Isfahan University of Technology,
The Physics Society of IranIranian Journal of Physics Research1682-695720420210219Study of neutron-rich nuclei reaction using ImQMD modelStudy of neutron-rich nuclei reaction using ImQMD model569577164910.47176/ijpr.20.4.27311FAVZanganehDepartment of Physics, Golestan University, Gorgan, IranAIzadpanahDepartment of Physics, Golestan University, Gorgan, IranMAhmadiDepartment of Physics, Golestan University, Gorgan, IranJournal Article20161212In the present study, the fusion reactions induced by neutron-rich nuclei have been investigated using the improved quantum molecular-dynamics (ImQMD) model. First, the accuracy of the results was determined by using a set of parameters IQ3a for 16O+92Zr, 40Ca+46Ti and 16O+154Sm fusion excitation functions. The obtained results revealed that the measured fusion excitation function can be reasonably well reproduced. A comparison was also performed with the theoretical results based on the coupled-channel calculations. Then, the time evolution of densities for the 16O+59Co and 32S+92Zr reactions in which the target nuclei were neutron-rich were studied and the fusion cross sections were calculated dynamically. It was found that the fusion cross sections of these reactions at energies around the Coulomb barrier can be well reproduced by using the ImQMD modle.In the present study, the fusion reactions induced by neutron-rich nuclei have been investigated using the improved quantum molecular-dynamics (ImQMD) model. First, the accuracy of the results was determined by using a set of parameters IQ3a for 16O+92Zr, 40Ca+46Ti and 16O+154Sm fusion excitation functions. The obtained results revealed that the measured fusion excitation function can be reasonably well reproduced. A comparison was also performed with the theoretical results based on the coupled-channel calculations. Then, the time evolution of densities for the 16O+59Co and 32S+92Zr reactions in which the target nuclei were neutron-rich were studied and the fusion cross sections were calculated dynamically. It was found that the fusion cross sections of these reactions at energies around the Coulomb barrier can be well reproduced by using the ImQMD modle.Isfahan University of Technology,
The Physics Society of IranIranian Journal of Physics Research1682-695720420210219Study of the optical properties of Aluminum zigzag thin films
via transfer matrixStudy of the optical properties of Aluminum zigzag thin films
via transfer matrix579589165010.47176/ijpr.20.4.5121FAMGholizadeh ArashtiDepartment of Physics, Faculty of science,Yadegar-e-Imam Khomeini (RAH) Shahre Rey Branch, Islamic Azad University, Tehran, Iran0000-0001-7071-8227MFakharpourDepartment of Physics, Faculty of science, Maybod Branch, Islamic Azad University, Maybod, IranJournal Article20191126The transfer matrix method adopted to solve the linearly polarized light propagation problem in order to study the occurrence of absorption transitions for Aluminum zigzag thin films. For different incident light, azimuthal angles, arms number and lengths, the optical results showed that the intensity of absorption peak of s-polarization remains constant as the incident light angle increases, while the intensity of absorption peaks for p-polarization increases. According to the variations of spectra for different azimuthal angles, the results of p-polarization are opposite to s polarization. Also, changing the number of arms from two to three, three to four and four to five, shift the peaks of absorption spectrum towards longer (red shift), shorter (blue shift) and longer wavelengths (red shift), respectively. This behavior can be observed for zigzag nano-structure with different arm lengths.The transfer matrix method adopted to solve the linearly polarized light propagation problem in order to study the occurrence of absorption transitions for Aluminum zigzag thin films. For different incident light, azimuthal angles, arms number and lengths, the optical results showed that the intensity of absorption peak of s-polarization remains constant as the incident light angle increases, while the intensity of absorption peaks for p-polarization increases. According to the variations of spectra for different azimuthal angles, the results of p-polarization are opposite to s polarization. Also, changing the number of arms from two to three, three to four and four to five, shift the peaks of absorption spectrum towards longer (red shift), shorter (blue shift) and longer wavelengths (red shift), respectively. This behavior can be observed for zigzag nano-structure with different arm lengths.Isfahan University of Technology,
The Physics Society of IranIranian Journal of Physics Research1682-695720420210219Visible and near infrared upconversion emission from Tm3+, Yb3+ doped SrF2 nanoparticlesVisible and near infrared upconversion emission from Tm3+, Yb3+ doped SrF2 nanoparticles591597165110.47176/ijpr.20.4.37861FAMGhorashiInstitute for Nanoscience and Nanotechnology, Sharif University of Technology, Tehran, IranH RMadaah-HosseiniDepartment of Materials Science and Engineering, Sharif University of Technology, Tehran, IranEMohajeraniLaser and Plasma Research Institute, Shahid Beheshti University, Tehran, IranJournal Article20190519Tm<sup>3+</sup>, Yb<sup>3+</sup>-codoped SrF<sub>2</sub> nanoparticles were synthesized through a facile hydrothermal technique. Citrate ions were introduced as the capping agent into the reaction. Upconversion nanoparticles were characterized by field emission scanning electron microscopy (FESEM), Energy dispersive x-ray spectroscopy (EDS), x-ray diffraction (XRD), Dynamic light scattering (DLS), Zeta potential, Fourier transform Infrared spectroscopy (Ft-IR), and the 980 nm laser induced photoluminescence spectroscopy. Rare-earth ions (Na<sup>+</sup>), which are the cations of citrate salts, are incorporated into the structure to act as charge compensators. Upconversion emission in the visible and NIR region was observed by the 980 nm irradiation. Nanoparticles with a narrow size distribution and a uniform morphology were directly dispersible in water, forming a quite transparent suspension. Nanoparticles size was approximately 10 nm. High penetration of the Near-Infrared light into the body tissue makes these nanoparticles appropriate for tumor targeting in the deeper tissues for the purpose of bioimaging and photodynamic therapy.
