Measuring excitation functions needed to interpret cosmogenic nuclide production in lunar rocks
- Harvard Cyclotron Laboratory, Harvard University, Cambridge, Massachusetts 02138 (United States)
- Department of Chemistry, San Jose State University, San Jose, California 92192 (United States)
- Institute of Geophysics and Planetary Physics, Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)
- TRIUMF, University of British Columbia, Vancouver, British Columbia, V6T2A3 (Canada)
- Crocker Nuclear Laboratory, University of California, Davis, California 95616 (United States)
- Los Alamos National Laboratory, Group NIS-2, Los Alamos, New Mexico 87545 (United States)
Radionuclides produced in lunar rocks by cosmic ray interactions are measured using Accelerator Mass Spectrometry or gamma-ray spectroscopy. From these measurements, estimates of the solar proton flux over time periods characterized by the half-life of the isotope under study can be made, if all the cross sections for all the reactions of all cosmic ray particles with all elements found in lunar rocks are known. Proton production cross sections are very important because {approximately}98{percent} of solar cosmic rays and {approximately}87{percent} of galactic cosmic rays are protons in the lunar environment. Many of the needed cross sections have never been measured. Targets of C, Al, Si, SiO{sub 2}, Mg, K, Ca, Fe and Ni have been irradiated using three accelerators to cover a proton energy range of 25{endash}500 MeV. Excitation functions for {sup 7}Be, {sup 10}Be, {sup 22}Na, and {sup 26}Al production from Mg and Al will be reported, and the consequences of using these new cross section values to estimate solar proton fluxes discussed. {copyright} {ital 1997 American Institute of Physics.}
- Research Organization:
- Lawrence Livermore National Laboratory
- Sponsoring Organization:
- USDOE
- DOE Contract Number:
- W-7405-ENG-48
- OSTI ID:
- 580001
- Report Number(s):
- CONF-961110--
- Journal Information:
- AIP Conference Proceedings, Journal Name: AIP Conference Proceedings Journal Issue: 1 Vol. 392; ISSN APCPCS; ISSN 0094-243X
- Country of Publication:
- United States
- Language:
- English
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