Перегляд за автором "Wyatt, A.F.G."

Сортувати за: Порядок: Результатів:

  • Tanatarov, I.V.; Adamenko, I.N.; Nemchenko, K.E.; Wyatt, A.F.G. (Физика низких температур, 2010)
    We analyse the dispersion relation of ripplons, on the surface of superfluid helium, using the dispersive hydrodynamics approach and find a new ripplon branch. We obtain analytical equation for the dispersion relation and ...
  • Adamenko, I.N.; Nemchenko, K.E.; Slipko, V.A.; Wyatt, A.F.G. (Физика низких температур, 2008)
    Collective modes are studied in superfluid helium when the normal and superfluid components have a relative velocity w. In this paper the general dispersion relation for first and second sound modes is obtained for ...
  • Adamenko, I.N.; Kitsenko, Yu.A.; Nemchenko, K.E.; Slipko, V.A.; Wyatt, A.F.G. (Физика низких температур, 2007)
    The problem of the creation of high-energy phonons (h-phonons) by a pulse of low-energy phonons (l-phonons) moving from a heater to a detector in superfluid helium, is solved. The rate of h-phonon creation is obtained ...
  • Adamenko, I.N.; Nemchenko, K.E.; Slipko, V.A.; Wyatt, A.F.G. (Физика низких температур, 2004)
    The evolution of a pulse of noninteracting quasiparticles, caused by their different velocities and angular distribution of momenta, is studied theoretically. Equations are found that describe the shape of the pulse ...
  • Adamenko, I.N.; Kitsenko, Yu.A.; Nemchenko, K.E.; Wyatt, A.F.G. (Физика низких температур, 2009)
    We analyse the important role of four-phonon processes (4pp) in isotropic phonon systems of superfluid helium. The matrix elements and the rate of four-phonon processes are calculated. Special consideration is given to the ...
  • Tanatarov, I.V.; Adamenko, I.N.; Nemchenko, K.E.; Wyatt, A.F.G. (Вопросы атомной науки и техники, 2012)
    We use dispersive hydrodynamics to describe thermal excitations of superfluid helium 4. Dispersion relation of the bulk quasiparticles, phonons and rotons, acts as an input parameter of the theory. Wiener and Hopf method ...
  • Adamenko, I.N.; Kitsenko, Yu.A.; Nemchenko, K.E.; Slipko, V.A.; Wyatt, A.F.G. (Вопросы атомной науки и техники, 2007)
    The analytical relation for the rate of one phonon decay into three is obtained. Starting from the relation obtained, the rate of spontaneous decay in the first order of perturbation theory is found. It is shown, that ...
  • Adamenko, I.N.; Kitsenko, Y.A.; Nemchenko, K.E.; Wyatt, A.F.G. (Вопросы атомной науки и техники, 2001)
    We present a theoretical investigation of the kinetic properties of strongly anisotropic phonon systems. Such systems can be created in superfluid helium by heat pulses. The general expression for the rates of four-phonon ...
  • Adamenko, I.N.; Nemchenko, K.E.; Slipko, V.A.; Wyatt, A.F.G. (Физика низких температур, 2007)
    We discuss a number of unusual phenomena, which have been discovered recently in anisotropic quasiparticle systems in superfluid ⁴He. These include the creation of high-energy phonons by a pulse of low-energy phonons, ...
  • Adamenko, I.N.; Kitsenko, Yu.A.; Nemchenko, K.E.; Slipko, V.A.; Wyatt, A.F.G. (Физика низких температур, 2005)
    Starting from the kinetic equation for phonons in superfluid helium, expressions for the rates of three-phonon scattering in isotropic and anisotropic phonon systems were obtained for different pressures. These expressions ...
  • Tucker, M.A.H.; Wyatt, A.F.G.; Адаменко, И.Н.; Жуков, А.В.; Немченко, К.Э (Физика низких температур, 1999)
    Исходя из гидродинамического гамильтониана Ландау получено выражение для характерной частоты трехфононных процессов в сверхтекучем ⁴He, справедливое во всем диапазоне фононных энергий, при которых разрешены трехфононные ...