Analytical calculation of the transient temperature of a sample in a Xenon flash test, based on the measured radiation intensity of the Xenon gas discharge tube
When thermal diffusivity is determined experimentally by the xenon flash method, measuring accuracy with thin samples or materials with high thermal diffusivity depends chiefly on the variation of the radiation intensity of the xenon source. There has not so far been any satisfactory approximation function for the time response of xenon flash lamps. This work provides an analytical solution to the one-dimensional thermal conduction equation, where the relative radiation intensity of any xenon gas discharge tube measured can be obtained by approximating the marginal flow condition piece by piece with exponential functions. In an example the relative radiation intensity of a 1 000 Ws xenon gas discharge tube is measured and approximated step-wise by 3 exponential functions. In the case of the initial or marginal conditions assumed here, the transient sample temperature can be given as a convolution integral. It can be integrated very simply by selecting exponential functions as approximation functions for the relative radiation intensity of the source. There is also a discussion of the transient processes which take place during a flash test and of the transient temperature of very thin samples.
Bibliographic Reference: Report: Jül-Spez-504 DE (89) 33 pp.
Availability: Available from Zentralbibliothek der Kernforschungsanlage Jülich GmbH, Postfach 1913, 5170 Jülich (DE)
Record Number: 199010402 / Last updated on: 1994-12-01
Original language: de
Available languages: de