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Öğe Structural and electronic properties of monolayer group III monochalcogenides (conferenceObject)(Amer Chemical Soc, 2019) Demirci, Salih; Avazli, Nurlan; Durgun, Engin; Jahangirov, Seymur…Öğe Double Differential Proton Emission Cross Sections for Structural Fusion Materials Mg-24(Amer Inst Physics, 2018) Demirelli, Gozde; Sarpun, Ismail H.; Oruncak, Bekir; Tel, Eyyup; Aydin, AbdullahIn this study, double differential proton emission cross sections of 24Mg target nuclei have been theoretically calculated by the TALYS 1.8 code at 14 MeV neutron incident energy. Theoretical calculated cross sections were compared with available experimental data in EXFOR nuclear data library. Furthermore, in theoretical calculations direct, compound and pre-equilibrium reaction contribution have been investigated. Theoretical and experimental values are in good agreement for all given emission angles.Öğe The (α,n) reaction cross-section calculations for some isotopes of iron group elements in the range of 5-20 MeV(E D P Sciences, 2017) Yildiz, ErcanIron group elements (Sc, Mn, Fe, Co, Ni) are especially very important because structural material selection in design of fusion-fission reactors is very crucial. Obtained results from the nuclear reactions using structural materials can be used developing for these structural materials some isotopes. For this reason, in this study the cross sections of Sc-45(alpha, n) V-48, Mn-55(alpha, n) Co-58, Fe-54(alpha, n) Ni-57, Co-59(alpha, n) Cu-62, Ni-62(alpha, n) Zn-65 reactions have been calculated at 5-20 MeV energy ranges by using TALYS 1.8 and NON-SMOKER codes. Obtained results were compared experimental data from EXFOR database.Öğe Determination of the effects of nuclear level density parameters on photofission cross sections of U-235 up to 20 MeV(E D P Sciences, 2017) Sarpun, Ismail Hakki; Aydin, Abdullah; Pekdogan, HakanThe level density models and level density parameters are two of important quantities for describing the properties of nuclei. Especially, the level density parameter has an important role as input in calculation of reaction cross sections. In this study, the cross sections on U-235(g,f) reaction were calculated for different level density models using the TALYS 1.6 code up to 20MeV gamma incident energies. First, it was determined the level density model that was the closest to the experimental data. Secondly, cross sections obtained for different level density parameters of this model were compared with experimental data from the EXFOR database. Thus it was determined the best level density parameter fit to experimental data.Öğe Double differential light charged particle emission cross sections for some structural fusion materials(E D P Sciences, 2017) Sarpun, Ismail Hakki; Aydin, Abdullah; Tel, EyyupIn fusion reactors, neutron induced radioactivity strongly depends on the irradiated material. So, a proper selection of structural materials will have been limited the radioactive inventory in a fusion reactor. First-wall and blanket components have high radioactivity concentration due to being the most flux-exposed structures. The main objective of fusion structural material research is the development and selection of materials for reactor components with good thermo-mechanical and physical properties, coupled with low-activation characteristics. Double differential light charged particle emission cross section, which is a fundamental data to determine nuclear heating and material damages in structural fusion material research, for some elements target nuclei have been calculated by the TALYS 1.8 nuclear reaction code at 14-15 MeV neutron incident energy and compared with available experimental data in EXFOR library. Direct, compound and pre-equilibrium reaction contribution have been theoretically calculated and dominant contribution have been determined for each emission of proton, deuteron and alpha particle.