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Westphal, W. B.

Publications and source records attributed to Westphal, W. B..

Dielectric spectra of Apollo 15 and 16 lunar solid samples

Description of the dielectric constants, losses, and ac-conductivities of lunar samples 15065,27, 15459,62, 15555,88, 15415,57, 60015,29, 60315,34, 61016,34, and 62235,17 as measured over a range of frequencies from 100 Hz to 10 MHz and temperatures from 77 to 473 K by two-terminal capacitance substitution methods. The dielectric spectra of lunar gabbroic basalts are typified by the dielectric behavior of samples 15065 and 15555, showing complex relaxation processes which are both frequency- and temperature-dependent. Such feldspar-rich crystalline lunar basalts like samples 15459, 62235, and 60015 showed essentially the same dielectric relaxation mechanisms which are also a function of both frequency and temperature with a very broad relaxation frequency distribution. Highly-brecciated lunar sample, 60315, exhibits rather an unusual dielectric behavior which is dependent upon on field-strength.

Chung, D. H.↗

Dielectric properties of Apollo 14 lunar samples.

Laboratory characterization of dielectric properties of lunar samples 14301,41, 14310,75, 14318,30 and 14321,163 is made. Our measurements of dielectric constants and losses were made over a range of frequency from 100 Hz to 10 MHz and temperature from 77 to 473 K by two-terminal capacitance substitution methods. The dielectric behavior of these samples is generally similar to other lunar samples from Apollo 11 and Apollo 12 sites when these samples are free from absorbed moisture. As did sample 12002,58, sample 14310,75 showed a distinctive dispersion that may be associated with the presence of water, and different values of the activation energy for conduction as the temperature was varied. The activation energies range from about 0.03 to 0.5 eV.

Chung, D. H.↗