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

Abstract

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.

Authors:
; ; ; ;  [1];  [2]; ; ; ;  [3]; ;  [4];  [2]; ;  [5]; ; ;  [6]; ; more »;  [7];  [8];  [9] « less
  1. Universita degli Studi Genova, Via dodecaneso 33, 16146 Genova (Italy)
  2. (Italy)
  3. INFN Sezione di Padova, Padova (Italy)
  4. Istituto di Fisica Generale Applicata, Universita di Milano (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)
Publication Date:
OSTI Identifier:
20798567
Resource Type:
Journal Article
Resource Relation:
Journal Name: AIP Conference Proceedings; Journal Volume: 831; Journal Issue: 1; Conference: International conference on frontiers in nuclear structure, astrophysics, and reactions - FINUSTAR, Isle of Kos (Greece), 12-17 Sep 2005; Other Information: DOI: 10.1063/1.2200958; (c) 2006 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
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

Citation Formats

Lemut, A., Confortola, F., Corvisiero, P., Costantini, H., Prati, P., INFN Geneva, Via dodecaneso 33, 16146 Genova, Bemmerer, D., Broggini, C., Menegazzo, R., Rossi Alvarez, C., Bonetti, R., Guglielmetti, A., INFN Milan, Cruz, J., Jesus, A. P., Formicola, A., Gustavino, C., Junker, M., Fueloep, Zs., Gyuerky, G., Somorjai, E., Gervino, G., and INFN Torino, Turin. Low energy underground study of 14N(p,{gamma})15O cross section. United States: N. p., 2006. Web. doi:10.1063/1.2200958.
Lemut, A., Confortola, F., Corvisiero, P., Costantini, H., Prati, P., INFN Geneva, Via dodecaneso 33, 16146 Genova, Bemmerer, D., Broggini, C., Menegazzo, R., Rossi Alvarez, C., Bonetti, R., Guglielmetti, A., INFN Milan, Cruz, J., Jesus, A. P., Formicola, A., Gustavino, C., Junker, M., Fueloep, Zs., Gyuerky, G., Somorjai, E., Gervino, G., & INFN Torino, Turin. Low energy underground study of 14N(p,{gamma})15O cross section. United States. doi:10.1063/1.2200958.
Lemut, A., Confortola, F., Corvisiero, P., Costantini, H., Prati, P., INFN Geneva, Via dodecaneso 33, 16146 Genova, Bemmerer, D., Broggini, C., Menegazzo, R., Rossi Alvarez, C., Bonetti, R., Guglielmetti, A., INFN Milan, Cruz, J., Jesus, A. P., Formicola, A., Gustavino, C., Junker, M., Fueloep, Zs., Gyuerky, G., Somorjai, E., Gervino, G., and INFN Torino, Turin. Wed . "Low energy underground study of 14N(p,{gamma})15O cross section". United States. doi:10.1063/1.2200958.
@article{osti_20798567,
title = {Low energy underground study of 14N(p,{gamma})15O cross section},
author = {Lemut, A. and Confortola, F. and Corvisiero, P. and Costantini, H. and Prati, P. and INFN Geneva, Via dodecaneso 33, 16146 Genova and Bemmerer, D. and Broggini, C. and Menegazzo, R. and Rossi Alvarez, C. and Bonetti, R. and Guglielmetti, A. and INFN Milan and Cruz, J. and Jesus, A. P. and Formicola, A. and Gustavino, C. and Junker, M. and Fueloep, Zs. and Gyuerky, G. and Somorjai, E. and Gervino, G. and INFN Torino, Turin},
abstractNote = {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.},
doi = {10.1063/1.2200958},
journal = {AIP Conference Proceedings},
number = 1,
volume = 831,
place = {United States},
year = {Wed Apr 26 00:00:00 EDT 2006},
month = {Wed Apr 26 00:00:00 EDT 2006}
}