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The Solar System Boron Abundance: a Measurement of Boron Concentration in Carbonaceous Chondritic Meteorites


Weller, Martha Carroll Riherd (1979) The Solar System Boron Abundance: a Measurement of Boron Concentration in Carbonaceous Chondritic Meteorites. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/qr8h-9k53.


Boron concentrations were determined for six carbonaceous chondritic meteorites using the reaction 11B(d,p)12B. The results imply a solar system B/H ratio of (2 ± 1) x 10-9. Although this ratio is much lower than that determined from previous meteoritic measurements, it remains significantly higher than the B/H ratios determined from the solar photosphere and other astrophysical environments.

Light element abundance ratios obtained from both meteoritic and photospheric data are compared with calculated values. It is concluded that two contributions are probably necessary to account for the observed ratios. Lithium, beryllium and boron nuclei produced according to the standard galactic cosmic ray model are expected to contribute significantly to the observed abundances. However, a component arising from low-energy spallation of CNO nuclei also appears necessary. Several possibilities are considered for the origin of these low-energy particles. However, the data and calculations are too uncertain to permit any firm conclusions.

Item Type:Thesis (Dissertation (Ph.D.))
Subject Keywords:Physics
Degree Grantor:California Institute of Technology
Division:Physics, Mathematics and Astronomy
Major Option:Physics
Thesis Availability:Public (worldwide access)
Research Advisor(s):
  • Tombrello, Thomas A.
Thesis Committee:
  • Tombrello, Thomas A.
Defense Date:30 November 1978
Funding AgencyGrant Number
Record Number:CaltechTHESIS:09242018-101823585
Persistent URL:
Default Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:11195
Deposited On:30 Nov 2018 20:12
Last Modified:16 Apr 2021 23:32

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