skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: The {sup 139}La(n,{gamma}) cross section: Key for the onset of the s-process

Abstract

The nuclear resonance parameters and the capture cross section of the neutron magic isotope {sup 139}La have been measured relative to {sup 197}Au in the energy range of 0.6 eV to 9 keV at the neutron time-of-flight (n{sub T}OF) facility at CERN. We describe the experimental apparatus and the data analysis procedures, which concerned mainly the efficiency correction by means of the pulse height weighting function technique and the determination of different background components. We extracted the resonance parameters and the main nuclear quantities such as the resonance integral RI=10.8{+-}1.0b, the average {gamma} widths for s and p waves <{gamma}{sub {gamma}}>{sub l=0}=50.7{+-}5.4 meV and <{gamma}{sub {gamma}}>{sub l=1}=33.6{+-}6.9 meV, the nuclear level densities <D>{sub l=0}=252{+-}22 eV and <D>{sub l=1}<250 eV, and the neutron strength functions S{sub 0}=(0.82{+-}0.05)x10{sup -4} and S{sub 1}=(0.55{+-}0.04)x10{sup -4}. These results represent a significant improvement over previous data. The deduced Maxwellian-averaged capture cross sections are important for the interpretation of the most recent spectroscopic observations in low-metallicity stars.

Authors:
; ; ;  [1]; ; ; ;  [2]; ; ; ; ; ; ; ;  [3]; ; ;  [4];  [5]
  1. Dipartimento di Fisica and Istituto Nazionale di Fisica Nucleare, Bari (Italy)
  2. Istituto Nazionale di Fisica Nucleare, Trieste (Italy)
  3. CEA/Saclay-DSM, Gif-sur-Yvette (France)
  4. Universidade de Santiago de Compostela (Spain)
  5. Centro de Investigaciones Energeticas Medioambientales y Technologicas, Madrid (Spain) (and others)
Publication Date:
OSTI Identifier:
20995174
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physical Review. C, Nuclear Physics; Journal Volume: 75; Journal Issue: 3; Other Information: DOI: 10.1103/PhysRevC.75.035807; (c) 2007 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
73 NUCLEAR PHYSICS AND RADIATION PHYSICS; CAPTURE; CERN; CROSS SECTIONS; EV RANGE 01-10; GOLD 197; KEV RANGE 01-10; LANTHANUM 139; MEV RANGE; NEUTRONS; P WAVES; RESONANCE INTEGRALS; S PROCESS; STRENGTH FUNCTIONS; WEIGHTING FUNCTIONS

Citation Formats

Terlizzi, R., Colonna, N., Marrone, S., Tagliente, G., Abbondanno, U., Fujii, K., Milazzo, P. M., Moreau, C., Aerts, G., Andriamonje, S., Berthoumieux, E., Dridi, W., Gunsing, F., Pancin, J., Perrot, L., Plukis, A., Alvarez, H., Duran, I., Paradela, C., and Alvarez-Velarde, F. The {sup 139}La(n,{gamma}) cross section: Key for the onset of the s-process. United States: N. p., 2007. Web. doi:10.1103/PHYSREVC.75.035807.
Terlizzi, R., Colonna, N., Marrone, S., Tagliente, G., Abbondanno, U., Fujii, K., Milazzo, P. M., Moreau, C., Aerts, G., Andriamonje, S., Berthoumieux, E., Dridi, W., Gunsing, F., Pancin, J., Perrot, L., Plukis, A., Alvarez, H., Duran, I., Paradela, C., & Alvarez-Velarde, F. The {sup 139}La(n,{gamma}) cross section: Key for the onset of the s-process. United States. doi:10.1103/PHYSREVC.75.035807.
Terlizzi, R., Colonna, N., Marrone, S., Tagliente, G., Abbondanno, U., Fujii, K., Milazzo, P. M., Moreau, C., Aerts, G., Andriamonje, S., Berthoumieux, E., Dridi, W., Gunsing, F., Pancin, J., Perrot, L., Plukis, A., Alvarez, H., Duran, I., Paradela, C., and Alvarez-Velarde, F. Thu . "The {sup 139}La(n,{gamma}) cross section: Key for the onset of the s-process". United States. doi:10.1103/PHYSREVC.75.035807.
@article{osti_20995174,
title = {The {sup 139}La(n,{gamma}) cross section: Key for the onset of the s-process},
author = {Terlizzi, R. and Colonna, N. and Marrone, S. and Tagliente, G. and Abbondanno, U. and Fujii, K. and Milazzo, P. M. and Moreau, C. and Aerts, G. and Andriamonje, S. and Berthoumieux, E. and Dridi, W. and Gunsing, F. and Pancin, J. and Perrot, L. and Plukis, A. and Alvarez, H. and Duran, I. and Paradela, C. and Alvarez-Velarde, F.},
abstractNote = {The nuclear resonance parameters and the capture cross section of the neutron magic isotope {sup 139}La have been measured relative to {sup 197}Au in the energy range of 0.6 eV to 9 keV at the neutron time-of-flight (n{sub T}OF) facility at CERN. We describe the experimental apparatus and the data analysis procedures, which concerned mainly the efficiency correction by means of the pulse height weighting function technique and the determination of different background components. We extracted the resonance parameters and the main nuclear quantities such as the resonance integral RI=10.8{+-}1.0b, the average {gamma} widths for s and p waves <{gamma}{sub {gamma}}>{sub l=0}=50.7{+-}5.4 meV and <{gamma}{sub {gamma}}>{sub l=1}=33.6{+-}6.9 meV, the nuclear level densities <D>{sub l=0}=252{+-}22 eV and <D>{sub l=1}<250 eV, and the neutron strength functions S{sub 0}=(0.82{+-}0.05)x10{sup -4} and S{sub 1}=(0.55{+-}0.04)x10{sup -4}. These results represent a significant improvement over previous data. The deduced Maxwellian-averaged capture cross sections are important for the interpretation of the most recent spectroscopic observations in low-metallicity stars.},
doi = {10.1103/PHYSREVC.75.035807},
journal = {Physical Review. C, Nuclear Physics},
number = 3,
volume = 75,
place = {United States},
year = {Thu Mar 15 00:00:00 EDT 2007},
month = {Thu Mar 15 00:00:00 EDT 2007}
}