Ci. Um et al., THERMAL-CONDUCTIVITY AND VISCOSITY IN DILUTE HE-3-HE-4 MIXTURES BELOW0.6 K, Journal of low temperature physics, 109(3-4), 1997, pp. 495-510
The effects of three-phonon processes on the phonon thermal conductivi
ty and phonon viscosity in dilute He-3-He-4 mixtures below 0.6 K are i
nvestigated The characteristic scattering times for phonon-phonon inte
raction-limited thermal conductivity and viscosity are calculated from
a collision matrix which contains information on the three-phonon pro
cesses. We find that die to phonon-He-3 interactions the phonon moment
um range in which three-phonon processes occur is reduced in compariso
n with that of the pure He-4 case. Results for thermal conductivity an
d viscosity show good agreement with experimental data without having
to adjust the rates of phonon absorption by He-3 and the tares of elas
tic scattering of phonons with He-3.