Speaker
Dr
Antonio Caciolli
(INFN Padova)
Description
Hydrogen burning of 17O sensitively influences nucleosynthesis in a number of stellar sites, including red giants, asymptotic giant branch (AGB) stars, massive stars, and classical novae. In particular, the ratio between reaction rates of 17O(p,alpha)14N (Q = 1.2 MeV) and 17O(p,g)18F (Q = 5.6 MeV) channels on 17O is one of the most important parameters for the galactic synthesis of 17O, the stellar production of radioactive 18F, and for predicted O isotopic ratios in premolar grains.
Now the LUNA collaboration operating inside the underground laboratories of LNGS is preparing a new effort to study the (p,alpha) channel on 17O at astrophysical energies. To reach this goal a new chamber has been constructed which allows to place 8 silicons detectors covering almost half of the total solid angle in backward directions. The setup improves the efficiency which is a crucial parameter in measuring nuclear reaction at such low energies. Aluminum foils are placed on the silicon in order to stop the elastic backscattered protons which otherwise produce non negligible background on the silicons. The target chamber is made by two semispherical structures: one holds the silicon and the other one made in copper is connected to the beam line cold trap in order to avoid contaminants on the target surface and to keep cold the silicons reducing the noise also in the low energy region where we expect the alpha particles signal.
for the collaboration
LUNA
Primary authors
Dr
Antonio Caciolli
(INFN Padova)
Mr
David Scott
(SUPA, School of Physics and Astronomy, University of Edinburgh, Edinburgh, UK)