Tm<sup>3+</sup>, Yb<sup>3+</sup>-codoped SrF<sub>2</sub> nanoparticles were synthesized through a facile hydrothermal technique. Citrate ions were introduced as the capping agent into the reaction. Upconversion nanoparticles were characterized by field emission scanning electron microscopy (FESEM), Energy dispersive x-ray spectroscopy (EDS), x-ray diffraction (XRD), Dynamic light scattering (DLS), Zeta potential, Fourier transform Infrared spectroscopy (Ft-IR), and the 980 nm laser induced photoluminescence spectroscopy. Rare-earth ions (Na<sup>+</sup>), which are the cations of citrate salts, are incorporated into the structure to act as charge compensators. Upconversion emission in the visible and NIR region was observed by the 980 nm irradiation. Nanoparticles with a narrow size distribution and a uniform morphology were directly dispersible in water, forming a quite transparent suspension. Nanoparticles size was approximately 10 nm. High penetration of the Near-Infrared light into the body tissue makes these nanoparticles appropriate for tumor targeting in the deeper tissues for the purpose of bioimaging and photodynamic therapy.
Isfahan University of Technology,
The Physics Society of IranIranian Journal of Physics Research1682-695720420210219Assessment of the absorbed dose uncertainty of prostate due to tissue swelling and radioactive sources displacement in brachytherapy using
Monte Carlo methodAssessment of the absorbed dose uncertainty of prostate due to tissue swelling and radioactive sources displacement in brachytherapy using
Monte Carlo method599613165210.47176/ijpr.20.4.41043FAZAghaeiPhysics Department , Isfahan University of Technology, Isfahan, IranAlirezaKarimianDepartment of Biomedical Engineering, Faculty of Engineering, University of Isfahan0000-0003-2543-4772M HAlamatsazPhysics Department , Isfahan University of Technology, Isfahan, IranJournal Article20200414Brachytherapy is a kind of cancer treatment in which radiation sources are implanted inside or close to the cancerous tissue. The purpose of this research is to calculate the absorbed dose uncertainty of prostate tissue, due to its swelling, displacement of the implanted seed sources and also, to address the effect of these factors simultaneously, in brachytherapy of prostate. In this research, MCNPX2.6 code, the TG-43U1 protocol and ORNL body phantom were used to simulate the brachytherapy of prostate using iodine-125 seed sources. In the first study, 84 sources of iodine with the shapes of seed and then points were implanted inside the prostate with the volume of 38.01 cm<sup>3</sup>. The radiation absorbed dose was found to be 110.59 and 110.57 Gy, respectively. Considering the 50% prostate inflation after implantation, the radiation absorbed doses of prostate showed a reduction of more than of 17%. In the second therapeutic plan, by using 76 seed sources of I-125, considering 12% swelling of prostate and applying the displacement of seed sources in three directions: left–right (1.8mm), front-back (2.1mm) and top–down (3.4mm)), the radiation dose amount of the cancerous tissue was reduced about 21%. So, the results of seed and point sources of brachytherapy were very close to each other. Therefore, in simulation studies, point sources can be used instead of seed sources to reduce the computational complexity. Also, this research showed the effects of swelling and displacement of brachytherapy sources on the amount of the absorbed dose of prostate and its treatment were noteworthy.Brachytherapy is a kind of cancer treatment in which radiation sources are implanted inside or close to the cancerous tissue. The purpose of this research is to calculate the absorbed dose uncertainty of prostate tissue, due to its swelling, displacement of the implanted seed sources and also, to address the effect of these factors simultaneously, in brachytherapy of prostate. In this research, MCNPX2.6 code, the TG-43U1 protocol and ORNL body phantom were used to simulate the brachytherapy of prostate using iodine-125 seed sources. In the first study, 84 sources of iodine with the shapes of seed and then points were implanted inside the prostate with the volume of 38.01 cm<sup>3</sup>. The radiation absorbed dose was found to be 110.59 and 110.57 Gy, respectively. Considering the 50% prostate inflation after implantation, the radiation absorbed doses of prostate showed a reduction of more than of 17%. In the second therapeutic plan, by using 76 seed sources of I-125, considering 12% swelling of prostate and applying the displacement of seed sources in three directions: left–right (1.8mm), front-back (2.1mm) and top–down (3.4mm)), the radiation dose amount of the cancerous tissue was reduced about 21%. So, the results of seed and point sources of brachytherapy were very close to each other. Therefore, in simulation studies, point sources can be used instead of seed sources to reduce the computational complexity. Also, this research showed the effects of swelling and displacement of brachytherapy sources on the amount of the absorbed dose of prostate and its treatment were noteworthy.Isfahan University of Technology,
The Physics Society of IranIranian Journal of Physics Research1682-695720420210219Investigation of factors affecting on the efficiency of second harmonic generation of the continuous-wave focused Gaussian beam of 1064 nm inside the periodically poled nonlinear crystalsInvestigation of factors affecting on the efficiency of second harmonic generation of the continuous-wave focused Gaussian beam of 1064 nm inside the periodically poled nonlinear crystals615625165310.47176/ijpr.20.4.37381FAHAmrollahiLaser and Plasma Research Institute, Shahid Beheshti University, Tehran, IranAArabanianLaser and Plasma Research Institute, Shahid Beheshti University, Tehran, IranJournal Article20190404In this research, the nonlinear propagation equations of the fundamental and second harmonic waves coupled to the heat equation are solved for a focused Guassian beam inside two quasi-phase matched periodically poled MgO: PPLN and MgO: PPLT crystals, and the optimum focal length and radius of