Accession Number:

AD0408445

Title:

PULSE PROPAGATION INTO WATER

Descriptive Note:

Corporate Author:

HARVARD UNIV CAMBRIDGE MA CRUFT LAB

Personal Author(s):

Report Date:

1963-03-18

Pagination or Media Count:

34.0

Abstract:

The transmission of short unidirectional plane wave pulses into water and solutions of sodium chloride has been investigated experimentally. The time sequence of the transient response for incident pulses with a duration of several nano seconds is observed at various depths in the electrolyte. The dispersion of the pulse is mainly due to the ionic conductance of the solution. For very rapid polarizing forces the relaxation associated with the hindered rotation of the water molecules also contributes to the dispersion. Unlike the exponential attenuation of sinu soidal signals in conducting media, for short pulses the maximum response ultimately follows an inverse cube law with increasing depth. The experimental results are compared to the calculated transient response obtained from an approximate theory. The agreement is excellent.

Subject Categories:

  • Radiofrequency Wave Propagation

Distribution Statement:

APPROVED FOR PUBLIC RELEASE