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Method for the analysis of thermal-pulse data

: Bauer, S.


Physical Review. B 47 (1993), Nr.17, S.11049-11055
ISSN: 0163-1829
ISSN: 1098-0121
ISSN: 0556-2805
Fraunhofer HHI ()
data analysis; electrets; polymers; thermal conductivity of solids; thermal diffusivity; thermal pulse data analysis; thermal-pulse experiments; approximation; electric-field distribution; differential operators; thermal-pulse- response equation; space charges; dipoles; negatively corona-charged teflon polyfluoroethylene propylene sample; electron-beam-charged teflon sample; electret film

A method for the analysis of thermal-pulse experiments is developed. An approximation for the electric-field distribution is calculated from the thermal-pulse data in a simple way, avoiding mathematical instabilities. The heart of the method is a set of appropriately constructed differential operators. It is shown that the thermal-pulse-response equation is exactly solved by the application of these differential operators. The application of the first-order differential operator suffices to reconstruct to a very good approximation the field distributions within electrets containing space charges or dipoles. The method of analysis is especially suitable for the probing of electric-field distributions near the sample surface. Furthermore, the technique allows an on-line analysis of thermal-pulse data. The merit of the method is demonstrated with measured thermal-pulse data obtained with a negatively corona-charged Teflon polyfluoroethylene propylene sample and with an electron-beam-charged Teflon sample. Additionally, the thermal diffusivity of the electret film is measurable with the thermal-pulse technique if the field distribution within the sample is known.