Relativistic mask method for electron momentum distributions after ionization of hydrogen-like ions in strong laser fields

Wavefunction-splitting or mask method, widely used in the non-relativistic calculations of the photoelectron angular distributions, is extended to the relativistic domain within the dipole approximation. Since the closed-form expressions for the relativistic Volkov states are not available within the dipole approximation, we build such states numerically solving a single second-order differential equation. We calculate the photoelectron energy spectra and angular distributions for highly charged ions under different ionization regimes with both the direct and the relativistic mask methods. We show that the relativistic mask method works very well and reproduces the electron energy and angular distributions calculated by the direct method in the energy range where both methods can be used. On the other hand, the relativistic mask method can be applied for longer laser pulses and/or higher photoelectron energies where the direct method may have difficulties

On some of the peculiarities of propagation of an elastic wave through a gradient transversely isotropic layer

© 2014 IEEE. The problem of diffraction of a plane elastic wave by a gradient transversely isotropic layer is studied. The diffraction problem is reduced to a boundary value problem for the layer. The grid method is used for solving the resulting boundary value problem. Diffraction of a plane longitudinal wave by the layer is considered. Peculiarities of the gain-frequency and the gain-angle characteristics of density of a normal component of an energy flow of a passed longitudinal wave are studied numerically

Diffraction of a plane elastic wave by a gradient transversely isotropic layer

The problem of diffraction of a plane elastic wave by a gradient transversely isotropic layer is considered. Using the method of overdetermined boundary value problem in combination with the Fourier transform method, the system of ordinary differential equations of the second order with boundary conditions of the third type is obtained which is solved by the grid method. Results of calculations obtained using the above-mentioned technique for the case of piecewise linear profiles for the Young modulus of the layer are given. © 2013 Anastasiia Anufrieva and Dmitrii Tumakov

On peculiarities of propagation of a plane elastic wave through a gradient anisotropic layer

© 2015 Anastasiia Anufrieva et al. The problem of diffraction of a plane elastic wave by an anisotropic layer is studied. The diffraction problem is reduced to a boundary value problem for the layer. The grid method is used for solving the resulting boundary value problem. The diffraction of a plane longitudinal wave by the layer is considered. Some peculiarities of the gain-frequency and the gain-angle characteristics of a normal component of an energy flow of a passed longitudinal wave are numerically studied

Peculiarities of propagation of a plane elastic wave through a gradient layer

The problem of diffraction of a plane elastic wave by a gradient in the transverse direction layer is studied. The diffraction problem is reduced to a boundary value problem for the layer. The grid method is used for solving the resulting boundary value problem. Considered is diffraction of a plane longitudinal wave by the layer. The layer is composed of the following materials: plexiglas, steel as well as their linear combinations. Peculiarities of an amplitude-frequency characteristic of density of a normal component of an energy flow of a passed longitudinal wave are studied numerically. © 2013 IEEE

On electrical characteristics of comb-shaped microstrip antennas

© 2017 IEEE.The microstrip antennas with symmetrical comb-shaped radiator are considered. The influence of depth of the cuts on main electrical characteristics of four- and eight-comb antennas is researched. The resonance frequency, the bandwidth and reflection coefficient are chosen as characteristics. The graphs of unknown dependencies are constructed for the two basic frequencies

Second-Order Accurate Finite-Difference Scheme for Solving the Problem of Elastic Wave Diffraction by the Anisotropic Gradient Layer

© 2018, Pleiades Publishing, Ltd. The boundary value problem for the Lame equations for the problem of elastic wave diffraction by an anisotropic layer with continuously varying elastic parameters is considered. The original problem is reduced to the boundary value problem for a system of ordinary differential equations of the given form. The finite-difference scheme is obtained by the method of approximation of integral identities. The theorem is proved that the error of approximation of the solution has a second order of accuracy for sufficiently continuous values of the elements of the elasticity tensor. Numerical results confirming theoretical conclusions are given

Approximation error of one finite-difference scheme for the problem of diffraction by a gradient layer

© 2017 Pushpa Publishing House, Allahabad, India.The finite-difference scheme, constructed by the method of approximating an integral identity, is considered for a boundary value problem involving the one-dimensional Lame equations, which describe the problem of diffraction by gradient isotropic and transversal-isotropic layers. We prove that the finite-difference scheme is second-order accurate and can be recommended for use in solving the Lame equations with continuous coefficients