Near field radiative heat transfer between macro-scale metallic surfaces at cryogenic temperatures

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F68081731%3A_____%2F21%3A00549394" target="_blank" >RIV/68081731:_____/21:00549394 - isvavai.cz</a>

Výsledek na webu

<a href="https://www.sciencedirect.com/science/article/pii/S0011227520301582" target="_blank" >https://www.sciencedirect.com/science/article/pii/S0011227520301582</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.cryogenics.2020.103156" target="_blank" >10.1016/j.cryogenics.2020.103156</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Near field radiative heat transfer between macro-scale metallic surfaces at cryogenic temperatures

Popis výsledku v původním jazyce

Knowledge of radiative heat transfer between bodies at various temperatures is essential for efficient design of cryogenic devices. Radiative far-field heat transfer is commonly taken into account. Nevertheless, when the distance d between components of a device becomes small, smaller than the characteristic wavelength of Planck's far field thermal radiation, an additional heat transfer caused by thermal electromagnetic near-field starts to play a role. At cryogenic temperatures and micrometric distances, this near field heat transfer can exceed the far-field one by orders of magnitude. We report experimental results on near-field and far-field heat fluxes q transferred across a plane parallel vacuum gap d between pair of identical copper (RRR = 10) and tungsten (RRR = 1.5) samples. The heat flux q was measured over the distances d = 1–100 μm and for various temperatures T2 = 15–80 K of the hot sample and the temperature T1 down to 5 K of the cold one. We compare the copper and tungsten data with previously published results for normal metals Nb and NbN. For each pair of identical samples, the measured values of near-field thermal conductance of vacuum gap, KT = q/(T2 − T1), collapse into nearly a single dependence on the gap size d. Thus for specific metallic surfaces, this relation enables estimate the near field heat flux at cryogenic temperatures over micrometric distances.

Název v anglickém jazyce

Near field radiative heat transfer between macro-scale metallic surfaces at cryogenic temperatures

Popis výsledku anglicky

Knowledge of radiative heat transfer between bodies at various temperatures is essential for efficient design of cryogenic devices. Radiative far-field heat transfer is commonly taken into account. Nevertheless, when the distance d between components of a device becomes small, smaller than the characteristic wavelength of Planck's far field thermal radiation, an additional heat transfer caused by thermal electromagnetic near-field starts to play a role. At cryogenic temperatures and micrometric distances, this near field heat transfer can exceed the far-field one by orders of magnitude. We report experimental results on near-field and far-field heat fluxes q transferred across a plane parallel vacuum gap d between pair of identical copper (RRR = 10) and tungsten (RRR = 1.5) samples. The heat flux q was measured over the distances d = 1–100 μm and for various temperatures T2 = 15–80 K of the hot sample and the temperature T1 down to 5 K of the cold one. We compare the copper and tungsten data with previously published results for normal metals Nb and NbN. For each pair of identical samples, the measured values of near-field thermal conductance of vacuum gap, KT = q/(T2 − T1), collapse into nearly a single dependence on the gap size d. Thus for specific metallic surfaces, this relation enables estimate the near field heat flux at cryogenic temperatures over micrometric distances.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10306 - Optics (including laser optics and quantum optics)

Projekt

<a href="/cs/project/GA20-00918S" target="_blank" >GA20-00918S: Souhra konvektivního přenosu tepla a turbulentních proudění s rotací v klasických a kvantových fázích kryogenního helia</a><br>

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2021

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Cryogenics

ISSN

0011-2275

e-ISSN

1879-2235

Svazek periodika

113

Číslo periodika v rámci svazku

January

Stát vydavatele periodika

GB - Spojené království Velké Británie a Severního Irska

Počet stran výsledku

6

Strana od-do

103156

Kód UT WoS článku

000618659400003

EID výsledku v databázi Scopus

2-s2.0-85099146919