the continuous-wave laser beam with the wavelength of 1064 nm and with Gaussian profile, and also, the optimal phase-mismached parameter are calculated and the dependence of the second harmonic efficiency on these parameters is shown. Also, the effects of the thermal distribution inside the crystal on the second harmonic generation efficiency are investigated and it is shown how the thermal distribution reduces the second harmonic efficiency and, accordingly, the optimal crystal length for different incident powers is determined and shown that the lower crystal lengths should be selected for higher incident powers. Finally, a comparison between the second harmonic efficiencies in two crystals of MgO: PPLN and MgO: PPLT is performed considering the thermal distribution for different insident powers and it is shown that for the lower/ higher incident power than 21 watts, the crystal of MgO: PPLN / MgO: PPLT is more suitable and more efficient for second harmonic generation.In this research, the nonlinear propagation equations of the fundamental and second harmonic waves coupled to the heat equation are solved for a focused Guassian beam inside two quasi-phase matched periodically poled MgO: PPLN and MgO: PPLT crystals, and the optimum focal length and radius of the continuous-wave laser beam with the wavelength of 1064 nm and with Gaussian profile, and also, the optimal phase-mismached parameter are calculated and the dependence of the second harmonic efficiency on these parameters is shown. Also, the effects of the thermal distribution inside the crystal on the second harmonic generation efficiency are investigated and it is shown how the thermal distribution reduces the second harmonic efficiency and, accordingly, the optimal crystal length for different incident powers is determined and shown that the lower crystal lengths should be selected for higher incident powers. Finally, a comparison between the second harmonic efficiencies in two crystals of MgO: PPLN and MgO: PPLT is performed considering the thermal distribution for different insident powers and it is shown that for the lower/ higher incident power than 21 watts, the crystal of MgO: PPLN / MgO: PPLT is more suitable and more efficient for second harmonic generation.Isfahan University of Technology,
The Physics Society of IranIranian Journal of Physics Research1682-695720420210219Nonlinear coupling of two nonlinear coupled plasmonic nanowires in the presence of Kerr and two-photon absorption in the modes of TM00 and TM10Nonlinear coupling of two nonlinear coupled plasmonic nanowires in the presence of Kerr and two-photon absorption in the modes of TM00 and TM10627635165410.47176/ijpr.20.4.71084FAAGhadiAtomic and Molecular Physics Group, Faculty of Basic Sciences, University of Mazandaran, Iranhttps://orcid.org/00FHabibiAtomic and Molecular Physics Group, Faculty of Basic Sciences, University of Mazandaran, IranSMirzanejhadAtomic and Molecular Physics Group, Faculty of Basic Sciences, University of Mazandaran, IranJournal Article20200702The nonlinear interactions of coupled nanowires are important phenomena in data processing of integrated photonic circuits. In this paper, we investigate the nonlinear coupling of two silver nonlinear coupled plasmonic nanowires for TM00 and TM10 modes under different amplitudes in the presence of Kerr effect, and the other case that the medium has Kerr and two photon absorption (TPA) effect too. The results show that in the presence of TPA effect the nonlinear optical effects appear in lower input amplitudes than Kerr effect. The Kerr effect occurs in upper intensities than the TPA effect and nonlinear optical effect leads to decrease the exchange of plasmonic waves between two nanowires. Also, the coupling length (Lc), that it means the characteristic length of the structure has a lower coupling distance that through propagating in the medium the transfer of the wave is completely, in TM00 mode is lower than TM10 mode. Also, the results show that for different values of initial amplitudes of field in a fixed value of Lc, the coupling efficiency increases with increasing the value of intensity.The nonlinear interactions of coupled nanowires are important phenomena in data processing of integrated photonic circuits. In this paper, we investigate the nonlinear coupling of two silver nonlinear coupled plasmonic nanowires for TM00 and TM10 modes under different amplitudes in the presence of Kerr effect, and the other case that the medium has Kerr and two photon absorption (TPA) effect too. The results show that in the presence of TPA effect the nonlinear optical effects appear in lower input amplitudes than Kerr effect. The Kerr effect occurs in upper intensities than the TPA effect and nonlinear optical effect leads to decrease the exchange of plasmonic waves between two nanowires. Also, the coupling length (Lc), that it means the characteristic length of the structure has a lower coupling distance that through propagating in the medium the transfer of the wave is completely, in TM00 mode is lower than TM10 mode. Also, the results show that for different values of initial amplitudes of field in a fixed value of Lc, the coupling efficiency increases with increasing the value of intensity.Isfahan University of Technology,
