New neutron capture and transmission measurements for {sup 134,136}Ba at ORELA and their impact on s-process nucleosynthesis calculations

Conference · Tue Oct 01 04:00:00 EDT 1996

OSTI ID:392734

Koehler, P E; Spencer, R R ^[1]; Winters, R R ^[2]; Guber, K H; Harvey, J A; Hill, N W; Smith, M S ^[1]

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1. Oak Ridge National Lab., TN (United States)
2. Denison Univ., Granville, OH (United States). Dept. of Physics and Astronomy

We have made high-resolution neutron capture and transmission measurements on isotopically enriched samples of {sup 134}Ba and {sup 136}Ba at the Oak Ridge Electron Linear Accelerator (ORELA) in the energy range from 20 eV to 500 keV. Previous measurements had a lower energy limit of 3 - 5 keV, which is too high to determine accurately the Maxwellian-averaged capture cross section at the low temperatures (kT {approx} 6 - 12 keV) favored by the most recent stellar models of the {ital s}-process. Our results for the astrophysical reaction rates are in good agreement with the most recent previous measurement at the classical {ital s}-process temperature, kT = 30 keV, but show significant differences at lower 40 temperatures. We discuss the astrophysical implications of these differences.

• Research Organization: Oak Ridge National Lab., TN (United States)
• Sponsoring Organization: USDOE, Washington, DC (United States)
• DOE Contract Number: AC05-96OR22464
• OSTI ID: 392734
• Report Number(s): CONF-9606248--5; ON: DE96015223
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
ASTROPHYSICS
BARIUM 134
BARIUM 136
CAPTURE
EV RANGE 10-100
EV RANGE 100-1000
KEV RANGE 01-10
KEV RANGE 10-100
KEV RANGE 100-1000
NEUTRON REACTIONS
NUCLEOSYNTHESIS
S PROCESS