Berlin 2005 – wissenschaftliches Programm

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HK: Physik der Hadronen und Kerne

HK 22: Postersitzung

HK 22.95: Poster

Montag, 7. März 2005, 16:30–18:00, TU MA141

The ¹⁴N(p,γ)¹⁵O reaction at energies of astrophysical interest — •Daniel Bemmerer — Istituto Nazionale di Fisica Nucleare, Sezione di Padova, Italy, and Institut für Atomare Physik und Fachdidaktik, Technische Universität Berlin, Germany

The ¹⁴N(p,γ)¹⁵O reaction is the bottleneck of the hydrogen-burning CNO cycle. At the LUNA 400 kV accelerator deep underground in the Gran Sasso laboratory, its cross section has been measured in the E_CM = 130 – 370 keV energy range using a TiN solid target and germanium detectors [1]. The resulting astrophysical S-factor extrapolated to zero energy is only half the previously accepted value, with interesting consequences for the age determination of globular clusters [2].

The present talk reports on the subsequent measurement [3] of the total cross section of this reaction in the E_CM = 70 – 230 keV energy range using a windowless gas target and a 4π BGO detector at the LUNA accelerator. The results are consistent with [1] and extend the data to energies that lie within the Gamow peak for some stars.

[1] A. Formicola et al., Phys. Lett. B 591 (2004), 61 - 68.

[2] G. Imbriani et al., Astronomy & Astrophysics 420 (2004), 625 - 629.

[3] http://edocs.tu-berlin.de/diss/2004/bemmerer_daniel.htm