The Physics Society of IranIranian Journal of Physics Research1682-695720420210219Effective quadruple deformation of (128-160)Nd isotopic chainEffective quadruple deformation of (128-160)Nd isotopic chain637647165510.47176/ijpr.20.4.51061FAAHosseinnezhadDepartment of Physics, University of Tabriz, Tabriz, Iran0000-0002-3977-3962AJalili MajarashinDepartment of Physics, Liaoning Normal University, Dalian, ChinaHSabriDepartment of Physics, University of Tabriz, Tabriz, IranPFengDepartment of Physics, Liaoning Normal University, Dalian, ChinaJournal Article20200523The aim of this paper is to calculate the effective quadruple deformation of different levels in the Nd isotopic chain in the framework of the boson interaction model. For this purpose, by labeling the selected states in the form of the dynamic limit of U(5), the expectation value of the quadruple interaction operator is calculated and the quadruple shape invariant and the Effective quadruple deformation of levels are obtained and compared to the corresponding experimental values, the effective boson charge for each isotope has been determined. The results show the existence of overlap in the values of the effective quadruple deformation of 0_3^+ and 2_1^+ levels in this isotopic chain. Also, a certain relationship is observed between the effective quadruple deformation values and the effective Boson charge and the spacing of the levels. The existence of this dependence for the Nd isotopic chain and the overlap of quantities can be reported as signs of shape coexistence in (_60^140)Nd and (_60^142)Nd and (_60^146)Nd isotopes.The aim of this paper is to calculate the effective quadruple deformation of different levels in the Nd isotopic chain in the framework of the boson interaction model. For this purpose, by labeling the selected states in the form of the dynamic limit of U(5), the expectation value of the quadruple interaction operator is calculated and the quadruple shape invariant and the Effective quadruple deformation of levels are obtained and compared to the corresponding experimental values, the effective boson charge for each isotope has been determined. The results show the existence of overlap in the values of the effective quadruple deformation of 0_3^+ and 2_1^+ levels in this isotopic chain. Also, a certain relationship is observed between the effective quadruple deformation values and the effective Boson charge and the spacing of the levels. The existence of this dependence for the Nd isotopic chain and the overlap of quantities can be reported as signs of shape coexistence in (_60^140)Nd and (_60^142)Nd and (_60^146)Nd isotopes.Isfahan University of Technology,
The Physics Society of IranIranian Journal of Physics Research1682-695720420210219New Methode for Synthesis of PbO Nano-Rods and its application in ionizing radiation shieldingNew Methode for Synthesis of PbO Nano-Rods and its application in ionizing radiation shielding649655165610.47176/ijpr.20.4.38211FASYazdani DarkiNuclear Physics Division, Physics Department, University of Yazd, Yazd, IranMEslami-KalantariNuclear Physics Division, Physics Department, University of Yazd, Yazd, IranHZareSolid State Physics Division, Physics Department, University of Yazd, Yazd, IranJournal Article20190625We successfully synthesized PbO nanorods by a simple and low-cost approach using Pb(CH<sub>3</sub>COO)<sub>2</sub>.3H<sub>2</sub>O, NaOH as the starting materials without any surfactants in water media at room temperature. Scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), x-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), ultraviolet–visible spectroscopy (UV–Vis), and photoluminescence spectrophotometer (PL) were used to characterize the samples. The prepared nanorods had the average diameter of about 40 nm, the average length of about 6 µm and the average crystallite size of about 57 nm. PbO nanorods showed good gamma and beta attenuation; so, they could be considered as a potential candidate for radiation shielding.We successfully synthesized PbO nanorods by a simple and low-cost approach using Pb(CH<sub>3</sub>COO)<sub>2</sub>.3H<sub>2</sub>O, NaOH as the starting materials without any surfactants in water media at room temperature. Scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), x-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), ultraviolet–visible spectroscopy (UV–Vis), and photoluminescence spectrophotometer (PL) were used to characterize the samples. The prepared nanorods had the average diameter of about 40 nm, the average length of about 6 µm and the average crystallite size of about 57 nm. PbO nanorods showed good gamma and beta attenuation; so, they could be considered as a potential candidate for radiation shielding.Isfahan University of Technology,
The Physics Society of IranIranian Journal of Physics Research1682-695720420210219Investigation of Laser wakefield acceleration using relativistic
Vlasov-Maxwell codeInvestigation of Laser wakefield acceleration using relativistic
Vlasov-Maxwell code657665165710.47176/ijpr.20.4.31754FAMGhorbanaliluDepartment of Physics, University of Shahid Beheshti, Tehran, IranS.NRazaviniaDepartment of Physics, University of Shahid Beheshti, Tehran, IranJournal Article20190317In this paper we investigate the electron laser wakefield acceleration using numerical solution of relativistic Vlasov-Maxwell equations with Semi-Lagrangian method. We found optimum pulse length to excite strong wakefields by investigation of electric fields and density variation, which caused by propagation of intense relativistic laser pulse through underdense plasma as well as average kinetic energy of electrons, for lasers with different pulse lengths. <br /> In this paper we investigate the electron laser wakefield acceleration using numerical solution of relativistic Vlasov-Maxwell equations with Semi-Lagrangian method. We found optimum pulse length to excite strong wakefields by investigation of electric fields and density variation, which caused by propagation of intense relativistic laser pulse through underdense plasma as well as average kinetic energy of electrons, for lasers with different pulse lengths. <br /> Isfahan University of Technology,
