Speaker
Rosanna Depalo
(INFN LNL)
Description
The results from the lifetime measurement of the first 3/2+ state in 15O are
discussed. This state corresponds to a sub-threshold resonance in the 14N(p,γ)15O
reaction, the slowest one of the CNO cycle. The accurate determination of the
width of this resonance is of paramount importance in the evaluation of the
astrophysical factor and the derived cross section [1]. For this purpose, an
experiment was performed to measure the lifetime of the first 3/2+ state in 15O,
decaying by a 6.792 MeV E1 transition to the ground state, by means of the
Doppler Shift Attenuation method. Gamma rays were detected by the AGATA
Demonstrator, placed close to the beam line, providing a continuous angular
distribution of the emitted gamma rays.
The first excited states in 15O (and 15N) were populated via nucleon transfer and
fusion-evaporation reactions of 14N on 2H (implanted at the surface of a ~4
mg/cm2 Au layer) at 32 MeV beam energy, provided by the XTU Tandem at LNL.
The procedure and steps followed in the data analysis are described together with
some results of the high-energy gammas calibration. Spectra of several high-
energy gamma rays de-exciting 1-10 fs lifetime levels in the populated nuclei will
be shown and compared with the result of detailed simulations.
[1] C. Peña-Garay and A. M. Sereneli, in preparation (2008) and arXiv: 0811.2424v1 [astro-ph]
Primary author
Caterina Michelagnoli
(INFN and University of Padova)
Co-authors
Andrea Gottardo
(INFN LNL)
Antonio Caciolli
(INFN Padova)
Calin Ur
(INFN Padova)
Carlo Broggini
(INFN Padova)
Carlos Rossi Alvarez
(INFN Padova)
Daniel Bemmerer
(elmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany)
Daniele Mengoni
(INFN Padova)
Dino Bazzacco
(INFN Padova)
Eda Sahin
(INFN LNL)
Enrico Farnea
(INFN Padova)
Fay Filmer
(University of Liverpool, Liverpool, UK)
Francesco Recchia
(INFN Padova)
Giovanni Pollarolo
(INFN and Università di Torino, Torino, Italy)
Jose Javier Valiente-Dobon
(INFN LNL)
Martin Erhard
(INFN Padova)
Michele Marta
(Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany)
Dr
Roberto Menegazzo
(INFN Padova)
Rosanna Depalo
(INFN LNL)
Ryan Kempley
(Department of Physics of the University of Surrey, Guildford, UK)
Ryan McAdoo
(INFN LNL)
Prof.
Santo Lunardi
(INFN and University of Padova)
T. Szuecs
(ATOMKI, Debrecen, Hungary)
Tea Mijatovic
(Ruder Boșkoviċ Institute, Zagreb, Croatia)
Zsolt Fueloep
(ATOMKI, Debrecen, Hungary)
