Thermal radiative properties of some cryogenic materials

Tsujimoto, Soichiro; Kanda, Masutaro; Kunitomo, Takeshi

doi:10.1016/0011-2275(82)90007-8

Cited by 16 publications

(12 citation statements)

References 13 publications

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“…The Al samples compared in figure 5 were provided with different surface treatments such as chemical polishing (our measurement), electro-polishing [10], fine mechanical polishing followed by annealing [7] or evaporated Al layers [17,25,26]. Despite different approaches to emissivity measurement, there is generally a good match among presented experimental methods.…”

Section: Example Of Measurement and Results Verificationmentioning

confidence: 99%

“…Figure 5 also includes two values of the total hemispherical emissivity at 300 K calculated from formerly published optical constants of aluminium [25,26]. Tsujimoto et al [7] gained their results from spectral measurements of bulk Al. They used Al and Au standards for measurement of infrared spectra (wavelengths 1-20 μm) of normal reflectivity at temperatures between 16 and 306 K and calculated total hemispherical absorptivity and emissivity from a proposed model.…”

Section: Example Of Measurement and Results Verificationmentioning

confidence: 99%

“…limits of the reflectivity method used in [7] for measurement of absorptivity of nearly 100% reflecting samples.…”

Section: Example Of Measurement and Results Verificationmentioning

confidence: 99%

“…Metals show weak wavelength dependence of spectral emissivity, ε(T, λ) ~ 1/λ n with n ≈ 0 -2/3, in far infrared. For example absorptivity of gold, aluminium and copper weakly depends on wavelengths relevant to the maximum of emissive power of black-body at a temperature of about 300 K [7,24]. On the other hand at cryogenic temperatures of radiation, with wavelengths in far infrared, a stronger dependence of up to n ≈ 2/3 is expected, namely for metals proving anomalous skin effect [24].…”

Section: Correction For Non-gray Surface Of the Measured Samplementioning

confidence: 99%

“…At cryogenic temperatures measurement of total hemispherical emissivity of metallic samples [1], of directional total emissivity of 'black' paints [6] or spectral measurement of normal absorptivity of metallic samples [7] can serve as an example. Recently, a measuring technique of total emissivity with improved background subtraction Metrologia Method for measurement of emissivity and absorptivity of highly reflective surfaces from 20 K to room temperatures Tomáš Králík, Věra Musilová, Pavel Hanzelka and Jiří Frolec for investigation of highly reflective samples at temperatures higher than 80 K has been introduced [8] and applied for measuring stainless steel plates and the effect of silver coating [9].…”

Section: Introductionmentioning

confidence: 99%

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Method for measurement of emissivity and absorptivity of highly reflective surfaces from 20 K to room temperatures

et al. 2016

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We present a cryogenic method for the measurement of total hemispherical emissivity and absorptivity of various materials at temperatures from 320 K down to ≈20 K. In absorptivity measurement the temperature of the examined sample is kept at ≈5 K–35 K. Radiative heat flow between two plane parallel surfaces of 40 mm in diameter disk samples placed in a vacuum, a sample and a disk with reference surface, is absorbed by a colder sample and sinks into an LHe bath via a thermal resistor (heat flow meter). Heat flow is measured by substitution method, using thermal output of an electrical heater for heat flow meter calibration. A great deal of attention is paid to the estimation of uncertainties associated with this method. Capabilities of the instrument are demonstrated by the absorptivity and emissivity measurement of the pure aluminium sample. The expanded fractional uncertainty (k = 2) in emissivity ε = 0.0041 measured at ≈30 K for pure aluminium is less than 11% and for values of emissivity ε > 0.0053 measured above 60 K the uncertainties are below 7%. The method was designed primarily for the measurement of highly reflective materials like pure metals, nevertheless high emissivity of the reference sample also enables the measurement of non-metallic materials with reasonable accuracy.

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