12,000

We have over 12,000 students, from over 100 countries, within one of the safest campuses in the UK

93%

93% of Lancaster students go into work or further study within six months of graduating

Home > Research > Publications & Outputs > New approach to enhanced heat exchange efficien...
View graph of relations

« Back

New approach to enhanced heat exchange efficiencies at ultralow temperatures

Research output: Contribution to journalComment/debate

Published

Journal publication date1/06/1986
JournalPhysical Review B
Journal number11
Volume33
Number of pages3
Pages7803-7805
Original languageEnglish

Abstract

We examine the heat transfer between a sintered metallic powder and liquid 3He at ultralow temperatures. With the combination of a renormalization-group approach with the Lanczos method, a microscopic model is analyzed to yield the low-frequency density of states ρ(ω) of the sinter. In the weak-coupling limit ρ(ω) possesses a pronounced low-frequency peak leading to an enhanced heat transfer coefficient at low temperatures. This enhancement is shown to occur when the ratio of the long-wavelength velocity of sound Cs in the sinter to its velocity Cb in the bulk metal is small and can be optimized by minimizing this ratio.