We report on measurements of resonance strengths and energies for the Ep = 151 and 193 keV resonances in the 18O(p,gamma)15N and 17O(p,gamma)14N reactions, respectively, obtained during commissioning of a new setup for alpha-particle detection studies at the LUNA underground laboratory. Our values, omegagamma(151) = 164.2 ± 0.9 stat+12.1−11.7 syst meV and omegagamma(193) = 1.68 ± 0.03 stat ± 0.12 syst meV, are in excellent agreement with those reported in the literature. New values of resonance energies are Ep = 151.2±0.3keV and Ep = 194.8 ± 0.3 keV, respectively, this latter with the highest precision to date. Comparative background measurements in silicon detectors overground and underground were also carried out, yielding up to a factor of 15 in background suppression at LUNA at energies around 200 keV. This clearly demonstrates the usefulness of underground measurements in charged-particles experiments, especially at low detection energies.
Resonance strengths in the 17,18O(p,gamma)14,15N reactions and background suppression underground
F. CAVANNA;P. CORVISIERO;P. PRATI;
2015-01-01
Abstract
We report on measurements of resonance strengths and energies for the Ep = 151 and 193 keV resonances in the 18O(p,gamma)15N and 17O(p,gamma)14N reactions, respectively, obtained during commissioning of a new setup for alpha-particle detection studies at the LUNA underground laboratory. Our values, omegagamma(151) = 164.2 ± 0.9 stat+12.1−11.7 syst meV and omegagamma(193) = 1.68 ± 0.03 stat ± 0.12 syst meV, are in excellent agreement with those reported in the literature. New values of resonance energies are Ep = 151.2±0.3keV and Ep = 194.8 ± 0.3 keV, respectively, this latter with the highest precision to date. Comparative background measurements in silicon detectors overground and underground were also carried out, yielding up to a factor of 15 in background suppression at LUNA at energies around 200 keV. This clearly demonstrates the usefulness of underground measurements in charged-particles experiments, especially at low detection energies.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.