The Physics Society of IranIranian Journal of Physics Research1682-695720420210219Application of the residual surface delta interaction in the /beta+ decay of (_^"40" )"Sc" nucleusApplication of the residual surface delta interaction in the /beta+ decay of (_^"40" )"Sc" nucleus667679165810.47176/ijpr.20.4.19642FAAYarahmadiDepartment of Physics, Faculty of Science, University of Sistan and Baluchestan, Zahedan, IranVDehghaniDepartment of Physics, Faculty of Science, University of Sistan and Baluchestan, Zahedan, IranS AAlaviDepartment of Physics, Faculty of Science, University of Sistan and Baluchestan, Zahedan, IranJournal Article20190511In this paper the beta decay of Sc40 has been investigated. Using the eigenfunctions of the spherical oscillator the eigenvalues and eigenfunctions of the Woods-Saxon potential with spin-orbit and Coulomb terms have been calculated. In order to obtain the more realistic nuclear wave functions, the surface delta interaction potential has been used as the residual interaction between the valence nucleons in the frame work of Tamm-Dancoff approximation (TDA) in the case of Ca40 and particle-hole Tamm-Dancoff approximation (pnTDA) in the case of Sc40 . The potential constants have been obtained by fitting the results with the experimental data. The half-life and transition probability of positive beta decay of Sc40 have been calculated. Good greement with the experimental data was observed.In this paper the beta decay of Sc40 has been investigated. Using the eigenfunctions of the spherical oscillator the eigenvalues and eigenfunctions of the Woods-Saxon potential with spin-orbit and Coulomb terms have been calculated. In order to obtain the more realistic nuclear wave functions, the surface delta interaction potential has been used as the residual interaction between the valence nucleons in the frame work of Tamm-Dancoff approximation (TDA) in the case of Ca40 and particle-hole Tamm-Dancoff approximation (pnTDA) in the case of Sc40 . The potential constants have been obtained by fitting the results with the experimental data. The half-life and transition probability of positive beta decay of Sc40 have been calculated. Good greement with the experimental data was observed.Isfahan University of Technology,
The Physics Society of IranIranian Journal of Physics Research1682-695720420210219Generation of new modes in the process of passing waves through two semi-bounded waveguides with cylindrical metallic wall , with a dissipative plasma rod in one of themGeneration of new modes in the process of passing waves through two semi-bounded waveguides with cylindrical metallic wall , with a dissipative plasma rod in one of them681691165910.47176/ijpr.20.4.15883FASNajari Faculty of Physics, Department of Photonics and Plasma, University of Kashan, Kashan, IranBJazi Faculty of Physics, Department of Photonics and Plasma, University of Kashan, Kashan, IranJournal Article20190527In this paper, the generation of the new modes in the problem of the transfer of the electromagnetic waves from a semi-bounded cylindrical waveguide with a metallic wall to a plasma column are investigated. An electromagnetic wave with the symmetric mode TM0j is send from a semi-bounded cylindrical dielectric waveguide to a plasma column. The plasma column is placed on the axis of another semi-bounded dielectric waveguide. Two mentioned waveguides are connected to each other in z=0. The incident wave is reflected and transmitted on the interface surface of two waveguides. The reflected and transmitted waves are considered as a series of the new modes and by using appropriate boundary conditions, the reflection and transmission coefficients of each new mode are calculated. The calculations are shown that the reflection and transmission coefficients of the reflected and transmitted waves are a function of the collision frequency of the plasma. Also, the phase different of the reflected and transmitted waves respect to the incident are shown because the reflection and transmission coefficients are obtained as a complex number. The graphs of the transmission and reflection coefficients and the graphs of the phase difference of the reflected and transmitted waves in terms of the collision frequency of the plasma are investigated.In this paper, the generation of the new modes in the problem of the transfer of the electromagnetic waves from a semi-bounded cylindrical waveguide with a metallic wall to a plasma column are investigated. An electromagnetic wave with the symmetric mode TM0j is send from a semi-bounded cylindrical dielectric waveguide to a plasma column. The plasma column is placed on the axis of another semi-bounded dielectric waveguide. Two mentioned waveguides are connected to each other in z=0. The incident wave is reflected and transmitted on the interface surface of two waveguides. The reflected and transmitted waves are considered as a series of the new modes and by using appropriate boundary conditions, the reflection and transmission coefficients of each new mode are calculated. The calculations are shown that the reflection and transmission coefficients of the reflected and transmitted waves are a function of the collision frequency of the plasma. Also, the phase different of the reflected and transmitted waves respect to the incident are shown because the reflection and transmission coefficients are obtained as a complex number. The graphs of the transmission and reflection coefficients and the graphs of the phase difference of the reflected and transmitted waves in terms of the collision frequency of the plasma are investigated.Isfahan University of Technology,
The Physics Society of IranIranian Journal of Physics Research1682-695720420210219Study of spinning particles around rotating black holesStudy of spinning particles around rotating black holes693698166010.47176/ijpr.20.4.37971FAJKhodagholizadehDepartment of Physics, Farhangian University, Tehran, Iran AVahediDepartment of Physics, Kharazmi university, Tehran, Iran Journal Article20190610The orbital velocity profile around the Kerr black holes has a non-monotonic radial behavior in the Locally Nonrotating Frames (LNRF). Using Mathisson- Papapetrou- Dixon equation for a massive spinning particle, again this maximum-minimum feature has been shown by considering the linear spin approximation. Also the spin of black holes and absolute value of particle's spin have an important rule in Aschenbach effect.
The orbital velocity profile around the Kerr black holes has a non-monotonic radial behavior in the Locally Nonrotating Frames (LNRF). Using Mathisson- Papapetrou- Dixon equation for a massive spinning particle, again this maximum-minimum feature has been shown by considering the linear spin approximation. Also the spin of black holes and absolute value of particle's spin have an important rule in Aschenbach effect.
