6533b7defe1ef96bd1275b07
RESEARCH PRODUCT
N22e(α,n)M25g: The Key Neutron Source in Massive Stars
Karl KratzB. PfeifferG. StaudtR. KunzJ. W. HammerM. JaegerA. Mayersubject
Nuclear physicsPhysicsExcitation functionReaction rateStarsRange (particle radiation)General Physics and AstronomyNeutron sourceResonances-processOmegadescription
The excitation function of the reaction (22)Ne(alpha,n)(25)Mg, the key neutron source in the astrophysical s process in massive stars, has been determined from threshold at E(alpha) = 570 up to 1450 keV with an experimental sensitivity of 10(-11) b. For all resonances in this energy range new resonance parameters have been measured. For a possible resonance at about 635 keV a new upper limit omega gamma < 60 neV for the strength was obtained. Based on the new data, improved reaction rates were calculated as a function of temperature. The new uncertainty limits are considerably smaller than in previous determinations, ruling out the large enhancement factors, up to 500, assumed in some stellar model calculations.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2001-10-24 | Physical Review Letters |