Öğe Theoretical investigation of cross sections and astrophysical S-factors for the Mo-92(alpha,n)Ru-95 and Mo-94(alpha,n)(97) Ru reactions(E D P Sciences, 2016) Aydin, Abdullah; Yildiz, Ercan; Sarpun, Ismail HakkiMolybdenum is commonly applied as a constructive material in different types of nuclear reactors. The cross sections of the Mo-92(alpha, n) Ru-95 and Mo-94(alpha, n) Ru-97 reactions have been calculated at 5-20 MeV energy ranges. In theoretical calculations, the TALYS1.6 and NON-SMOKER codes were used. Also the astrophysical S-factors were calculated. Results of our calculations were checked to the experimental data obtained from EXFOR database.Öğe Calculation of cross-sections and astrophysical s-factors for the 63 Cu(α,n) and 63 Cu(α,γ) reactions(E D P Sciences, 2015) Yildiz, Ercan; Aydin, Abdullah; Sarpun, Ismail Hakki; Tel, EyyupThe cross sections and astrophysical S-factors of the Cu-63(alpha,gamma) and Cu-63(alpha,n) reactions have been calculated. The radiative alpha capture reaction cross sections was calculated in the incident energy range of 3 to 10 MeV and the (alpha,n) reaction cross sections was calculated in the incident energy range of 7 and 16 MeV. In these theoretical calculations, the TALYS 1.6 and NON-SMOKER codes were used. Also for these reactions, it was calculated the astrophysical S-factors which describe the possibility of reaction in low energies. Obtained results were compared to the experimental data taken from EXFOR database.Öğe Investigation of the effects of nuclear level density parameters on the cross sections for the U-234(gamma,f) reaction(E D P Sciences, 2015) Pekdogan, Hakan; Aydin, Abdullah; Sarpun, Ismail HakkiIn this study, we have investigated the effects of nuclear level density parameters on the cross sections for the U-234(gamma,f) reaction up to 20 MeV. The cross sections on U-234(gamma,f) reaction were calculated for different level density models using the TALYS 1.6 code. First, it was determined the level density model that was the closest to the experimental data. Secondly, cross sections obtained for different level density parameters of this model were compared with experimental data from the EXFOR database. Thus it was determined the best level density parameter fit to experimental data.Öğe A study on nuclear properties of Zr, Nb, and Ta nuclei used as structural material in fusion reactor(E D P Sciences, 2015) Sahan, Halide; Tel, Eyyup; Sahan, Muhittin; Aydin, Abdullah; Sarpun, Ismail Hakki; Kara, Ayhan; Doner, MesutFusion has a practically limitless fuel supply and is attractive as an energy source. The main goal of fusion research is to construct and operate an energy generating system. Fusion researches also contains fusion structural materials used fusion reactors. Material issues are very important for development of fusion reactors. Therefore, a wide range of fusion structural materials have been considered for fusion energy applications. Zirconium (Zr), Niobium (Nb) and Tantalum (Ta) containing alloys are important structural materials for fusion reactors and many other fields. Naturally Zr includes the Zr-90 (%51.5), Zr-91 (%11.2), Zr-92 (%17.1), Zr-94 (%17.4), Zr-96 (%2.80) isotopes and Nb-93 and Ta-181 include the Nb-93 (%100) and Ta-181 (%99.98), respectively. In this study, the charge, mass, proton and neutron densities and the root-mean-square (rms) charge radii, rms nuclear mass radii, rms nuclear proton, and neutron radii have been calculated for Zr87-102, Nb-93,Ta-181 target nuclei isotopes by using the Hartree-Fock method with an effective Skyrme force with SKM*. The calculated results have been compared with those of the compiled experimental taken from Atomic Data and Nuclear Data Tables and theoretical values of other studies.