Isfahan University of Technology,
The Physics Society of IranIranian Journal of Physics Research1682-695720420210219Comparison of polarization sensitive second harmonic generation microscopy techniques for the study of biological tissuesComparison of polarization sensitive second harmonic generation microscopy techniques for the study of biological tissues699709166110.47176/ijpr.20.4.61079FAMAlizadeh Department of Physics, University of Kurdistan, Sanandaj, Iran MGhotbi Department of Physics, University of Kurdistan, Sanandaj, Iran 0000-0002-4134-7188Journal Article20200622Recently, polarization sensitive Second Harmonic Generation (pSHG) microscopy has become a powerful tool for the study of the noncenterosymmetric biological structures. This is due to the fact that pSHG has some intrinsically benefits such as high resolution and contrast, and it can also penetrate deeply inside the sample in a noninvasive manner. One drawback for the pSHG technique is that the imaging procedure is not fast enough to study in vivo samples or to monitor the dynamics of different tissues. This issue imposes some limitations on using the pSHG technique to study in vivo samples. Fortunately, recently Single Scan polarization sensitive Second Harmonic Generation (SS-pSHG) technique has been introduced as a fast alternative for the conventional pSHG technique. In this article, the results obtained from ex vivo biological samples of starch, human cornea and animal tendon have been compared in a pixel-to-pixel manner using pSHG and SS-pSHG techniques in forward direction. Even though the samples used here are ex vivo, the results of this study promise that the polarization sensitive SHG microscopy techniques have a great potential to study biological tissues in a noninvasive procedure. This issue is more important especially in the cases that samples are in vivo.Recently, polarization sensitive Second Harmonic Generation (pSHG) microscopy has become a powerful tool for the study of the noncenterosymmetric biological structures. This is due to the fact that pSHG has some intrinsically benefits such as high resolution and contrast, and it can also penetrate deeply inside the sample in a noninvasive manner. One drawback for the pSHG technique is that the imaging procedure is not fast enough to study in vivo samples or to monitor the dynamics of different tissues. This issue imposes some limitations on using the pSHG technique to study in vivo samples. Fortunately, recently Single Scan polarization sensitive Second Harmonic Generation (SS-pSHG) technique has been introduced as a fast alternative for the conventional pSHG technique. In this article, the results obtained from ex vivo biological samples of starch, human cornea and animal tendon have been compared in a pixel-to-pixel manner using pSHG and SS-pSHG techniques in forward direction. Even though the samples used here are ex vivo, the results of this study promise that the polarization sensitive SHG microscopy techniques have a great potential to study biological tissues in a noninvasive procedure. This issue is more important especially in the cases that samples are in vivo.Isfahan University of Technology,
The Physics Society of IranIranian Journal of Physics Research1682-695720420210219Simulation of possibility of detecting gamma rays emitted from
crab by Alborz-I arraySimulation of possibility of detecting gamma rays emitted from
crab by Alborz-I array711716166210.47176/ijpr.20.4.71099FAYPezeshkian1. Department of Physics, Sahand University of Technology, Tabriz, Iran
2. Alborz Observatory, Sharif University of Technology, Tehran, Iran 0000-0001-5932-8551ALaletaheriDepartment of Physics, University of Zanjan, Zanjan, Iran Journal Article20200726Crab Nebula, as an active source of high energy gamma-rays, is a common standard source used for calibrating different gamma-ray telescopes and observatories. Since gamma rays with energies above 100 TeV from crab is reported, it is possible to detect gamma rays emitted from this nebula by a suitable ground based detector array. Alborz-I array is designed to study cosmic rays with energies around the knee of cosmic ray spectrum. In this paper, it is shown that the current location and configuration of Alborz-I, makes it impossible to detect Crab gamma rays. Our simulation shows that the average rate of gamma particle detection reaches to something above 1 gamma particle in 2 years, which is very difficult to distinguish from cosmic ray background. Finally some proposals to constructing an array with capability of detecting Crab gamma rays are presented.Crab Nebula, as an active source of high energy gamma-rays, is a common standard source used for calibrating different gamma-ray telescopes and observatories. Since gamma rays with energies above 100 TeV from crab is reported, it is possible to detect gamma rays emitted from this nebula by a suitable ground based detector array. Alborz-I array is designed to study cosmic rays with energies around the knee of cosmic ray spectrum. In this paper, it is shown that the current location and configuration of Alborz-I, makes it impossible to detect Crab gamma rays. Our simulation shows that the average rate of gamma particle detection reaches to something above 1 gamma particle in 2 years, which is very difficult to distinguish from cosmic ray background. Finally some proposals to constructing an array with capability of detecting Crab gamma rays are presented.Isfahan University of Technology,
The Physics Society of IranIranian Journal of Physics Research1682-695720420210219Investigation of multi-quark systemsInvestigation of multi-quark systems717725166310.47176/ijpr.20.4.41048FAFAbdiPhysics department, Razi University, KermanshahG. RBoroun Physics department, Razi University, Kermanshah, Iran 0000-0002-2517-247xJournal Article20200424In this study, the researcher decided to study Tetraquark and Pentaquark systems. We introduce the Pentaquark system as a meson-baryon system and Tetraquark as a diquark-antidiquark system. A diquark consists of two quarks. The interaction potential between these particles is considered as a combination of two color charge potentials and the confinement potential is considered as harmonic and linear sentences. Solve the Schrodinger equation by considering the effects of spin-spin, isospin- isospin, spin-isospin, and then obtain the mass of the diquark and the heavy tetraquuarks with charm quarks and bottom. These calculations are calculated using the approach of diquark - antidiquark within the framework of the non-relativistic quark model. In the following, we calculate the mass of Pentaquark systems in the same way.In this study, the researcher decided to study Tetraquark and Pentaquark systems. We introduce the Pentaquark system as a meson-baryon system and Tetraquark as a diquark-antidiquark system. A diquark consists of two quarks. The interaction potential between these particles is considered as a combination of two color charge potentials and the confinement potential is considered as harmonic and linear sentences. Solve the Schrodinger equation by considering the effects of spin-spin, isospin- isospin, spin-isospin, and then obtain the mass of the diquark and the heavy tetraquuarks with charm quarks and bottom. These calculations are calculated using the approach of diquark - antidiquark within the framework of the non-relativistic quark model. In the following, we calculate the mass of Pentaquark systems in the same way.Isfahan University of Technology,
