Moxon-Rae setup for the measurement of stellar ({ital n},{gamma}) rates and the example of {sup 87}Rb

Journal Article · Wed May 01 04:00:00 EDT 1996 · Physical Review, C

DOI:https://doi.org/10.1103/PhysRevC.53.2474· OSTI ID:283983

Jaag, S; Kaeppeler, F ^[1]

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1. Forschungszentrum Karlsruhe, IK-III, Postfach 3640, D-76021 Karlsruhe (Federal Republic of Germany)

A setup with Moxon-Rae detectors was optimized for measurements of ({ital n},{gamma}) cross sections in the keV region. The experimental technique makes use of the quasi-Maxwellian spectrum that can be obtained via the {sup 7}Li({ital p},{ital n}){sup 7}Be reaction and is particularly suited for the determination of Maxwellian-averaged cross sections for nucleosynthesis studies related to {ital s}-process scenarios. It allows measurements at extremely short flight paths with the time-of-flight method as an option for background reduction. The experimental determination of the efficiency with calibrated {gamma} sources and with two-step cascades from selected resonances of the {sup 34}S({ital p},{gamma}) reaction revealed new properties of the response function. The reliability of the method was first demonstrated at the example of the well-known ratio of the ({ital n},{gamma}) cross sections of Ta and Au, and then used for a measurement of the stellar {sup 87}Rb cross section. With this new value {l_angle}{sigma}{ital v}{r_angle}/{ital v}{sub {ital T}}=15.5{plus_minus}1.5 mb, a discrepancy in the previously existing data could be resolved. {copyright} {ital 1996 The American Physical Society.}

• OSTI ID: 283983
• Journal Information: Physical Review, C, Journal Name: Physical Review, C Journal Issue: 5 Vol. 53; ISSN PRVCAN; ISSN 0556-2813
• Country of Publication: United States
• Language: English

Related Subjects

44 INSTRUMENTATION
INCLUDING NUCLEAR AND PARTICLE DETECTORS
66 PHYSICS
BERYLLIUM 7
CROSS SECTIONS
GOLD
KEV RANGE
LITHIUM 7 TARGET
NEUTRON REACTIONS
NEUTRONS
NUCLEOSYNTHESIS
PHOTODETECTORS
PHOTONS
PROTON REACTIONS
RESONANCE
RESPONSE FUNCTIONS
RUBIDIUM 87
RUBIDIUM 87 TARGET
SULFUR 34 TARGET
TANTALUM