Physical Sciences and Mathematics Commons^™

Relativistic Electron In The Field Of Two Coulomb Centers, V.I. Matveev, D.U. Matrasulov, Kh. Yu. Rakhimov

Turkish Journal of Physics

Ground state wave function and the energy term of the relativistic electron moving in the field of two Coulomb centers are calculated analytically by the method of linear combination of atomic orbitals. Obtained analytical formula is applied to the calculation of the critical distance between two heavy nuclei at which energy term reaches the boundary of the lower continuum.

On The One-Loop Yukowa Coupling Beta Function To Order Yg^2 In A General \Alpha Gauge And Its Gauge Indepence, M. Özer

Turkish Journal of Physics

We present the calculation of the one-loop Yukawa coupling beta function to order $Yg^2$ in a general $\alpha$ gauge, where $Y$ and $g$ are Yukawa and gauge couplings. We show explicitly how the gauge parameter $\alpha$ cancels out from the beta - function and demonstrate how some familiar results are obtained from it.

The Milne And The Constant Source Problems For The Fbis Kernel, M.Ç .. Güleçyüz, A. Kaşkaş

Turkish Journal of Physics

Transport solutions to the monoenergetic constant source and the Milne problems for the forward-backward-isotropic scattering (FBIS) kernel are obtained by method of singular expansion modes. The monoenergetic linear transport equation for extremely anisotropic scattering with constant source is reduced to a transport equation with isotropic scattering. The expansion coefficient is obtained in a form involving exact integral equations and determined by the accompanying new boundary conditions and the half-range orthogonality relations. In the zeroth order approximation, the analytical expressions for neutron density and the emergent angular distributions are also obtained as a function of forward scattering.

Topics On The Physics Potential And Detector Aspects Of The Lc-Hera Ep Collider, A. De Roeck

Turkish Journal of Physics

We present a brief account of some physics topics which could be addressed at a collider consisting of the HERA proton ring and the future $e^+e^-$ Linear Collider. A few experimental aspects are also discussed.

Physics At Future Ep, \Gammap (Linac-Ring) And \Mup Colliders, Ilya F. Ginzburg

Turkish Journal of Physics

The physical problems for the enumerated colliders are discussed. It is taken into account that all these machines can work only after corresponding parental colliders.

Some Physical Problems For Photon Colliders, Ilya F. Ginzburg

Turkish Journal of Physics

Higgs hunting at different colliders is discussed with new possibilities related to photon colliders are discussed. Brief review of discovery potential for new physics is presented.

Physics At Hera+Lc Based \Gammap Colliders, Z. Z. Aydin

Turkish Journal of Physics

In this proceeding I discuss the proposal of constructing a $\gamma p$ collider at DESY based on a Linac-Ring type $ep$ machine, the HERA+LC. A high energy $\gamma$ beam for this collider is produced by the Compton back-scattering of laser photons off the electron beam from the linear accelerator. Using the parameters of the proton ring of HERA and those of the proposed linear $e^{+}e^{-}$ colliders (LC, specifically TESLA, CLIC or Linac1) we expect a luminosity of $L_{\gamma p} =(1-2)\times 10^{31} cm^{-2} s^{-1}$, due to a reasonable improvement of the proton beam. We examine the physics research program for the …

Effect Of Deposition Conditions On Composition Of Rf-Sputtered Bi-Sr-Ca-Cu-O Thin Films, Ayhan Güldeste

Turkish Journal of Physics

The effect of rf-magnetron sputtering conditions on as-deposited film composition using a stoichiometric Bi_2Sr_2CaCu_2O_y (Bi-2212) target was investigated in an on-axis configuration, as the stoichiometrical control of the film is the most important parameter for the proper study of film characteristics. It was found that substrate target distance up to 55-60 mm may provide a film composition close to the target composition. The sputtering chamber pressure effecting film composition, especially in respect of Bi, is an important parameter which needs very pracise control. Bi ratio in the deposited films increases with increasing Ar pressure while Sr and Ca are not …

A Lattice Model For Computing The Transmissivity Of The Cornea And Sclera, David B. Ameen, Marilyn F. Bishop, Tom Mcmullen

Physics Publications

Abstract

The method of photonic band structure is used to calculate the frequencies of light that propagate in lattice models of the cornea and sclera of the mammalian eye, providing an explanation for transparency in the cornea that first properly accounts for multiple scattering of light. Each eye tissue is modeled as an ordered array of collagen rods, and photonic band structure methods are used to solve Maxwell's equations exactly for these models, a procedure that automatically effectively includes all orders of multiple scattering. These calculations show that the dispersion relation for the cornea is linear in the visible range, …

Searching For Leptoquarks At Gamma-P Colliders, S. Atağ

Turkish Journal of Physics

A study for single and pair production of scalar and vector leptoquarks in the collision of high energy $\gamma $ and proton beams is presented. It is shown that future $\gamma p$ colliders may play a complementary role to investigate unknown leptoquark properties.

