Digital Commons Network^™

Testing Deca-Tev Unified Compositeness At The 4 Tev \Mu_+\Mu_-Colliders, Vasily V. Kabachenko, Yury F. Pirogov

Turkish Journal of Physics

In the framework of the unified compositeness of leptons, quarks and Higgs bosons, the hidden local symmetry $\hat H_{loc}=SU(2)_L\times U(1)_Y$ with the heavy composite vector bosons, in addition to the SM gauge bosons, is briefly described. Supplementary hypothesis of the vector boson dominance (VBD) of the SM gauge interactions is considered. It is argued that this should produce the universal dominant residual interactions of the SM composite particles, i.e., all of the fermions and Higgs bosons. Restrictions on the universal residual fermion-fermion, fermion-boson and boson-boson interactions due to the VBD are investigated. Manifestations of the residual interactions at the 4~TeV …

Interaction Region And Luminosity Limitations For Thetesla/Hera E/P Collider, R. Brinkmann

Turkish Journal of Physics

No abstract provided.

Secondary Electron Emission And Spacecraft Charging, Neal Nickles, John R. Dennison

All Physics Faculty Publications

Spacecraft charging due to the natural plasma environment found in all orbits is known to produce many of the observed spacecraft anomalies and failures. A primary factor in adverse spacecraft charging is the secondary electron emission of differing materials on the spacecraft. Precipitating electrons and ions from the plasma to spacecraft surfaces can result in varying amounts of charge being released, depending on the secondary electron yield of the materials; this can lead to arcing between surfaces. NASA's Space and Environments Effects (SEE) program has recognized the need to improve their current materials database for modeling spacecraft charging and have …

Gradient Drift Instability Growth Rates From Global-Scale Modeling Of The Polar Ionosphere, Jan Josef Sojka, M. V. Subramanium, L. Zhu, Robert W. Schunk

All Physics Faculty Publications

The winter polar ionosphere, under southward interplanetary magnetic field (IMF) conditions, experiences irregularity development leading to consequences such as scintillation on transionospheric communication links. These irregularities are associated with antisunward convecting polar ionospheric patches. The gradient drift instability (GDI) has been considered a primary candidate for the generation of these irregularities, or at least the long-wavelength energy source of the irregularity-wave cascade process. The Utah State University time-dependent ionospheric model (TDIM) enables the polar cap ionosphere and its patches to be modeled on a large scale in a time-evolving manner. Hence, at each point in space and time, the TDIM …

A Compact Rotating-Mirror Autocorrelator Design For Femtosecond And Picosecond Laserpulses, D. Mark Riffe, A. J. Sabbah

All Physics Faculty Publications

An interferometric rapid-scanning autocorrelator employing two antiparallel rotating mirrors in a variable arm is optimized for maximum optical path difference as a function of the separation of the two rotating mirrors. A very compact design (mirror separation≈mirror diameter) is possible without a reduction in the maximum pulse width that can be measured.

Evolution Of Secondary Electron Emission Characteristics Of Spacecraft Surfaces: Importance To Spacecraft Charging, R. E. Davies, John R. Dennison

All Physics Faculty Publications

Secondary electron emission (SEE) plays a key role in spacecraft charging [Garrett, 1981; Frooninckx and Sojka, 1992] . As a result, spacecraft charging codes require knowledge of the SEE characteristics of various materials in order to predict vehicle potentials in various orbital environments [Katz, et. al., 1986]. Because SEE is a surface phenomenon, occurring in the first few atomic layers of a material, the SEE characteristics of a given surface are extremely sensitive to changes in surface condition—e.g., the addition or removal of surface contaminants, or changes in surface morphology. That spacecraft surfaces can and generally do undergo significant evolution …

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, …

Kinetics Of Random-Field Induced Domains In The Two-Dimensional Ising Antiferromagnet Rb2co0.85mg0.15f4, Christian Binek

Christian Binek Publications

The previous kinetics of the two-dimensional diluted Ising antiferromagnet Rb2Co0.85Mg0.15F4 is studied via the temporal relaxation of the field-induced magnetization after field cooling (FC) and zero-field cooling (ZFC), respectively, to T < TN = 75.2K. After FC different non-exponential decay laws indicate a crossover from domain reorientation to wall rearrangement at decreasing T. After ZFC rapidly saturating magnetization of naturally grown domain walls precedes the slow random-field-controlled disordering process.

