J. Phys. IV France
Volume 109, June 2003
Page(s) 49 - 57

J. Phys. IV France
109 (2003) 49
DOI: 10.1051/jp4:20030651

R-hyperbolic functions - A new tool for description of thermalwaves

M. Malinski

Faculty of Electronics, Technical University of Koszalin, 17 Partyzantow St., 75-411 Koszalin,Poland

A general new method of description of thermal waves for the case of samples placed on a different backing material is presented and discussed. New functions of the R-hyperbolic type useful for the proper description of the periodical temperature fields and periodical photoacoustic and piezoelectric signais are proposed and described. They were applied for a description of several cases most frequently met in photoacoustic and photothermal methods. The paper comprises among others general equations for the ratio of the magnitudes and the phase-lag between the front and rear photoacoustic signals, instantaneous temperature spatial distributions in a sample and the equations describing the piezoelectric signal. All these formula are expressed in a domain of R-hyperbolic functions. This paper presents in general a strong influence of the backing material on photothermal characteristics.

© EDP Sciences 2003