process of particles with densities close to the critical density. In this paper, using particle simulation in a cell, a realistic form of foam structure of laser interaction with targets has been studied in more detail. The optimal state for porous foam in terms of dimensions and distances between holes is proposed based on the maximum energy of the protons produced after the laser pulse is completed and it is found out that for a foam with a density of 3.6 critical density and 16-micrometer length, the existence of holes with 0.5-micrometer radius and 1.5-micrometers for the distance between the centers can produce protons with 40 MeV energy but if the holes are not in proper conditions, protons’ maximum energy will be decreased about 20 percent relative to the condition without porous foam.

In this study, we have considered a two-dimensional triangular lattice photonic crystal composed of liquid crystal infiltrated air holes in Si background. Then, we investigate the band structure, equifrequency contours, and the field intensity distribution for different values of structural parameter; using plane wave expansion and finite-difference time-domain methods. In the following, it is found that for the optimum values of geometrical parameters the structure represents a similar behavior with a system with a negative refractive index for a relatively wide frequency range. The negative refractive index causes that in a specified frequency width, the image of a light source appears perfectly on another side of the designed photonic crystal. In the end, the effect of an externally applied voltage on liquid crystals is studied. Our simulations reveal that applying the external electric filed changes the refractive index of structure and can be used for tuning the negative refractive effect.

The Electromagnetic Isotopes Separator (EMIS) installed in Karaj, has the capability to separate isotopes in a wide range of elements. Zirconium is successfully separated using this method for the first time in Iran. Zirconium element has five stable isotopes, 90Zr, 91Zr, 92Zr, 94Zr, and 96Zr, and the natural abundance of 90Zr is 51.45%. The 90Zr isotope is used to produce radioisotope 90Nb via 90Zr(p, n) 90Nb  that has a high potential for antibody labeling application in PET as a radionuclide. Copper pockets and graphite front plate were designed and fabricated for separating and collecting of Zr isotopes. After choosing the appropriate composition for the initial material, the electrical parameters of the ion source and electromagnet were determined. The mass spectra of Zirconium isotopes were recorded. Deposited 90Zr isotopes were first extracted from the copper pocket and then purified by electrodeposition and purification methods. The formation of 90ZrO2 was confirmed by X-ray diffraction (XRD). Chemical purity and isotope purification of 90Zr isotope were 99.22% and 99.85%, which measured by TIMS and PIXE method analysis, respectively.

Following the Fukushima Daiichi accident, the simulation of accidents related to the Spent Fuel Pool (SFP) became more important due to the high content of long-lived radionuclides, and lack of the protection by the pressure vessel despite its low decay heat. Therefore, the loss-of-cooling accident in the SFP of the Bushehr NPP was first simulated in this paper. The RELAP5 (as the Best Estimate code) and MELCOR (as a Severe Accident code) codes were used for simulation of the loss-of-cooling accident. The decay heat power calculation was performed by the ORIGEN code. The nodalization of SFP was done by using the Final Safety Analysis Report (FSAR) of Bushehr NPP. Different phenomena such as increasing water temperature in the pool, water boiling and decreasing of pool water level, spent fuel uncovering, increasing fuel temperature and the onset of fuel melting, hydrogen production, and release of radio-nuclides were observed and investigated. The steady-state results were validated by Bushehr NPP operating data. Verification of transient and accident results was performed by code-to-code (RELAP5 & MELCOR) comparison approach and Bushehr NPP data, the results showed that a good agreement together.

Today, humans are surrounded by countless sources of gamma radiation, and therefore, radiation shielding has always been a big concern. Different methods which are generally based on the use of lead-based metal and heavy shielding materials have been developed to absorb this radiation in recent years. Lead is not a good shield due to its high cost, toxicity and weight. The purpose of this study is to produce lightweight composites with the highest protective strength based on SBR rubber. Therefore, in order to produce anti-radiation rubber, various formulations were used. For this purpose, montmorillonite (MMT) Clay and various metal oxides such as Iron Oxide (Fe2O3), Zink Oxide (ZnO), Molybdenum Oxide (MoO3), and Titanium Oxide (TiO2) were used as filler. Then, the shielding properties of the composites made with Europium (152Eu) radioactive source in the energy range of 122 to 964 keV were investigated. The shielding properties of the composites including linear attenuation coefficient, absorption rate, half-value layer (HVL), and tenth-value layer (TVL), and other properties of rubber composites were studied by different analysis including mechanical strength, hardness, TGA, SEM. Among the samples tested, the sample containing MoO3 and MMT was the best material for absorbing these rays with an absorption rate of about 99%.