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.

Structural Defects And Electrical Properties Of Extruded Samples Of Bi_{85}Sb_{15} Solid Solutions, Farkhad Samedov, Mail Tagiev

Turkish Journal of Physics

The effect of 5 hours annealing in vacuum $\sim 10^{-3} Pa$ at $503 K$ on the electroconductivity $(\sigma)$, the coefficient of thermoelectric power $(\alpha)$ and the Hall coefficient $(R_x)$ for extruded samples of $Bi_{85}Sb_{15}$ has been investigated in the temperature range from $\sim 77 K$ up to $\sim 300 K$. The samples were taken with a different concentration of $Pb$ (lead) up to $\sim 0.1 a.w \%$. The anisotropy of electrical properties of these samples was also studied in the temperature range between $77 K$ and $300 K$ and in the presence of magnetic field up to $\sim 74 \times …

An Analysis Of The Variation In Calculated Confined-State Energies Using Different Envelope-Function Models, Beşire Gönül

Turkish Journal of Physics

We investigate different formulations of the envelope-function method and show that the accuracy of the calculated zone-centre confinement energies can be calculated by means of bulk band structure. We show how coupling to the conduction and spin-split-off bands can decrease the light-hole zone-centre confinement energies and lead to significant differences in the calculated subband dispersion.

Effect Of Neutron Irradiation On Carriers Removel Rates In N-Si, M.S. Yunusov, M. Karimov, B.L. Oksengendler, M.A. Zhalelov

Turkish Journal of Physics

Carrier removal rate in $n-Si \langle P, Rh \rangle$ with different doping rhodium concentrations were investigated under fast neutrons irradiation. It is shown that the rate of carrier removal increases with phosphorus atom concentration but decreases with rhodium atom concentration. Theoretical analysis on the base of kinetic equations has shown that standard scheme of quasichemical reactions taking into account the interaction between rhodium atoms, vacancies and self interstitial atoms could not explain the results of experiment. Therefore a new model based on the use of radiation to increase the barrier between regions of fluctuating impurity concentration has been proposed.

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.

Magnetic Diffuse Scattering In The Frustrated Square Lattice, Ali Bayri, Funda Ersoy Atalay, Hüseyin Gencer

Turkish Journal of Physics

Some of the first transition metal alloys show first order antiferromagnetic phase transition as a function of alloy concentration [1-5]. The antiferromagnetism of materials can be classified into three different class: type I, type II and type III. Although the neutron diffraction studies give information about the type of magnetism, they do not show the fluctuations of magnetic moment from the original direction. So in order to have some information about this fluctuations one must perform the magnetic diffuse scattering. Recently, we proposed that the square lattice may have a double-Q structure as well as single-Q [6]. We showed that …

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. …

Solution Of Optic Reconstructive Problem Considering Registered Signal Velocity, A.A. Aliverdiev, M.G. Karimov

Turkish Journal of Physics

A solution to the tomographic problem of dynamic reconstruction of a processes, the rate of which is comparable with the velocity of the registered signal is presented. The obtained data can be used both for theoretical and applied tomography.

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 …

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.

Comparison Of Metallicities Adopted For The Synthetic Ubv Photometry With Those Evaluated By Means Of Rgu Photometry, S. Karaali̇, S. Güngör, Y. Karataş

Turkish Journal of Physics

Comparison of metallicities adopted for synthetic UBV photometry with those evaluated by means of RGU photometry for 92 stars is presented. The agreement is only for zero metallicity. The discrepancy increases to low metallicities which cover Intermediate Population II and Population II main-sequence stars. U-G and G-R colour indices are transformed from UBV synthetic data and do not include any observational error. Therefore, the disagreement may originate from a systematic error in the metallicity calibration of relatively metal-poor stars in RGU photometry. Keywords: photometry - stars : abundances - metal-poor.