Study Of The Total Reaction Cross Section Of 17.0 Mev=N 132 Xe + 238 U Heavy Ion Interactions, J.J. Baluch, E.U. Khan, M.S. Zafar, I.E. Qureshi

Turkish Journal of Physics

We have studied heavy ion nuclear interactions of 17.0 $MeV/N$ $^{132}Xe+^{238}U$ using muscovite mica as Solid State Nuclear Track Detector (SSNTD). Experimental reaction cross section has been determined by two independent methods. Theoretical reaction cross section has been calculated by a classical formula taking into account the energy dependence of the nuclear radius parameter. The cross section determined in the present work has been compared with those at two other energies for the same reaction.

Resonance Production Of New Resonances At Ep And \Gamma P Colliders, A. Çeli̇kel And M. Kantar

Turkish Journal of Physics

We study the resonance production of new particles predicted by preonic models at Linac-Ring type $ep$ and $\gamma p$ colliders. It is shown that these machines will allow to investigate the new particles with masses up to few TeV scale.

The Structure Of Liquid Alloys With Chemical Short Range Order, Serap Dalgiç, Seyfettin Dalgiç, Mehmet Tomak

Turkish Journal of Physics

We present a study of the structural properties of liquid binary alloys with chemical short range order starting from the effective interatomic pair potentials. The interatomic pair potentials are derived using the second order pseudopotential theory and the static structure is obtained using the modified hypernetted chain approximation. The partial structure factors $S_{ij}(q)$ and the concentration - fluctuation structure factor $S_{cc}(q)$ are calculated to analize the ordering tendencies in a binary alloy. In this work, liquid Li-Mg alloy is studied as a test case. The agreement between theory and experiment is quite good. We conclude that the structural properties of …

Influence Of Thermal Conductive Material On The Activation Energy Of Amorphous Silicon Thin Films, Sevilay Uğur, Merih Seri̇n

Turkish Journal of Physics

The activation energy of amorphous silicon thin films are usually measured by placing the thin film sample on a heating surface and monitoring the change in the dark conductivity as a function of temperature. The most widely used devices for temperature measurements are surface thermometers and thermocouples. Sensors such as surface thermometers or thermocouples simply measure temperature by reaching an equilibrium state with the measured environment. If the heat conduction to the sensor somehow is obscured by several reasons (sensors having a much larger dimensions than the thin film or not having proper vacuum) different thermal conduction to the sensor …

Search For Supersymmetry At \Gammap - Colliders, A. U. Yilmazer

Turkish Journal of Physics

We discuss the possibility of searching supersymmetry at TeV scale $\gamma p$ colliders proposed recently. Theoretical predictions are derived within the framework of minimal supersymmetric standard model (MSSM) with R-parity conservation. Productions of squarks, gluinos, charginos and neutralinos through the processes $\gamma p\rightarrow\tilde{q}\tilde{w}X$, $\gamma p\rightarrow\tilde{q}\tilde{g}X$, $\gamma p\rightarrow\tilde{q}\tilde{\gamma}X$ (or $\tilde{q}\tilde{z}$) and $\gamma p\rightarrow\tilde{q}\tilde{q}^*X$ are considered. Cross sections for different initial beam polarizations are calculated and it is shown that polarization asymmetries are sensitive to the particle masses. Discovery mass limits of the superpartners are tabulated for various $\gamma p$ colliders at different center of mass energies. The results are compared with …

Discovery Limits For New Resonances At Ep And \Gammap Colliders, M. Kantar

Turkish Journal of Physics

We study the resonance production of new particles at Linac-Ring type $ep$ and $\gamma p$ colliders.

Heavy Quark Production At \Gammap Colliders, O. Çakir, M. Yilmaz

Turkish Journal of Physics

Heavy quark pair production at $\gamma p$ colliders is discussed. It is shown that the numbers of $t\bar{t}$ pairs are sufficiently large for investigation of the top quark properties in detail.