The Physics Society of IranIranian Journal of Physics Research1682-695720420210219Warm intermediate and logamediate cosmic inflation with a constant dissipation coefficient in loop quantum gravityWarm intermediate and logamediate cosmic inflation with a constant dissipation coefficient in loop quantum gravity727735166410.47176/ijpr.20.4.37311FAARavanpakDepartment of Physics, Faculty of Science, Vali-e-Asr University of Rafsanjan, Rafsanjan, IranM RSetareDepartment of Science, Campus of Bijar, University of Kurdistan, Bijar, IranJournal Article20190322Warm inflationary model in the context of loop quantum cosmology is investigated. To this aim we consider two cases intermediate inflation and logamediate inflation. In both the cases, assuming a constant dissipation coefficient, we study the model under consideration in weak dissipation regime and also in strong dissipation regime. In each of these cases, we obtain various parameters such as potential function of inflationary scalar field and slow-roll parameters. Perturbation theory and also finding relations between perturbative parameters is studied.Warm inflationary model in the context of loop quantum cosmology is investigated. To this aim we consider two cases intermediate inflation and logamediate inflation. In both the cases, assuming a constant dissipation coefficient, we study the model under consideration in weak dissipation regime and also in strong dissipation regime. In each of these cases, we obtain various parameters such as potential function of inflationary scalar field and slow-roll parameters. Perturbation theory and also finding relations between perturbative parameters is studied.Isfahan University of Technology,
The Physics Society of IranIranian Journal of Physics Research1682-695720420210219Thin accretion disks around multi-polytropic wormholeThin accretion disks around multi-polytropic wormhole737746166510.47176/ijpr.20.4.71085FAMHeydari-Fard Department of Physics, The University of Qom, Qom, IranFEghbalpoor Department of Physics, The University of Qom, Qom, IranJournal Article20200705In this paper, we study the physical properties of thin accretion disks in static and spherically symmetric multi-polytropic wormhole space-time. Using the Novikov-Thorne model, the electromagnetic flux, temperature distribution, innermost stable circular orbits and radiative efficiency of thin disks are obtained. Comparing the results with traversable wormholes obtained by Morris and Thorne (TWH) and the Schwarzschild solution, we show that thin accretion disks around multi-polytropic wormhole geometry are more luminous and more efficient than the TWH and Schwarzschild black hole.In this paper, we study the physical properties of thin accretion disks in static and spherically symmetric multi-polytropic wormhole space-time. Using the Novikov-Thorne model, the electromagnetic flux, temperature distribution, innermost stable circular orbits and radiative efficiency of thin disks are obtained. Comparing the results with traversable wormholes obtained by Morris and Thorne (TWH) and the Schwarzschild solution, we show that thin accretion disks around multi-polytropic wormhole geometry are more luminous and more efficient than the TWH and Schwarzschild black hole.Isfahan University of Technology,
The Physics Society of IranIranian Journal of Physics Research1682-695720420210219Conceptual design, manufacturing and investigation of dipole plasma antenna with the capability of frequency variation in the VHF bandConceptual design, manufacturing and investigation of dipole plasma antenna with the capability of frequency variation in the VHF band747758166610.47176/ijpr.20.4.27821FAMAmiri Department of Physics, University of Mohaghegh Ardabili, Ardabil, IranNSepehri Javan Department of Physics, University of Mohaghegh Ardabili, Ardabil, IranJournal Article20190527In this article, we simulate and manufacture a dipole plasma antenna whose frequency is variable in the VHF band. The conductive medium of antenna is the plasma created by the DC discharge in a glass tube. To excite the antenna, we use a cylindrical aluminum coupler installed at the middle of the antenna. By varying values of gas pressure, input impedance of circuit and the voltage deference between two ends of the plasma medium, one can change the working area of antenna at a few hundred gigahertz frequency interval. Simulation and numerical calculations are carried out for an antenna with 78cm length and 2cm radius at 0.8 bar pressure exerted under 15KV voltage difference. At constant pressure, by using some parallel resistors in the antenna circuit, the impedance of discharge circuit is changed and consequently the plasma density is varied. For plasma frequencies and , using semi-experimental formulae, analysis shows resonances at frequencies 250MHz and 311MHz, respectively, which are in good agreement with the experimental results which take place at frequencies 217MHz and 272MHz. Additionally, simulation is accomplished for a metal antenna with corresponding geometry whose working frequency detected at 184MHz.In this article, we simulate and manufacture a dipole plasma antenna whose frequency is variable in the VHF band. The conductive medium of antenna is the plasma created by the DC discharge in a glass tube. To excite the antenna, we use a cylindrical aluminum coupler installed at the middle of the antenna. By varying values of gas pressure, input impedance of circuit and the voltage deference between two ends of the plasma medium, one can change the working area of antenna at a few hundred gigahertz frequency interval. Simulation and numerical calculations are carried out for an antenna with 78cm length and 2cm radius at 0.8 bar pressure exerted under 15KV voltage difference. At constant pressure, by using some parallel resistors in the antenna circuit, the impedance of discharge circuit is changed and consequently the plasma density is varied. For plasma frequencies and , using semi-experimental formulae, analysis shows resonances at frequencies 250MHz and 311MHz, respectively, which are in good agreement with the experimental results which take place at frequencies 217MHz and 272MHz. Additionally, simulation is accomplished for a metal antenna with corresponding geometry whose working frequency detected at 184MHz.Isfahan University of Technology,