The peptides radiolabeled with 177Lu are including a wide range of promising radiopharmaceuticals. The NCA form of 177Lu provides a high specific activity that is required in targeted receptor therapy in order to avoid saturation of the targeted receptors. In this study, the outstanding quality of NCA radionuclides especially in the case of 177Lu was evaluated by comparing with CA radionuclide for radiolabeling of DOTATATE peptide and. The NCA 177Lu and CA 177Lu were obtained by chromatography separation of irradiated 176Yb (enrichment: 96.4%) and irradiation of 176Lu (enrichment: 95%) respectively. Radiolabeling of DOTATE with CA and NCA 177Lu was carried out in the same conditions and time. Then, radiolabeling yield was calculated as a function of some parameters like the Ligand: metal ratio and stability of compound after production. The results showed the superiority of NCA 177Lu with respect to CA 177Lu. Not only the particle ratio showed the advantages of the NCA radionuclide, but also the long-term comparison over a period of 14 days revealed the inferior character of CA.177Lu with regard to the high requirements regarding the specific activity set by radio-immunotherapy.

This paper examined the behavior of confined 238UF6 gaseous ions in Paul’s quadrupole mass spectrometer under the influence of the field induced by the RF and DC potential applied to the end cap and ring electrodes and space charge potential, based on the solutions of Mathieu’s second-order linear differential equation. The results of calculation and simulation were compared in the absence and presence of space charge potential effects. The analytical and numerical results demonstrated the displacement of stability diagram of the confined 238UF6 gaseous ions in Paul's quadrupole trap due to the space charge potential. In addition, the space charge effect on the maximum density of the confined 238UF6 ions, the velocity distribution function of the confined ions and other statistical quantities were also calculated. The quadrupole ion trap forms the most important part of a mass spectrometer, and the mass spectrometer is widely used in the uranium enrichment industry.

Alkali fusion with NaOH is the most commonly used method for the extraction of zirconium from zircon sand. In the alkali fusion process, the acid leaching step has a great influence on the zirconium recovery and purity of the final product. In this study, the Grey-Taguchi method was utilized to find the optimum conditions of the acid leaching process. In order to apply this method, acid type, acid concentration, leaching temperature, and liquid/solid ratio were selected as control factors with responses of zirconium recovery and R=Si/Zr ratio. The results demonstrated that the optimum condition for acid leaching requires 4 mol/L sulfuric acid with a liquid/solid ratio of 20 at 60 °C. Zirconium recovery and Si/Zr ratio (R) under these optimum conditions were 92.73% and 0.0018, respectively. Also, the silica content in the acid leaching solution was 30.94 ppm. The results of this research suggest facile, low price, and proper method comparing to the carbochlorination method for recovery of zirconium from zircon mineral.

Nowadays, thermoluminescence is a known phenomenon that is observed in many solids (insulators and semiconductors). Given the various applications, it is necessary to acquire accurate relationships that correctly describe this phenomenon. Meanwhile, the thermal quenching effect is one of the effective factors. This effect, is observed with both increasing temperature and the probability of non-radiative recombination. Also, by increasing the heating rate, the maximum temperature and maximum intensity of the thermoluminescence glow curve are affected,in a way that the maximum temperature increases, and the maximum intensity decrease. In this study, the variation of the thermoluminescence glow curve of CaF2: Mn(TLD-400)dosimeter has been investigated for different heating rates. This way, after observing the thermal quenching effect for this dosimeter, the related parameters were determined as W=3eV and C =2.1×1027 through the fitting of experimental data with the associated theoretical equation. The obtained thermal quenching parameters can be used for fitting the experimental thermoluminescence glow curves to the theoretical models to determine the kinetic parameters.