Isotope Effect And Phonon Softening In Superconducting Borocarbides And Boronitrides, Tuğrul Haki̇oğlu, Valery A. Ivanov

Turkish Journal of Physics

The isotope effect in the recently disvovered class o superconductors LuNi_2B_2C and La_3Ni_2B_2N_3 is investigated in the context of electron-squezed phonon interaction renormalizing the Ni-d electron-electron correlations. Squeezed phonon mode originates from the anharmonic character of the tetragonal Ni-B structure and is polarized in the vortical direction to the Ni layers. The isotope effect arises as a result of the zero point motion of the Ni-Ni d-electron hopping amplitude dominantly due to this vertical phonon mode. Within this model the isotope exponent is calculated to be \alpha_B \leq 0.20 as compared to the recently found experimental value \alpha_B^{exp} = 0.27 …

Flavour Violating \Tau-Decays In Magnetic Interaction And E_6 Models, A.T. Alan, Z.Z. Aydin And S. Sultansoy

Turkish Journal of Physics

In the view of future c-\tau-factories, we report an analysis of the rare decays of the \tau lepton via \tau \to \mu e \overline{e}, \tau \to e \mu \overline{\mu}, \tau \to \mu \mu \overline{\mu} and \tau \to ee \overline{e} in the two models, i.e., in Barut's magnetic interaction model (MIM) and in an E_6 model proposed by Gürsey and his collaborators. The energy distributions of one of the final leptons are given for both models. Numerical estimates reveal that these decays can be as large as 10^{-6}, which may be observed in LEP experiments or at other c-\tau factories.

Infrared Diode Laser Spectrometer For The Study Of Jet Cooled Gases, Anthony Bednar, Eric Barnett, Candace Lindsay, Trey Heath, Philip Williams, Mark Draganjac, Scott W. Reeve

Journal of the Arkansas Academy of Science

We have constructed a tunable, high resolution, infrared diode laser spectrometer and combined it with a pulsed supersonic jet expansion. A modified version of the Perry multipass cell has been incorporated into the spectrometer to increase the effective absorption path length. Performance capabilities of the spectrometer are evaluated by examining ro-vibrational spectra for the carbon monoxide molecule in the five micron region of the infrared. From these measurements, an instrumental absorption sensitivity is determined. Finally, since one of our immediate goals is the infrared study of jet cooled transition metal carbonyls, we present high resolution data obtained by entraining the …

Applying Binomial Statistics To Weighted Monte Carlo, Sue Ellen Mccloskey, William C. Hall, Wilfred J. Braithwaite

Journal of the Arkansas Academy of Science

Weighted Monte Carlo calculations requiring a uniform sampling of the problem-space can suffer from diminished statistical significance because many, if not most, of the randomly-chosen sampling points contribute only slightly to the desired result. Their contribution is reduced in size due the variable-size of the weighting terms. In contrast, none of the randomly-chosen points which are favored by variable size weighting terms will have their statistical significance enhanced beyond that of just one random point in the Monte Carlo sampling. A Monte Carlo analysis was used in earlier work to verify both Gauss' Law and Newton's Shell Theorem. Both examples …

Surface Morphology Of Laser-Superheated Pb(111) And Pb(100), Z. H. Zhang, Bo Lin, X. L. Zeng, H. E. Elsayed-Ali

Electrical & Computer Engineering Faculty Publications

The surface step density on the vicinal Pb(111) and the surface vacancy density on Pb(100) after laser superheating and melting are investigated using reflection high-energy electron diffraction. With ∼100-ps laser pulses, Pb(111) surface superheating does not significantly change the density of the steps and step-edge roughness. However, after laser surface melting, the average terrace width and the string length at the step edge become as large as those at room temperature. The average terrace width at 573 K changes from 38±15 to 64±19 Å after laser surface melting, while the average string length at the step edge changes from 90±14 …

Symmetry Of C_{60} And A Force Constant Model For Vibrational Modes, Ramazan Koç, Hayriye Tütüncüler

Turkish Journal of Physics

A force-constant model for the vibrational modes in $C_{60}$ is presented. The Keating type potential is adopted for calculating the dynamical matrix. Using symmetries of the molecule, the dynamical matrix which yields the vibrational modes is block-diagonalized. We summarize the role of group theory in specifying the vibrational modes. The results are in excellent agreement with experiments. The effect of bond-stretching force constants on the vibrational modes will be presented.

