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Ultra sound absorption measurements in rock samples at low temperaturesA new technique, comparable with the reverberation method in room acoustics, is described. It allows Q-measurements at rock samples of arbitrary shape in the frequency range of 50 to 600 kHz in vacuum (.1 mtorr) and at low temperatures (+20 to -180 C). The method was developed in particular to investigate rock samples under lunar conditions. Ultrasound absorption has been measured at volcanics, breccia, gabbros, feldspar and quartz of different grain size and texture yielding the following results: evacuation raises Q mainly through lowering the humidity in the rock. In a dry compact rock, the effect of evacuation is small. With decreasing temperature, Q generally increases. Between +20 and -30 C, Q does not change much. With further decrease of temperature in many cases distinct anomalies appear, where Q becomes frequency dependent.
Document ID
19740052807
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
Authors
Herminghaus, C.
Berckhemer, H.
(Frankfurt, Universitaet Framkfurt am Main, Germany)
Date Acquired
August 7, 2013
Publication Date
January 1, 1974
Publication Information
Publication: Zeitschrift fuer Geophysik
Volume: 40
Issue: 3, 19
Subject Category
Geophysics
Accession Number
74A35557
Funding Number(s)
CONTRACT_GRANT: DFG-BE-299/36
CONTRACT_GRANT: BMBW-WRK-246
Distribution Limits
Public
Copyright
Other

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