Creation of high-energy phonons by four-phonon processes in anisotropic phonon systems of He II
Vernadsky National Library of Ukraine
Переглянути архів Інформація| Поле | Співвідношення | |
| Title |
Creation of high-energy phonons by four-phonon processes in anisotropic phonon systems of He II
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| Creator |
Adamenko, I.N.
Kitsenko, Yu.A. Nemchenko, K.E. Slipko, V.A. Wyatt, A.F.G. |
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| Subject |
Квантовые жидкости и квантовые кpисталлы
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| Description |
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 and it is shown that created h-phonons occupy a much smaller solid angle in momentum space, than the l-phonons. An analytical expression for the creation rate of h-phonon, along the symmetry axis of a pulse, are derived. It allows us to get useful approximate analytical expressions for the creation rate of h-phonons. The time dependences of the parameters which describe the l-phonon pulse are obtained. This shows that half of the initial energy of l-phonon pulse can be transferred into h-phonons. The results of the calculations are compared with experimental data and we show that this theory explains a number of experimental results. The value of the momentum, which separates the l- and h-phonon subsystems, is found. |
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| Date |
2017-12-28T12:54:17Z
2017-12-28T12:54:17Z 2007 |
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| Type |
Article
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| Identifier |
Creation of high-energy phonons by four-phonon processes in anisotropic phonon systems of He II / I.N. Adamenko, Yu.A. Kitsenko, K.E. Nemchenko, V.A. Slipko, A.F.G. Wyatt // Физика низких температур. — 2007. — Т. 33, № 5. — С. 523-537. — Бібліогр.: 22 назв. — англ.
0132-6414 PACS: 67.70.+n, 68.08.–p, 62.60.+v http://dspace.nbuv.gov.ua/handle/123456789/127809 |
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| Language |
en
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| Relation |
Физика низких температур
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| Publisher |
Фізико-технічний інститут низьких температур ім. Б.І. Вєркіна НАН України
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