Cryogenic apparatus for study of near-field heat transfer

0368238 - ÚPT 2012 RIV US eng J - Journal Article
Králík, Tomáš - Hanzelka, Pavel - Musilová, Věra - Srnka, Aleš - Zobač, Martin
Cryogenic apparatus for study of near-field heat transfer.
Review of Scientific Instruments. Roč. 82, č. 5 (2011), 055106:1-5. ISSN 0034-6748. E-ISSN 1089-7623
R&D Projects: GA AV ČR IAA100650804
Institutional research plan: CEZ:AV0Z20650511
Keywords : cryogenics * heat measurement * heat radiation * micrometry * radiative transfer * thermistors
Subject RIV: BJ - Thermodynamics
Impact factor: 1.367, year: 2011

For bodies spaced in vacuum at distances shorter than the wavelength of the thermal radiation, radiative heat transfer substantially increases due to the contribution of evanescent electromagnetic waves. Experimental data on heat transfer in near-field regime are scarce. We have designed a cryogenic apparatus for the study of heat transfer over microscopic distances between metallic and non-metallic surfaces. Using a mechanical positioning system, a planeparallel gap between the samples, concentric disks, each 35 mm in diameter, is set and varied from 10(0) to 10(3) mu m. The heat transferred from the hot (10 - 100 K) to the cold sample (similar to 5 K) sinks into a liquid helium bath through a thermal resistor, serving as a heat flux meter. Transferred heat power within similar to 2 nW/cm(2) and similar to 30 mu W/cm(2) is derived from the temperature drop along the thermal resistor.
Permanent Link: http://hdl.handle.net/11104/0202636