Q1d-Polarons In Rigid Boundary Cylindrical Wires: "Mixed-Coupling Approximation", R. T. Senger And A. Erçelebi̇

Turkish Journal of Physics

We consider the interaction of a confined electron with bulk polar-optical phonons in a cylindrical quantum well wire with infinite boundary potential. Expressions for the polaron self energy and mass are derived within a composite variational scheme consisting of a strong-coupling characterization imposed in the lateral directions and a weak-coupling LLP-counterpart structured along the length of the wire. The formulation is seen to be rather commendable and yields a sensible description of the Q1D-polaron in thin wires of weak or intermediate electron-phonon coupling strengths.

Singlet Axial Current Form Factor In The Chiral Solitonic Bag Model With Massive Quarks, N. Karagöz

Turkish Journal of Physics

Singlet axial current form factor $g_A^0$ is calculated as a function of bag radius in the two flavor chiral solitonic bag model with unequal quark masses. The value of $g_A^0$ near 1 fm is sufficiently small.

Current-Voltage Characteristics And Photoresponse Of Metal Metal Devices, K. Singh, S.N.A. Hammond

Turkish Journal of Physics

Thin films (35 \AA) of $Al_2O_3$ on glass slides have been used for the fabrication of $Al/Al_2O_3/Al, Ag/Al_2O_3/Al$ and $Cu/Al_2O_3/Al$ devices. The room temperature current-voltage characteristics and the dependence of current densities of these devices at various wavelength $(\lambda)$ of light were measured. The results obtained on current density and photocurrent show that $Al_2O_3$ films have the potential for wider applications like antireflective coatings or treatments in photovoltaic devices, transparent insulation materials, and optical trapping surfaces in many electronic devices.

Study Of Kinetic Coefficients Of (Gete)_{1-X} - (Ga_2te_3)_X Solid Solutions, M.H. Akperov, T. Atalay, H. Aşkin, A.M. Erer

Turkish Journal of Physics

In this study, such kinetic cparametres as thermoelectro motor force (thermo e.m.f), electrical coductivity, heat conductivity, Hall and Nernst-Ettingshausen coeficients are investigated, as a function of chemical composition of $(GeTe)_{1-x}-(Ga_2Te_3)_x$ and temperature, by physicochemical methods and x-rays analysis. The kinetic parameters $(GeTe)_{1-x}-(Ga_2Te_3)_x$ solid solutions are investigated between x=0 and 0,015 and between 77 and 900 K. Adding of $Ga_2Te_3$ to GeTe reduces the phase transition temperature of $\beta$-GeTe to $\alpha$-GeTe. It is observed that in the region of solid solution the rhombohedral modification of GeTe are protected. Doping of GeTe with $Ga_2Te_3$ does not affect the kinetic parameters of GeTe. …

Influence Of Medium On Generation Of Localized Charges In Beo By The Exposure Of The Electrical Discharge In Air And Oxygen, M.M. Aliev

Turkish Journal of Physics

The EPR-method is used to investigate the regularity of the formation of paramagnetic $ F^+$- and $ V^-$ centers (PC) in BeO which are generated by barrier electrical discharge (ED) in air and oxygen under reduced pressure. It was determined that, at different powers of discharge or parameters E/P, the maximums of kinetic curves of PC- accumulation in oxygen in comparison with air plasma forming medium are changed with resspect to both their value and position, depending on the interaction of oxygen atoms and ions $O, O^+, O^-, O^+_2, O^-_2,\ldots)$ with BeO surface. These exposures resulted in decreasing rate of …

Shallow Donors In A Quantum Well Wire; Electric Field And Geometrical Effects, M. Ulaş, H. Akbaş, M. Tomak

Turkish Journal of Physics

Subband and shallow donor binding energies are calculated. The emphasis is given on the electric field effects for wires of different shapes. It is shown that the donor binding energy is sensitive to the interplay of the electric field and geometrical effects.

Nanosecond Duration Broadband Luminescence Of Quartz Glasses, Maruf A. Kasymdzhanov, Pulat K. Khabibullaev, Saidislam S. Kurbanov

Turkish Journal of Physics

The results of investigations of luminescence, excited by radiations of $N_2$- and $Nd^{3+}$: YAG-lasers ($\lambda = 337 nm, \lambda = 532 nm$) in high purity quartz glasses are reported. The luminescence has broad spectrum (350-850 nm) and very short duration (1-20 ns).