High-performance thermal emitters based on laser-engineered metal surfaces

Abstract

Effective thermal management is of paramount importance for all high-temperature systems operating under vacuum. Cooling of such systems relies mainly on radiative heat transfer requiring high spectral emissivity of surfaces, which is strongly affected by the surface condition. Pulsed laser structuring of stainless steel in air resulted in the spectral hemispherical emissivity values exceeding 0.95 in the 2.5–15 µm spectral region. The effects of surface oxidation and topography on spectral emissivity as well as high temperature stability of the surface structures were examined. High performance stability of the laser textured surfaces was confirmed after thermal aging studies at 320°C for 96 hours.

Efficient Combination of Surface Texturing and Functional Coating for Very Low Secondary Electron Yield Surfaces and Rough Nonevaporable Getter Films

“…Furthermore the surfaces of the redeposited nanoparticles might not reach the same temperature for the given heating power due to lower thermal conductivity through the nanoparticles and a higher emissivity of the rough surface. [ 75 ] However, annealing at 250 °C leads to a consistent degree of surface activation. This result is interesting since the higher effective surface area of rough films potentially allows a higher pumping speed and adsorption capacity as getter material if properly activated.…”

Thermal modelling, conception and design of a cooling system for the LHC injection Kicker Magnets towards High Luminosity LHC operation

“…The best performing samples had an emissivity exceeding 0.95 in the spectral region between 2.5µm and 15µm. Furthermore, high performance stability of the LESS surface was confirmed after thermal aging studies at 320•C for 96 hours [85].…”