Mirage-effect measurement of thermal diffusivity. Part I: experiment

Kuo, P. K.; Lin, M. J.; Reyes, C. B.; Favro, L. D.; Thomas, R. L.; Kim, D. S.; Zhang, Shuyi; Inglehart, L. J.; Fournier, Danièle; Boccara, Albert‐Claude; Yacoubi, N.

doi:10.1139/p86-202

Cited by 100 publications

(22 citation statements)

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“…It has been shown theoretically [4,5] that the ratios of the slopes of such plots correspond, in the low frequency limit, to the ratios of the actual diffusivities of the solid. The numerical constant which relates the thermal diffusivity to the slope depends on the value of h. The previous measurements [1][2][3] of a, carried out using the "skimming" optical probe beam technique (see Fig. 1), were found to be in reasonable agreement with nominal values calculated from handbook data, provided that the slopes of the plots were set equal (llPuristically) to (1.0 1Ta )1/2.…”

Section: Introductionsupporting

confidence: 54%

“…[1][2][3] This is carried out by scanning the probe beam relative to the heating beam with a constant height, h. The separation, x o ' of the two points on either side of the center of such a scan where the phase of the transverse deflection signal reaches ninety degrees effectively measures the thermal wavelength, A = 2(1Ta / f) 1/2 in the solid. The determination of the thermal diffusivity, a , is accomplished by plotting this separat ion versus the inverse square root of the frequency.…”

Section: Introductionmentioning

confidence: 99%

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Reflection-Mirage Measurements of Thermal Diffusivity

Reyes

Jaarinen

Favro

et al. 1987

Review of Progress in Quantitative Nondestructive Evaluation

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Section: Introductionsupporting

confidence: 54%

Section: Introductionmentioning

confidence: 99%

Reflection-Mirage Measurements of Thermal Diffusivity

Reyes

Jaarinen

Favro

et al. 1987

Review of Progress in Quantitative Nondestructive Evaluation

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“…This photothermal deflection (PD) technique has proved to be very useful in characterizing various physical and chemical properties (absorption spectra, thermal diffusivity, etc.) of solid, liquid and gaseous materials [1,2,[4][5][6][7]. Here, for the first time, this new photothermal method has been applied to the in vivo measurement of thermal deactivation of excited pigments in intact plant leaves.…”

Section: Introductionmentioning

confidence: 99%

In vivo measurement of spectroscopic and photochemical properties of intact leaves using the ‘mirage effect’

1989

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This paper describes a new, highly sensitive, method for in vivo studies of photosynthesis based on the 'mirage effect' in which thermal energy dissipation from intact leaves, illuminated with intensity-modulated light, is sensed through the periodic deflection of a laser beam propagating along the leaf surface. The photothermal deflection technique allows one to rapidly estimate the gross efficiency of photochemical energy storage by comparing the heat emission signal with and without an additional strong, photosynthetically saturating, non-modulated light. In pea leaves, the maximal storage efficiency at low light intensities was shown to approach 55%. The general utility of this simple photothermal method is illustrated by examining the variation of the deflection signal under different conditions. The spectral resolution of this new method is shown to be much higher than that of the photoacoustic method.

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“…Again, a number of techniques have been developed to measure the thermal diffusivity of bulk samples [5,6]. Of late photothermal techniques employing the photoacoustic [7,8], photothermal deflection [9,10], or photopyroelectric [11,12] effects have become very popular for the measurement of the thermal diffusivity of bulk samples. However, these techniques are limited to bulk samples with minimum thickness of about 1 mm or so.…”

Section: Introductionmentioning

confidence: 99%

Thermal diffusion in thin plates and coatings: influence of thickness and substrate material

Soumya¹,

Philip²

2016

Turk J Phys

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Abstract:The dependence of thermal diffusivity/conductivity on thickness for a variety of coatings and free-standing thin metallic plates was measured using a traveling photothermal technique. The selected materials have large differences in terms of their thermal conductivity. Measurements were carried out on coatings prepared on substrates with two widely different values for thermal conductivity to bring out the influence of substrate thermal conductivity on the thermal diffusivity/conductivity of the coating. Thermal diffusivity/conductivity increases exponentially with coating thickness with the value saturating at a definite thickness. The variation follows an empirical relation, which can predict thermal diffusivity of a coating at any thickness in the low thickness regime. In the region where thermal diffusivity increases exponentially with thickness, thermal diffusivity of the coating is lower when the substrate is a better thermal conductor, implying that thermal waves diffuse into substrate causing an overall reduction in thermal diffusivity. However, beyond the saturation thickness the thermal diffusivity is independent of substrate material. Thermal conductivity of coatings as well as thin metallic plates follows analogous variations with thickness and substrate material. The results will help in providing a better theoretical description of heat transport in low dimensional structures.

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Mirage-effect measurement of thermal diffusivity. Part I: experiment

Abstract: A mirage-effect thermal-wave method for the measurement of thermal diffusivities of solids is described. Data from two different laboratories are provided for various pure elements and compound semiconductor materials. In most cases the agreement with literature values is good.

Cited by 100 publications

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Reflection-Mirage Measurements of Thermal Diffusivity

Reflection-Mirage Measurements of Thermal Diffusivity

In vivo measurement of spectroscopic and photochemical properties of intact leaves using the ‘mirage effect’

Thermal diffusion in thin plates and coatings: influence of thickness and substrate material

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