Autor: Masarik, J.; Nishiizumi, K.; Reedy, R. C.
Názov: Production rates of cosmogenic helium-3, neon-21, and neon-22 in ordinary chondrites and the lunar surface
Typ: publication
Dátum: 2001
Jazyk: en
Poznámka:
Abstrakt:
The production of ³He, ²¹Ne, and ²²Ne in meteoroids of various sizes and in the lunar
surface was investigated. The LAHET code system, a purely physical model for calculating cosmic-
ray particle fluxes, was used to simulate cosmic-ray particle interactions with extraterrestrial matter.
We discuss the depth and size dependence of the shielding parameter ²²Ne/²¹Ne, which is used for
reconstruction of pre-atmospheric sizes, depth, and exposure histories. The ²²Ne/²¹Ne ratio decreases
with increasing depth or pre-atmospheric size but then increases with depth in very large objects.
This increase with depth in the ²²Ne/²¹Ne ratio means that this ratio is a poor indicator of shielding in
some large objects. The dependence of ³He/²¹Ne Ne as function of ²²Ne/²¹Ne was also calculated, and
differences between the calculations and the Bern line are discussed.
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