The Physics Society of IranIranian Journal of Physics Research1682-695720420210219Comparison of mechanical, optical and electronic transport properties of isotropic and anisotropic borophospheneComparison of mechanical, optical and electronic transport properties of isotropic and anisotropic borophosphene759771166710.47176/ijpr.20.4.11149FAMPashangpour Department of Physics, Islamshahr Branch, Islamic Azad University, Islamshahr, Iran0000-0002-7827-359XJournal Article20201110In this research, mechanical, optical and electronic transport properties of two phases of graphene-like borophosphene are investigated using density functional theory. Graphene-like borophosphene, a honeycomb structure with equal ratio of boron and phosphorus atoms, is introduced in two isotropic and anisotropic phases. For this purpose, band structure, partial density of states, Young’s modulus, Poisson ratios, dielectric function, and current-voltage characteristics are calculated and compared. The results show that the anisotropic phase of graphene-like borophosphene is semimetal and the isotropic phase is a semiconductor with a direct energy gap of 0.9 eV. Moreover, the Young’s modulus has the highest values for both phases in the zigzag and armchair directions of crystal, and the Poisson ratio has the lowest values in these two directions. Besides, optical properties of these two structures include electron energy loss spectroscopy, refractive index, extinction coefficient, optical conductivity and reflection coefficient for parallel and perpendicular polarization of electric fields respect to the sheets are computed by real and imaginary parts of dielectric function using random phase approximation. Plasmon’s energies are obtained 2.24 and 8.88 eV in the armchair direction and 9.01 eV in the zigzag direction for the anisotropic phase and for the isotropic phase, 3.38 and 9.12 eV are obtained in both directions. Both phases are transparent respect to visible light polarized in the perpendicular direction to the crystal, and the reflection and absorption are zero. Due to the selective transmission / absorption / reflection of the electromagnetic wave in the crystals, this material is suggested as a suitable candidate in the fabrication of nano optoelectronic devices. Furthermore, Ohmic behavior is observed in current-voltage characteristics of the isotropic phase after the threshold bias voltage of 0.9 V. As a result of the high Fermi velocity of charge carriers in the anisotropic phase of borophosphene ( ), this material can be used in nanoelectronic devices.In this research, mechanical, optical and electronic transport properties of two phases of graphene-like borophosphene are investigated using density functional theory. Graphene-like borophosphene, a honeycomb structure with equal ratio of boron and phosphorus atoms, is introduced in two isotropic and anisotropic phases. For this purpose, band structure, partial density of states, Young’s modulus, Poisson ratios, dielectric function, and current-voltage characteristics are calculated and compared. The results show that the anisotropic phase of graphene-like borophosphene is semimetal and the isotropic phase is a semiconductor with a direct energy gap of 0.9 eV. Moreover, the Young’s modulus has the highest values for both phases in the zigzag and armchair directions of crystal, and the Poisson ratio has the lowest values in these two directions. Besides, optical properties of these two structures include electron energy loss spectroscopy, refractive index, extinction coefficient, optical conductivity and reflection coefficient for parallel and perpendicular polarization of electric fields respect to the sheets are computed by real and imaginary parts of dielectric function using random phase approximation. Plasmon’s energies are obtained 2.24 and 8.88 eV in the armchair direction and 9.01 eV in the zigzag direction for the anisotropic phase and for the isotropic phase, 3.38 and 9.12 eV are obtained in both directions. Both phases are transparent respect to visible light polarized in the perpendicular direction to the crystal, and the reflection and absorption are zero. Due to the selective transmission / absorption / reflection of the electromagnetic wave in the crystals, this material is suggested as a suitable candidate in the fabrication of nano optoelectronic devices. Furthermore, Ohmic behavior is observed in current-voltage characteristics of the isotropic phase after the threshold bias voltage of 0.9 V. As a result of the high Fermi velocity of charge carriers in the anisotropic phase of borophosphene ( ), this material can be used in nanoelectronic devices.Isfahan University of Technology,
The Physics Society of IranIranian Journal of Physics Research1682-695720420210219Relativistic electron dynamics in ion channel guiding in the presence of a helical wiggler and an external oblique magnetic field Relativistic electron dynamics in ion channel guiding in the presence of a helical wiggler and an external oblique magnetic field 773778166810.47176/ijpr.20.4.1072FAAKargarian Plasma and Nuclear Fusion Research School, Nuclear Science and Technology Research Institute, Tehran, IranJournal Article20190617In this paper, the electron acceleration and its relativistic dynamics in an ion-channel formed due to the laser pulse propagation through the plasma and under influence of the ion channel space-charge and a heliacal wiggler as well as the oblique magnetic field have been investigated. The equations for investigation of the electron dynamics are the tree-dimension Lorentz equations. For analytical analysis of the obtained equations, a three-dimension single particle code and forth order Runge-Kutta method is used as well. The electron energy gain and the relativistic electron dynamics drastically are affected by the ion-channel potential and the helical wiggler and also the external oblique magnetic field. The results of this paper can be significant in the selection of the appropriate parameters for plasma-based accelerators design.In this paper, the electron acceleration and its relativistic dynamics in an ion-channel formed due to the laser pulse propagation through the plasma and under influence of the ion channel space-charge and a heliacal wiggler as well as the oblique magnetic field have been investigated. The equations for investigation of the electron dynamics are the tree-dimension Lorentz equations. For analytical analysis of the obtained equations, a three-dimension single particle code and forth order Runge-Kutta method is used as well. The electron energy gain and the relativistic electron dynamics drastically are affected by the ion-channel potential and the helical wiggler and also the external oblique magnetic field. The results of this paper can be significant in the selection of the appropriate parameters for plasma-based accelerators design.