Abstract
The creation and decay rates of high-energy phonons ($h$-phonons) in anisotropic systems of low-energy phonons ($l$-phonons), are calculated using the exact distribution function for anisotropic phonon systems in superfluid helium. The angular distribution of created $h$-phonons is then found, and it is shown that the solid angle occupied by created $h$-phonons is always less than the solid angle occupied by $l$-phonons, as is found experimentally. The evolution of the $l$-phonon pulse, due to $h$-phonon creation, is analyzed. This leads to an explanation of the measured dependence of the $l$-phonon signal on heater power.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.