Low energy underground study of 14N(p,{gamma})15O cross section

Journal Article · Wed Apr 26 00:00:00 EDT 2006 · AIP Conference Proceedings

DOI:https://doi.org/10.1063/1.2200958· OSTI ID:20798567

Lemut, A; Confortola, F; Corvisiero, P; Costantini, H; Prati, P ^[1]; Bemmerer, D; Broggini, C; Menegazzo, R; Rossi Alvarez, C ^[2]; Bonetti, R; Guglielmetti, A ^[3]; Milan, INFN ^[4]; Cruz, J; Jesus, A P ^[5]; Formicola, A; Gustavino, C; Junker, M ^[6]; Fueloep, Zs; Gyuerky, G; Somorjai, E ^[7] ; Gervino, G ^[8]; INFN Torino, Turin ^[9]

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1. Universita degli Studi Genova, Via dodecaneso 33, 16146 Genova (Italy)
2. INFN Sezione di Padova, Padova (Italy)
3. Istituto di Fisica Generale Applicata, Universita di Milano (Italy)
4. Italy
5. Centro de Fisica Nuclear da Universidade de Lisboa, Lisbon (Portugal)
6. INFN, Laboratori Nazionali del Gran Sasso, Assergi, L'Aquila (Italy)
7. ATOMKI, Debrecen (Hungary)
8. Dipartimento di Fisica Sperimentale, Universita di Torino, Torino (Italy)
9. Italy; and others

In stars, four hydrogen nuclei are converted into a helium nucleus by two competing nuclear fusion processes: the proton - proton chain (p-p) and the carbon - nitrogen - oxygen (CNO) cycle. At temperatures higher than 2x107 K, the CNO cycle dominates the energy production. In particular, its rate is determined by the slowest reaction: 14N(p,{gamma})15O. Direct measurement in a laboratory at the surface of the Earth is hampered by the background due to the cosmic rays. Here we report on an experiment performed with the LUNA (Laboratory for Underground Nuclear Astrophysics) accelerator placed deep underground in the INFN Gran Sasso laboratory (Italy). Thanks to the cosmic ray suppression provided by the mountain shield, we could measure the 14N(p,{gamma})15O cross section for the first time directly at energies corresponding to stellar temperatures and with unpreceedent accuracy. In particular we used a large solid angle BGO detector with a differentially pumped windowless gas target. The lowest measured energy is 70.1 keV. Our results have important consequences for the formation of carbon stars, for an independent lower limit on the age of the universe, and for solar neutrino flux.

• OSTI ID: 20798567
• Journal Information: AIP Conference Proceedings, Journal Name: AIP Conference Proceedings Journal Issue: 1 Vol. 831; ISSN APCPCS; ISSN 0094-243X
• Country of Publication: United States
• Language: English

Related Subjects

73 NUCLEAR PHYSICS AND RADIATION PHYSICS
ASTROPHYSICS
BGO DETECTORS
CAPTURE
CARBON STARS
CNO CYCLE
COSMIC NEUTRINOS
CROSS SECTIONS
HYDROGEN
KEV RANGE
NITROGEN 14
NITROGEN 14 TARGET
NUCLEOSYNTHESIS
OXYGEN 15
PROTON REACTIONS
PROTONS
SOLAR NEUTRINOS
UNDERGROUND