Search academic texts

Information × Registration Number 0218U007225, 0118U003870 , R & D reports Title Kinetic properties of nanostructured and mesoscopic quantum systems formed by condensed phases of helium. popup.stage_title Head Birchenko Oleksandr Petrovich, Registration Date 02-01-2019 Organization B.Verkin Institute for Low Temperature Physics and Engineering NAS of Ukraine popup.description2 Experimental studies of the quasiluminar flow in superluminal helium with excitatory oscillations of a quartz tuning fork, immersed in a liquid, have been carried out. Nonlinear oscillations that arise when increasing the excitatory force and are manifested by the distortion of the shape of the resonant amplitude-frequency characteristic in comparison with the Lorentz curves typical for extremely small forces are investigated. Also received nonlinear resonance curves described using the Duffing equation, and the coefficient of nonlinearity of the tuning fork is determined. The processes of structural relaxation in non-equilibrium helium crystals, which were obtained by crystallization of the liquid under rapid cooling, were studied by precision barometric method. In the course of the experiment, the values of the pressure at the ends of the cylindrical measuring cell with solid helium and their change over time with stepwise heating of the sample were measured. The analysis of experimental results on relaxation kinetics is carried out. The obtained results are interpreted in the framework of a monovacuum model of the diffusion mechanism of structural relaxation. Product Description popup.authors Бірченко Олександр Петрович Михайленко Христина Олексіївна Фисун Яна Юріївна Шарапова Ірина Володимирівна popup.nrat_date 2020-04-02 Close