Neutron capture and total cross sections for /sup 48/Ca: astrophysical implications

Conference · Sun Jan 01 04:00:00 EST 1984

OSTI ID:6395745

Carlton, R F; Harvey, J A; Hill, N W; Macklin, R L

Attempts to understand abundance anomalies of the Ca isotopes in the Allende meteorite via the n..beta..-process require 30-keV Maxwellian averaged capture cross sections. Experimental data on /sup 48/Ca in this energy region of astrophysical significance is important since a single resonance in this vicinity could dominate the capture cross section. Neutron capture and total cross section measurements have been performed at ORELA on a 9.97-g sample of CaCO/sub 3/, enriched to 96% /sup 48/Ca, over the energy ranges 10 eV to 500 keV (sigma/sub ..gamma../) and 10 keV to 4MeV (sigma/sub T/). Only two small resonances were found for /sup 48/ Ca in the 30-keV energy region (at 19.3 and 106.9 keV) and those only in capture. Their contribution to the 30-keV-averaged cross section is only 50 ..mu..b compared to 1.0 mb calculated from direct capture. The p-wave strength and large d/sub 5/2/ strength observed above 150 keV do not contribute significantly to the 30 keV capture.

• Research Organization: Middle Tennessee State Univ., Murfreesboro (USA); Oak Ridge National Lab., TN (USA)
• DOE Contract Number: AC05-84OR21400; AS05-80ER10710
• OSTI ID: 6395745
• Report Number(s): CONF-840906-2; ON: DE85001759
• Country of Publication: United States
• Language: English

Related Subjects

651525* -- Nuclear Properties & Reactions
A=39-58
Experimental-- Nuclear Reactions & Scattering-- (-1987)
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
ALKALINE EARTH METALS
BARYON REACTIONS
CALCIUM
CALCIUM 48 TARGET
CAPTURE
CHEMICAL COMPOSITION
CROSS SECTIONS
DATA
ELEMENTS
ENERGY RANGE
EV RANGE
EXPERIMENTAL DATA
HADRON REACTIONS
INFORMATION
ISOTOPE RATIO
KEV RANGE
METALS
METEORITES
MEV RANGE
MEV RANGE 01-10
NEUTRON REACTIONS
NUCLEAR REACTIONS
NUCLEON REACTIONS
NUMERICAL DATA
RESONANCE
TARGETS
TOTAL CROSS SECTIONS