Magnetic Domain Structures In As-Quenched And Annealed Fe_{78}B_{13}Si_9 Metallic Glass Ribbons, Yücel Bi̇rol

Turkish Journal of Physics

Among various soft magnetic materials, ferromagnetic glasses are superior to their crystalline counterparts as they possess no magnetocrystalline anisotropy owing to a non-crystalline structure. However, ferromagnetic glasses carry residual stresses and thus anisotropies of magnetostrictive origin in the as-quenched state. These stresses have an adverse effect on the magnetic softness and should be relieved in order to improve magnetic performance, particularly in magnetostrictive alloys. In the present work, the domain structures of Fe$_{78}$B$_{13}$Si$_9$ metallic glass, a highly magnetostrictive alloy, are characterized in the as-quenched and annealed states. The annealing treatments were carried out over a wide temperature range extending from …

Economic Analysis And Comparison Of Two Solar Energy Systems With Domestic Water Heating Systems, R. Kayali

Turkish Journal of Physics

In this work, an economic analysis of different types of thermosiphons and geysers and flat plate collectors and solar ponds employeed in conventional solar energy systems used in houses is analized and the results obtained for these systems are compared with each other. These comparisons show that when the inflation rate is 50\% or less solar energy systems are more economical than the other conventional systems, except for conventional systems in which solid fuels are used. If the calculations are done assuming that the consumer credit interest rate varies between 55-70\%, it is seen that solar energy systems will only …

Domain Structures Of Epitaxial Perovskite Ferroelectric Films: Part I. Theory, S. Pamir Alpay, Alexander L. Roytburd

Turkish Journal of Physics

Possible equilibrium domain structures due to elastic interactions between the film and the substrate as a result of a cubic-tetragonal transformation observed in epitaxial perovskite ferroelectric films are analyzed. Domain structures are compared in terms of their elastic energies. The formation of both two- and three-domain states is taken into account. Maps which shows domain stability regions are developed in coordinates of misfit strain and tetragonality of the lattice of the ferroelectric phase.

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 …

Crystal Data For A_3b_5c_9-Type Ternary Compounds, Hüsnü Özkan, Nizami Gasanly, İbrahim Yilmaz, Ali Çulfaz, Vyaceslav Nagiev

Turkish Journal of Physics

X-ray powder diffraction data were obtained for Cu$_3$Ga$_5$Se$_9$, Cu$_3$In$_5$Se$_9$, Cu$_3$In$_5$Te$_9$, Ag$_3$In$_5$S$_9$, Ag$_3$Ga$_5$S$_9$, Ag$_3$In$_5$Se$_9$, and Ag$_3$Ga$_5$Te$_9$ ternary compounds. The data indicate that these compounds crystallize in orthorhombic, monoclinic, orthorhombic, monoclinic, tetragonal, tetragonal, and orthorhombic systems, respectively.

Observation Of Events At Very High Q^2 In E^+P Collisions At Hera, A. Wagner

Turkish Journal of Physics

Data collected at the $e^+p$ collider HERA at DESY by the experiments H1 and ZEUS have allowed to probe a previously inaccessible domain of very large $Q^2$ in deep-inelastic $ep$ scattering. For $Q^2 > 15000 GeV^2$ both experiments see more events than expected assuming the Standard Model of deep-inelastic scattering. In this report the observed events, the theoretical expectations and their comparison are discussed.

Progess In Photon Colliders, Valery Telnov

Turkish Journal of Physics

Last two years were very important in history of a photon colliders. This option is included now in conceptual design reports of the NLC, JLC and TESLA/SBLC projects. All the designs foresee two interaction regions: one for e^+e^- and the second for \gamma\gamma, \gamma e and e^-e^- collisions. This paper is focused on three aspects: 1) arguments for photon colliders; 2) parameters of current projects; 3) ultimate luminosities and energies, new ideas. Recent studies have shown that the main collision effect - coherent pair creation - is suppressed at photon colliders with the energy (2E $

High Luminosity Muon Collider Studies In The U.S.A., Muzaffer Ataç

Turkish Journal of Physics

Muon colliders as a future collider project in the U.S.A., have attracted many physicists from many institutions in recent years. Workshops and conferences have been held on the subject in the last few years. The studies show that high luminosity circular muon colliders can be built at high luminosities and at high center-of-mass energies. Some aspects of the muon colliders, physics possibilities, background and detector issues will be discussed. Some comparisons between the muon and hadron colliders, and electron-positron colliders, will be made.

Possibility To Measure Polarized Gluon Distribution Via Real Gamma Beam, A. Çeli̇kel

Turkish Journal of Physics

We propose an experiment to measure the polarized gluon and quark distributions in scattering of polarized real $\gamma$ beam on polarized nuclear target.

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.