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K. B. Oganesyan

Publications and source records attributed to K. B. Oganesyan.

25 records · Page 2Linked to original sources
arXiv2017

X-Ray Radiation Generation in Heat Engines Using Electron Cooling

We consider a relativistic quantum heat engine that goes through a thermodynamical cycle consisting of stages involving laser-assisted cooling of electrons and the generation of Xray radiation. Quantum treatment of the processes makes it possible to obtain the necessary condition and the amount of work extracted from the interaction ingredients, as well as the efficiency of the heat engine. We have also found that the efficiency of the relativistic engine is less than the one for the nonrelativistic case for the same momenta. The obtained results set the limits to the cooling, as well as the intensity of X-ray radiation, in the quantum regime of the interaction of electrons with laser fields.

physics.acc-ph↗
arXiv2017

Undulator radiation in the THz range

The experimental device for generation of undulator radiation in terahertz wavelength region by use of undulator on ferromagnets is created. The device is based on a beam of a microtrone with the energy 7.5 MeV. The radiation wavelength is 200 micron. Registered spontaneous radiation has a power of 10 microwatt at a current of a beam 2 mA in a pulse. With the optical resonator, in a mode, the amplification of 6 percent is received, that in some times is more than expected value. This effect is explained as a result of partial coherence of radiation.

physics.acc-ph↗
arXiv2016

Infrared Radiation from Rough Surface

We consider generation of diffusive radiation by a charged particle passing through a random stack of plates in the infrared region. Diffusive radiation originates due to multiple scattering of pseudophotons on the plates. To enhance the radiation intensity one needs to make the scattering more effective. For this goal we suggest to use materials with negative dielectric constant .

physics.acc-ph↗
arXiv2014

Mathematical Modeling of Graphite-to-Diamond Transition

The energetic evaluations of graphite-to-diamond transition by electron irradiation are performed. The heat conduction problem is solved for the diamond synthesis when a pulse-periodic source of energy is located within a graphite cylinder; time dependences of temperature and pressure are found. It is shown, that the temperatures and pressures implemented in graphite are sufficient for graphite-to-diamond transition under electron bombardment.

cond-mat.mtrl-sci↗
arXiv2002

Exact finite-size corrections for the square lattice Ising model with Brascamp-Kunz boundary conditions

Finite-size scaling, finite-size corrections, and boundary effects for critical systems have attracted much attention in recent years. Here we derive exact finite-size corrections for the free energy F and the specific heat C of the critical ferromagnetic Ising model on the M x 2N square lattice with Brascamp-Kunz (BK) boundary conditions [J. Math. Phys. 15, 66 (1974)] and compared such results with those under toroidal boundary conditions. In the limit N \to \infty we obtain the expansion of the free energy for infinitely long strip with BK boundary conditions. Our results are consistent with the conformal field theory prediction for the mixed boundary conditions by Cardy [Nucl. Phys. {\bf B 275}, 200 (1986)] although the definitions of boundary conditions in two cases are different in one side of the long strip.

cond-mat.stat-mech↗
arXiv1999

Exact phase diagrams for an Ising model on a two-layer Bethe lattice

Using an iteration technique, we obtain exact expressions for the free energy and the magnetization of an Ising model on a two - layer Bethe lattice with intralayer coupling constants J1 and J2 for the first and the second layer, respectively, and interlayer coupling constant J3 between the two layers; the Ising spins also couple with external magnetic fields, which are different in the two layers. We obtain exact phase diagrams for the system.

cond-mat.stat-mech↗