As a step towards the development of liquid membrane technology for the recovery of thorium from dilute solutions, the article investigates transport behavior of Th(IV)‏ from a feed (solution) phase containing 0.0001M hydrochloric acid (HCl) into a recovery phase containing 1.5M sulfuric acid (H2SO4) in a continuous flow liquid membrane (CFLM) containing 0.2 M Di-(2-ethylhexyl) phosphoric acid (D2EHPA) as the ion carrier. The assessment of the transport process was performed by determining the kinetic parameters—mass transfer coefficient, and entrance and exit flow in and out of the chloroform membrane. The ability of the CFLM for thorium(IV) recovery from aqueous solutions was confirmed with transport experiments. In addition, transport experiments also show the extraction and back-extraction steps to proceed simultaneously and in a continuous fashion. The obtained results showed that with an increasing flow rate of the membrane and recovery phases the transport rate of thorium ions will increase, while feed flow rate had no significant effect on the transport of thorium(IV). At the flow rates higher than 300 mL min-1 for the recovery phase, the mass transfer resistance in this phase decreases to its lowest value. According to the kinetic studies, extraction of metal ions from the feed solution provides faster kinetics than their back extraction into the recovery aqueous phase.

Caspian Sea salmon (Salmo trutta caspius) is a valuable fish species in the Caspian Sea and its surrounding basin, which is considered as a suitable species in our country's fishing industry. Caspian salmon ovums and sperms were extracted from Caspian salmon. To perform gynogenesis, the sperms were irradiated with a gamma ray (60Co) at doses of 450, 600, 750, 900, and 1050 Gy. In the next stage, fertilization was performed by mixing the ovum and the irradiated sperm. To induce ploidy, a water bath with a temperature of 26-28 ˚C was established. The tail fins of different treatments were sampled and the DNA was extracted and its sex was determined using primers E1S1 and E2AS4 related to SDY gene. After salmon reached the appropriate weight, its sex was studied using classical histology. The results showed that in the 900 g group of fertilization, the survival larval was significantly higher than other gynogen groups (p < 0.05). Gender determination using molecular methods showed that in the treatment of female with a dose of 450 Gy, there is still one male determined. (1 sample out of 5 samples), this happened in a case that there was no male in other doses. But in all histological samples, there is no sign of male gonad. According to these results, it can be concluded that the gynogenesis of Caspian Sea salmon has been done successfully using this gamma irradiation method and a dose of 900 Gy is recommended as a suitable dose for using this method in this species.

In this paper, the structural, electronic, optical, and thermal properties of indium nitride in the pressure phases are investigated. The calculations are performed using the pseudopotential method in the framework of density functional theory and by using the quantum-espresso Package. In the calculations, the exchange-correlation terms of LDA, GGA, and PBE0 approximation are used. The results show that indium nitride retains its semiconducting properties under the pressure phase and has a static refractive index of 2.75. And the largest part in the valence band is related to the orbital s of the N atom and in the conduction band is to the orbitals of s and p of the In atom. The results of the optical properties show that the band structure approximation corresponds to the imaginary contribution of the dielectric function as well as the approximate equality of the bandgap to the optical bandgap. The results are consistent with other available data.

The electron accelerator located at Yazd is working with tap water as cooling. This equipment is made of carbon steel (A37). This steel, as a typical carbon steel, is very susceptible to corrosion destruction in uncontrolled condition. Using tap water as a coolant, has led to high corrosion and thus blocked water circulation paths. XRD and XRF analysis of corrosion products from different parts of accelerator showed that a large quantity of these sediments is composed of Iron Oxide. SEM images indicated that the sediments have a Tubculation morphology. Also, the ICP-OES results showed that in comparison with Yazd tap water, the chemistry of the cooling water circulating in the accelerator has been changed, consequently its hardness decreased by passing time. The results obtained from the Langelier parameter showed that the water exiting from the end of the cooling system is a little corrosive. Due to the color and morphology of corrosion products, the corrosion mechanism is a Tubculation type.