Öğe SiGe Nanocrystal Formation In Pecvd Grown SiOX/Si/Ge/Si/SiOX Multilayers(World Scientific Publ Co Pte Ltd, 2009) Agan, Sedat; Aydınlı, AtillaWe have studied alternating germanium-silicon-silicon oxide layers of 41 nm thickness grown on Si substrates by plasma enhanced chemically vapor deposition. The compositions of the grown films were determined by X-ray photoelectron spectroscopy. The films were annealed at temperatures varying from 700 to 950 degrees C for 7.5 minutes under nitrogen atmosphere. High resolution cross section TEM images, electron diffraction and electron energy-loss spectroscopy as well as energy-dispersive X-ray analysis (EDAX) confirm presence of Ge nanocrystals in each layer. The effect of annealing on the Ge nanocrystal formation in multilayers was investigated by Raman spectroscopy and TEM.Öğe Description of Exotic Nuclei with the Interacting Boson Model(Amer Inst Physics, 2008) Boyukata, M.; Van Isacker, P.; Uluer, I.Even-even nuclei in the A similar to 100 mass region are investigated within the framework of the interacting boson model-1 (IBM-1). The study includes energy spectra and electric quadrupole transition properties of zirconium, molybdenum, ruthenium and palladium isotopes with neutron number N >= 54. A global parametrization of the IBM-1 hamiltonian is found leading to a description of 301 collective levels in 30 nuclei with a root-mean-square deviation from the observed level energies of 119 keV The geometric character of the nuclei can be visualized by plotting the potential energy surface V(beta, gamma) obtained from the IBM-1 hamiltonian in the classical limit. The parametrization established on the basis of known elements is then used to predict properties of the unknown. neutron-rich isotopes Zr-106, (MO)-M-112, Ru-116 and Pd-120.Öğe Synthesis and characterization of nanosized Cu/ZnO catalyst by polyol method(Amer Scientific Publishers, 2008) Altincekic, Tuba Guerkaynak; Boz, Ismail; Aktuerk, SelcukNanosized catalysts composed of metallic copper supported on zinc oxide have been synthesized by the polyol process. Average crystallite size of copper was between 10 and 45 nm. Cu/ZnO catalyst particles were characterized by various techniques, such as X-ray Powder Diffraction (XRD), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Selected Area Electron Diffraction (SAED), and dynamic light scattering analysis (DLS).Öğe Studies of Al-Ti AHoys by SEM(Amer Inst Physics, 2007) Yildiz, K.; Atici, Y.; Kelioglu, K.; Yasar, E.Al-Ti (1, 2 wt. %) alloys were investigated by Scanning Electron Microscopy (SEM). SEM observations and energy-dispersive x-ray analyses (EDX) showed that the phase structure of Al-Ti (1 %) alloy at 165 mu m/s is composed of Al matrix and C, Ni, Fe and Si particles and the Al-Ti (1 %) alloys at 16 and 8 mu m/s have only the Al matrix and C particles. It was also found that the Al-Ti (2 %) form the Al matrix and intermetallic TiAl.Öğe Formation of Ge nanocrystals and SiGe in PECVD grown SiNx: Ge thin films(Elsevier Sci Ltd, 2006) Dana, Aykutlu; Tokay, Serkan; Aydınlı, AtillaFormation of Ge nanocrystals in SiNx matrices has been studied using plasma enhanced chemical vapor deposition in both as deposited samples as well as in post-vacuum annealed samples. Low temperature and short duration anneals in vacuum resulted in Ge nanocrystals whereas prolonged anneals at higher temperatures resulted in Ge nanocrystals accompanied with SiGe formation at the SiNx/Si interface. Raman Scattering Spectroscopy was extensively used to track the formation of various phonon modes during the diffusion of Ge through SiNx and into the Si substrate. (C) 2006 Published by Elsevier Ltd.Öğe Influence of surface preparation in resin/enamel interface: A SEM study(Int Amer Assoc Dental Researchi A D R/A A D R, 2002) Sengun, A.; İpekdal, I.; Özer, F.; Yaşar, E.…Öğe (3, 3-Dichloro-1, 4-Diphenyl-2-Azetidinone)(Int Union Crystallography, 1999) Guven, K.; Durlu, T. N.; Kabak, M.; Guner, V.…Öğe (3,3-Dichloro-4-(P-Methoxyphenyl)-1-(P-Chlorophenyl)-2-Azetidinone)(Int Union Crystallography, 1999) Durlu, T. N.; Guven, K.; Kabak, M.; Guner, V.