Resonance strengths in the 14N(p,gamma)15O astrophysical key reaction measured with activation

Abstract

The 14N(p,gamma)15O reaction plays a vital role in various astrophysical scenarios. Its reaction rate must be accurately known in the present era of high precision astrophysics. The cross section of the reaction is often measured relative to a low energy resonance, the strength of which must therefore be determined precisely. The activation method, based on the measurement of 15O decay, has not been used in modern measurements of the 14N(p,gamma)15O reaction. The aim of the present work is to provide strength data for two resonances in the 14N(p,gamma)15O reaction using the activation method. The obtained values are largely independent from previous data measured by in-beam gamma-spectroscopy and are free from some of their systematic uncertainties. Solid state TiN targets were irradiated with a proton beam provided by the Tandetron accelerator of Atomki using a cyclic activation. The decay of the produced 15O isotopes was measured by detecting the 511 keV positron annihilation gamma-rays. The strength of the Ep = 278 keV resonance was measured to be 13.4 +- 0.8 meV while for the Ep = 1058 keV resonance the strength is 442 +- 27 meV. The obtained Ep = 278 keV resonance strength is in fair agreement with the values recommended by two recent works. On the other hand, the Ep = 1058 keV resonance strength is about 20% higher than the previous value. The discrepancy may be caused in part by a previously neglected finite target thickness correction. As only the low energy resonance is used as a normalization point for cross section measurements, the calculated astrophysical reaction rate of the 14N(p,gamma)15O reaction and therefore the astrophysical consequences are not changed by the present results.

arXiv commentAccepted for publication in Phys. Rev. C

References in corpus (10)

• Solar fusion cross sections II: the pp chain and CNO cycles
• S-factor of 14N(p,gamma)15O at astrophysical energies
• CN-Cycle Solar Neutrinos and Sun's Primordial Core Metalicity
• Direct measurement of the 14N(p,g)15O S-factor
• The activation method for cross section measurements in nuclear astrophysics
• The Impact of Nuclear Reaction Rate Uncertainties On The Evolution of Core-Collapse Supernova Progenitors
• Resonance strengths in the 14N(p, γ)15O and 15N(p, αγ)12C reactions
• The ${}^{14}N(p,\gamma {)}^{15}O$ reaction, solar neutrinos and the age of the globular clusters
• Astrophysical S-factor of the ${}^{14}\text{N(p,}\gamma {\text{)}}^{15}\text{O}$ reaction at 0.4 -- 1.3\,MeV
• Cross section measurement of the astrophysically important 17O(p,gamma)18F reaction in a wide energy range

Cited by in corpus (9)

• Setup commissioning for an improved measurement of the D(p,gamma)3He cross section at Big Bang Nucleosynthesis energies
• Advances in Radiative Capture Studies at LUNA with a Segmented BGO Detector
• Exploring Stars in Underground Laboratories: Challenges and Solutions
• Solar fusion III: New data and theory for hydrogen-burning stars
• Cross section measurement of the 12C(p,gamma)13N reaction with activation in a wide energy range
• Activation cross section measurement of the 14N(p,gamma)15O astrophysical key reaction
• Stable beam experiments in wide energy ranges serving low energy nuclear astrophysics
• The challenging first direct measurement of the 65 keV resonance strength in the ${}^{17}$O(p,$\gamma$)${}^{18}$F reaction at LUNA
• Green's Function Formalism for Impurity-Induced Resonances in Sub-barrier Proton-Nucleus Scattering