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Alexander Ayriyan

Publications and source records attributed to Alexander Ayriyan.

21 records · Page 2Linked to original sources

Algorithm and Simulation of Heat Conduction Process for Design of a Thin Multilayer Technical Device

A model of a multilayer device with non-trivial geometrical structure and nonlinear dependencies of thermodynamic material properties at cryogenic temperatures is suggested. A considered device, called cryogenic cell, is intended for use in multicharged ion sources for pulse injection of gaseous species into ionization space of ion sources. The main requirement for the cryogenic cell operation is the permanent opening and closing for gaseous species injection in a millisecond range, while cell closing is provided by freezing of the gaseous specie at the outer surface of the cell and the cell opening - by the corresponding pulse heating of the cell surface up to definite temperature. The thermal behaviour of the device in a millisecond time range is simulated. The algorithm for solving the non-stationary heat conduction problem with a time-dependent periodical heating source is suggested. The algorithm is based on finite difference explicit-implicit method. The OpenCL realization of the algorithm is discussed. The optimal particular choice of the parameters to provide the required pulse temperature regime of the designed cryogenic cell for the chosen working gas is presented. Based on these results further optimization can be formulated.

physics.comp-ph↗

Bayesian analysis for two-parameter hybrid EoS with high-mass compact star twins

We perform a Bayesian analysis in the basis of a recently developed two-parameter class of hybrid equations of state that allow for high-mass compact star twins. While recently a wide range of radii, from 9 - 15 km, has been inferred for different neutron stars using different techniques, we perform our analysis under the supposition that the radii are towards the large end ($13-15$ km). We use this radius constraint together with the undebated statistically independent constraint for high masses ($\sim 2~M_\odot$) as priors in selecting the most probable hybrid equations of state from a family with two free parameters: the baryon excluded volume in the hadronic phase and the 8-quark vector channel interaction in the quark matter phase.

astro-ph.HE↗

Bayesian Analysis of Hybrid EoS based on Astrophysical Observational Data

We perform a Bayesian analysis of probability measures for compact star equations of state using new, disjunct constraints for mass and radius. The analysis uses a simple parametrization for hybrid equations of state to investigate the possibility of a first order deconfinement transition in compact stars. The latter question is relevant for the possible existence of a critical endpoint in the QCD phase diagram under scrutiny in heavy-ion collisions.

astro-ph.HE↗