…Öğe Studies of Al-Ti alloys by SEM(2007) Yıldız, K.; Atici, Y.; Keşlioğlu, K.; Vaşar, E.Al-Ti (1, 2 wt. %) alloys were investigated by Scanning Electron Microscopy (SEM). SEM observations and energy-dispersive x-ray analyses (EDX) showed that the phase structure of Al-Ti (1 %) alloy at 165 ?m/s is composed of Al matrix and C, Ni, Fe and Si particles and the Al-Ti (1 %) alloys at 16 and 8 ?m/s have only the Al matrix and C particles, It was also found that the Al-Ti (2 %) form the Al matrix and intermetallic TiAl. © 2007 American Institute of Physics.Öğe Investigation of the properties of the nuclei used on the new generation reactor technology systems (Conference Paper)(2007) Tel, Eyyüp; Şahin, Hacı Mehmet; Yalçin Ş.; Altinok T.; Kaplan, Abdullah; Aydın, AbdullahThe application fields of the fast neutron are Accelerator-Driven subcritical Systems (ADS) for fission energy production and hybrid reactor systems. The technical design hybrid reactor and ADS systems potentialities require the knowledge of a wide range of better data and much effort. Thorium (Th) and Uranium (U) are nuclear fuels in these reactor systems. Lead (Pb), Bismuth (Bi) and Tungsten (IT) are the target nuclei in the ADS reactor systems. The Hartree-Fock (H-F) method with an effective interaction with Skyrme forces is widely used for studying the properties of nuclei such as binding energy, Root Mean Square (RMS) charge radii, mass radii, neutron density, proton density, electromagnetic multipole moments, etc. In this study, by using H-F method with interaction Skyrme RMS charge radii, RMS mass radii, neutron density and proton density were calculated for the 232Th, 238U, 207Pb, 209Bi and 184W isotopes used on the new generation reactor systems. The calculation results of charge radii have been compared with experimental data and obtained other results have been discussed for hybrid and ADS reactor systems.Öğe Calculations of the main free path on neutron emission cross-section for spallation reaction of target and fuel nuclei(2007) Tel, Eyyüp; Kişoğlu, H.Fatih; Topaksu, A.Kayış; Aydın, Abdullah; Kaplan, AbdullahThere are several new technological application fields of fast neutrons such as accelerator-driven incineration/ transmutation of the long-lived radioactive nuclear wastes (in particular transuranium nuclides) to short-lived or stable isotopes by secondary spallation neutrons produced by high-intensity, intermediate-energy, charged-particle beams, prolonged planstary space missions, shielding for particle accelerators. Especially, accelerator driven subcritical systems (ADS) can be used for fission energy production and /or nuclear waste transmutation as well as in the intermediate-energy accelerator driven neutron sources, ions and neutrons with energies beyond 20 MeV, the upper limit of exiting data files that produced for fusion and fission applications. In these systems, the neutron scattering cross sections and emission differential data are very important for reactor neutronics calculations. The transition rate calculation involves the introduction of the parameter of mean free path determines the mean free path of the nucleon in the nuclear matter. This parameter allows an increase in mean free path, with simulation of effect, which is not considered in the calculations, such as conservation of parity and angular momentum in intra nuclear transitions. In this study, we have investigated the multiple pre-equilibrium matrix element constant from internal transition for Uranium, Thorium, (n,xn) neutron emission spectra. The neutron-emission spectra produced by (n,xn) reactions on nuclei of some target (for spallation) have been calculated. In the calculations, we have used the geometry dependent hybrid model and the cascade exciton model including the effects of the pre-equilibrium. The pre-equilibrium direct effects have been examined by using full exciton model. All calculated results have been compared with the experimental data. The obtained results have been discussed and compared with the available experimental data and found agreement with each other.
