geometric attenuation

geometric attenuation

[‚jē·ə¦me·trik ə‚ten·yə′wā·shən]
(nucleonics)
That part of the reduction in the intensity of ionizing radiation with distance from a source which is associated with spreading out of the radiation and is independent of the interaction of the radiation with matter.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
References in periodicals archive ?
In this figure, the attenuation of the [A.sub.0] mode at 66 kHz for a near top source and the [S.sub.0] mode at 539 kHz for a mid-plane source are compared to the amplitude-based geometric attenuation of a wave spreading in-plane.
It is interesting to note that the added attenuation relative to geometric attenuation for these mode/frequency combinations is about 12 to 15 dB for these two cases.
For the axially symmetric model, it is often sufficient to consider merely so-called geometric attenuation following from the radial spread of waves through the environment, and material attenuation may be omitted in this case (Rayleigh attenuation coefficients are null).