WoS İndeksli Yayınlar Koleksiyonu
Permanent URI for this collectionhttps://hdl.handle.net/20.500.12416/8653
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Article Diffraction in Time of Matter Waves Located in a Confined Region(Springer Heidelberg, 2022) Umul, Yusuf Z.The process of diffraction in time of a standing matter wave is studied. This case occurs generally when a quantum particle is confined in a trap or infinite potential well. First of all, the wave-function of a classical time diffracted matter wave is studied by considering a separation of the Fresnel function in terms of geometrical optics and diffracted waves. The behavior of the matter wave which is the counterpart of a geometrical optics field is investigated. Then a confined particle in a one-dimensional infinite potential well is taken into account. One of the walls of the trap is remained at an initial time and the process of diffraction in time is formulated by using the information, obtained from the geometrical optics fields. Some numerical results are given. This paper proposes two original approaches. The first one is the application of the optical diffraction theory to quantum physics. This is the separation of the scattered field into geometric optics and diffracted wave components. The second novelty is the addition of the effects of both of the traveling waves, which compose the standing wave, to the scattering integral.Article Citation - WoS: 3Citation - Scopus: 3Diffraction of Electromagnetic Waves by an Anomalously Transmitting Metasurface Half-Plane in Anisotropic Plasma(Elsevier Gmbh, 2020) Umul, Yusuf Z.The paper deals with the scattering of magnetic polarized electromagnetic plane waves by a anomalously transmitting metasurface half-plane, located in anisotropic plasma. Such a medium occurs for cold magnetized plasma, in which a static magnetic field exists. In this case the permittivity of the medium is expressed as a tensor, the elements of which are functions of the magnetostatic field, electron's mass and charge and angular frequency of the plasma. The metasurface half-plane transmits part of the incoming electromagnetic wave with a different angle from the angle of incidence, absorbing the remaining part. First of all, we will obtain the scattered geometric optics wave by subtracting the incident field from the total geometric optics wave. Then the kernel of a physical optics type scattering integral will be constructed with the aid of the integral theory of diffraction. The uniform diffracted magnetic field will be obtained from the physical optics integral. The total magnetic field will be evaluated as a sum of the total geometric optics and diffracted waves. The behaviours of the derived fields will be analyzed numerically.Article Comparison of Diffraction Methods for Lunar Occultations(Elsevier Gmbh, 2020) Umul, Yusuf Z.The only analytical method, which is used for the mathematical analysis of lunar occultations, is the Fresnel diffraction. The Fresnel integral is derived from the diffraction integral of Kirchhoff under some approximations. This paper aims to compare this method with the exact solution of Sommerfeld, which is obtained for a perfect electric conductor half-plane. The geometrical optics and diffracted fields are expressed separately. Numerical simulations are given for the comparison of two different total and diffracted waves.Editorial Citation - WoS: 1Citation - Scopus: 1Reply To the "a Comment on "the Photon Momentum(Elsevier Gmbh, Urban & Fischer verlag, 2014) Umul, Yusuf Z.Correction Comment on "a Survey of the New Proposal About the Photon Momentum" (Vol 148, Pg 342, 2017)(Elsevier Gmbh, Urban & Fischer verlag, 2018) Umul, Yusuf Z.Article Citation - WoS: 7Citation - Scopus: 9Rubinowicz Transform of the Mtpo Surface Integrals(Elsevier Science Bv, 2008) Umul, Yusuf Z.The surface integral of the modified theory of physical optics is reduced to a line integral by using the Rubinowicz transform for the incident scattered fields by an arbitrary aperture in a black surface. The integral theorem of Kirchhoff is applied to the scattering geometry and the diffracted fields are expressed in terms of a line integral along the contour of the diffracting edge. (C) 2008 Elsevier B.V. All rights reserved.Article Citation - WoS: 2Citation - Scopus: 2Scattering of a Bessel Beam by a Resistive Disc(Elsevier Gmbh, Urban & Fischer verlag, 2017) Umul, Yusuf Z.Bessel beam has two important advantages that make it preferable for the illumination process of biological samples in microscopy. These are the properties of non-diffraction and self-healing. In this paper, the interaction of the zeroth order Bessel beam with a resistive disc, which models a cell or tissue, is investigated by using the uniform geometrical theory of diffraction. The geometrical optics and diffracted waves are evaluated. The scattering characteristics of the beam and the property of self-healing are studied numerically for different values of the surface resistivity. (C) 2016 Elsevier GmbH. All rights reserved.Article Citation - WoS: 1Citation - Scopus: 1The Relation Between Wave Vector and Momentum in Quantum Mechanics(Elsevier Gmbh, 2016) Umul, Yusuf Z.The fundamental relation of quantum mechanics, which correlates the momentum of a quantum particle to the wave vector of the matter wave, is re-interpreted. The wave vector, in the relation, is formulized as the integration of it along the angular coordinates for two and three dimensional cases. Various evaluations of the wave vector are performed for different types of waves and the results are discussed. Also the edge diffracted fields are considered according to the new interpretation. (C) 2016 Elsevier GmbH. All rights reserved.Article Citation - WoS: 15Citation - Scopus: 15Diffraction of Waves by a Resistive Half-Plane(Elsevier Science Bv, 2014) Umul, Yusuf Z.The scattered waves by a resistive half-plane are investigated with defining reflection and transmission coefficients for the diffracted waves. The coefficients are determined according to suitable conditions that are derived from the boundary conditions and the limiting cases of the reflection and transmission coefficients of the geometrical optics fields. The resultant field expressions are examined and compared with the literature numerically. (C) 2014 Elsevier By All rights reserved.Article Citation - WoS: 3Citation - Scopus: 4The Physical Optics Integral on the Scatterer's Unlit Surface(Elsevier Gmbh, 2014) Umul, Yusuf Z.The scattering integrals of the modified theory of physical optics are redefined according to the illuminated and unlit surfaces of the scattering object. With this aim the canonical problem of wedge diffraction is taken into account. It is shown that the new scattering integral contain two geometrical optics and diffracted fields. One of the geometrical optics waves is the reflected field component that propagates in the real space. The other one transmits to an imaginary space through the scattering surface and does not have any influence in the real space. The diffracted waves exist in the real space and satisfy the related boundary condition on the scattering surfaces. The resultant field expressions are compared with the exact series solution of the problem numerically. (C) 2014 Elsevier GmbH. All rights reserved.