{sup 134,136}Ba(n,{gamma}) cross sections for s-process studies

Journal Article · Sun Oct 01 04:00:00 EDT 1995 · Bulletin of the American Physical Society

OSTI ID:255573

Spencer, R R; Guber, K H; Koehler, P E ^[1]

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1. Oak Ridge National Laboratory, TN (United States); and others

The isotopes of barium play a vital role in s-process nucleosynthesis; hence an accurate determination of their (n,{gamma}) cross sections is very important for a better understanding of the s-process. A recent measurements of {sup 134,136}Ba(n,{gamma}) cross sections yielded an astrophysical reaction rate significantly different from the previously accepted value. Furthermore, substantial uncertainties remain in the reaction rate at the low temperatures (kT{approx}12 keV) favored by recent stellar models, because neither of the previous measurements extended to sufficiently low neutron energies. We have recently completed measurements of the {sup 134,136}Ba(n,{gamma}) cross sections from approximately 20 eV to 100 keV. These data, together with our concurrent measurements of the total cross sections for these nuclei, should result in a much more accurate determination of the astrophysical reaction rates near kT=12 keV. The measurements were performed at the Oak Ridge Electron Linear Accelerator (ORELA) using our recently improved C{sub 6}D{sub 6} detector apparatus. We will describe the experiment and report on the results and their impact on s-process nucleosynthesis models.

• DOE Contract Number: AC05-84OR21400
• OSTI ID: 255573
• Report Number(s): CONF-9510116--
• Journal Information: Bulletin of the American Physical Society, Journal Name: Bulletin of the American Physical Society Journal Issue: 10 Vol. 40; ISSN BAPSA6; ISSN 0003-0503
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
BARIUM 134
BARIUM 136
NEUTRON DETECTORS
NEUTRON REACTIONS
S PROCESS
TOTAL CROSS SECTIONS