Premium
Cosmic‐ray tracks and cobalt‐60 in near‐surface samples of the Jilin chondrite
Author(s) -
PERRON C.,
BOUROTDENISE M.,
PELLAS P.,
HEUSSER G.,
OUYANG Z.
Publication year - 1996
Publication title -
meteoritics and planetary science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.09
H-Index - 100
eISSN - 1945-5100
pISSN - 1086-9379
DOI - 10.1111/j.1945-5100.1996.tb02041.x
Subject(s) - radius , ordinary chondrite , meteoroid , analytical chemistry (journal) , cobalt , chondrite , geology , materials science , mineralogy , astrophysics , physics , chemistry , meteorite , metallurgy , astronomy , computer security , chromatography , computer science
— Cosmic‐ray track densities (CRTDs) have been measured on several spot samples from two Jilin specimens from the strewn field (VI‐21‐057 and VI‐42‐04), along with 60 Co activity in three and four sections, respectively, of the same specimens. The observed CRTD gradient agrees remarkably well with that predicted by Bhattacharya et al .'s calculations (1973) of CRTD variation as a function of shielding depth, which indicates a negligible contribution from the first 2π‐irradiation stage. The shortest distance of each specimen to the preatmospheric surface is 3.6 cm and 6.8 cm, respectively. The distance scale deduced from these measurements allows the determination of the variation of 60 Co activity with shielding depth, at low depth values, which is found to be much less steep than model predictions. Two slightly different 60 Co profiles are proposed that correspond to the two specimens studied. The mean preatmospheric radius of the Jilin chondrite is 85 ± 8 cm, the uncertainty reflecting in part the meteoroid surface roughness.