Radiation Applications
Mehrdad Shamsinasab; Mansour Asgari; Mahdi Eshghi
Abstract
Nuclear-pumped lasers (NPL) are lasers that excite the active laser environment caused by nuclear reaction. Such lasers need ionizing radiation shielding for mixed neutron and gamma fields. In this work, a shielding system for NPL was designed which using 10B(n,α)7Li. In this simulation, we have ...
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Nuclear-pumped lasers (NPL) are lasers that excite the active laser environment caused by nuclear reaction. Such lasers need ionizing radiation shielding for mixed neutron and gamma fields. In this work, a shielding system for NPL was designed which using 10B(n,α)7Li. In this simulation, we have used MCNPX 2.6.0 Monte Carlo code and the thermal neutron flux as 1×1016 n.cm-2.s-1 for excitation reaction. Such a large neutron flux can be obtained from a reactor source or a heavy ion accelerator. For this work, 10B fuel is covered on the surface of a rectangular cube aluminum shell by using the Monte Carlo method. In the design of the shielding, combinations with different materials have been used with various arrangements in three layers. According to the simulation, the arrangement of Fe2-B-BPE-Pb is a suitable protection compound for such lasers.
Mahdi Eshghi; Sasan Soudi; Sameer M. Khadir
Abstract
The scattering problems, in the presence of an external potential field, have become highly interesting topics in relativistic and non-relativistic quantum mechanics. It is well known that the scattering of a relativistic particle in the field of a potential can be treated exactly by finding the continuum ...
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The scattering problems, in the presence of an external potential field, have become highly interesting topics in relativistic and non-relativistic quantum mechanics. It is well known that the scattering of a relativistic particle in the field of a potential can be treated exactly by finding the continuum solutions of the Dirac equation. In this research, we obtain the exact solution to the Dirac equation with the Pöschl-Teller double ring-shaped Coulomb (PTDRSC) potential for any spin-orbit quantum number k. The relativistic scattering amplitude for spin 1/2 particles in the field of this potential has been studied. The wave functions are being expressed in terms of the hyper-geometric series of the continuous states on the k/2π scale. In addition, a formula for the phase shifts has also been found. In the nonrelativistic limits, our solution to the Dirac particle converges to that of the Schrödinger one. At the high temperature, the partition function is being calculated in order to study the behavior of some thermodynamic properties.
Mahdi Eshghi
Abstract
The buildup factor is becoming a required parameter for exposure and energy absorption in the area of radiation physics for shielding, dosimetry, health physics and medical physics. In this research, photon buildup for dysprosium doped lithium magnesium borate glasses system has been investigated. Photon ...
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The buildup factor is becoming a required parameter for exposure and energy absorption in the area of radiation physics for shielding, dosimetry, health physics and medical physics. In this research, photon buildup for dysprosium doped lithium magnesium borate glasses system has been investigated. Photon energy absorption buildup factors and photon exposure buildup factors were computed for the chosen glasses using the five-parameter geometric progression fitting method in energy range of 0.015 MeV to 15 MeV. Also, effective and equivalent atomic numbers were calculated for these compositions and discussed for possible implementation in radiation dosimetry.
Nahid Sohebi; Mahdi Eshghi; Majid Hamzavi; Mohsen Bigdeli
Abstract
In the present work, the eigenvalue and eigenvector has been obtained by the Bohr Hamiltonian for even-even nuclei. The competition between γ-stable and γ-rigid collective motions has been created in the presence of the rigidity parameter. The β-part ...
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In the present work, the eigenvalue and eigenvector has been obtained by the Bohr Hamiltonian for even-even nuclei. The competition between γ-stable and γ-rigid collective motions has been created in the presence of the rigidity parameter. The β-part of the collective potential has been chosen to be equal to the generalized Hulthen potential, while the γ-angular part of the problem is associated with Ring-shaped potential around the γ=π/6 and the Harmonic oscillation around the γ=0. In both cases, the effect of rigidity and free parameters on energy spectrum of Os-180, Dy-162, Gd-160, Ru-100, Pd-114, and Xe-124 nuclei have been investigated. Also, the rates of B(E2) transition have been calculated and compared with experimental data. This model has an appropriate description of energy spectra for the mentioned nuclei.
