Cross sections for production of the 15. 10-MeV and other astrophysically significant gamma-ray lines through excitation and spallation of /sup 12/C and /sup 16/O with protons

Journal Article · Wed Apr 01 00:00:00 EST 1987 · Phys. Rev. C; (United States)

DOI:https://doi.org/10.1103/PhysRevC.35.1214· OSTI ID:5977948

Lang, F L; Werntz, C W; Crannell, C J; Trombka, J I; Chang, C C

The ratio of the flux of 15.10-MeV gamma rays to the flux of 4.438-MeV gamma rays resulting from excitation of the corresponding states in /sup 12/C is a sensitive measure of the spectrum of the exciting particles produced in solar flares and other cosmic sources. These gamma rays are produced predominantly by interactions with /sup 12/C and /sup 16/O, both of which are relatively abundant in the solar photosphere. Gamma-ray production cross sections for proton interactions have been reported previously for all important channels except for the production of 15.10-MeV gamma rays from /sup 16/O. The first reported measurement of the 15.10-MeV gamma-ray production cross section from p+ /sup 16/O is presented here. A cyclotron was employed to produce 40-, 65-, and 85-MeV protons which interacted with CH/sub 2/ and BeO targets. The resultant gamma-ray spectra were measured with a high-purity germanium semiconductor detector at 70, 90, 110, 125, and 140 deg relative to the direction of the incident beam for each proton energy. Other gamma-ray lines resulting from direct excitation and spallation reactions with /sup 12/C and /sup 16/O were observed as well, and their gamma-ray production cross sections, several of which have not been reported previously, are presented. The results are compared with previously reported measurements, as available.

• Research Organization: Code 682, Solar Physics Branch, Laboratory for Astronomy and Solar Physics, NASA/Goddard Space Flight Center, Greenbelt, Maryland 20771 and Department of Physics, The Catholic University of America, Washington, D.C. 20064
• OSTI ID: 5977948
• Journal Information: Phys. Rev. C; (United States), Vol. 35:4
• Country of Publication: United States
• Language: English

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73 NUCLEAR PHYSICS AND RADIATION PHYSICS
CARBON 12 TARGET
PROTON REACTIONS
OXYGEN 16 TARGET
SPALLATION
ANGULAR DISTRIBUTION
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BORON 10
BORON 11
CARBON 11
CROSS SECTIONS
CYCLOTRONS
GAMMA SPECTRA
MEV RANGE 10-100
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NITROGEN 15
OXYGEN 15
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BARYON REACTIONS
BETA DECAY RADIOISOTOPES
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BORON ISOTOPES
CARBON ISOTOPES
CHARGED-PARTICLE REACTIONS
CYCLIC ACCELERATORS
DISTRIBUTION
ENERGY RANGE
EVEN-ODD NUCLEI
HADRON REACTIONS
ISOTOPES
LIGHT NUCLEI
MEV RANGE
MINUTES LIVING RADIOISOTOPES
NITROGEN ISOTOPES
NUCLEAR REACTIONS
NUCLEI
NUCLEON REACTIONS
ODD-EVEN NUCLEI
ODD-ODD NUCLEI
OXYGEN ISOTOPES
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651320* - Nuclear Properties & Reactions
A=6-19
Experimental