Nuclear Structure of<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msup><mml:mrow><mml:mi mathvariant="normal">F</mml:mi></mml:mrow><mml:mrow><mml:mn>18</mml:mn></mml:mrow></mml:msup></mml:mrow></mml:math>

Polsky, L.; Holbrow, Charles H.; Middleton, R.

doi:10.1103/physrev.186.966

Cited by 39 publications

(37 citation statements)

References 23 publications

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“…Different than resonance parameters these parameters are only restricted by the respective cross sections. Because ANC values are only poorly restricted from the present data set, literature values derived from transfer reactions [29,30] were taken where appropriate.…”

Section: R-matrix Analysis and Discussionmentioning

confidence: 99%

“…The spectroscopic factors C 2 S were then compared to literature spectroscopic factors from transfer reactions [29,30] 2 to determine their validity (Table III). If a fitted ANC of a given transition corresponds to a spectroscopic factor that is much larger than the one found in literature, that indicates that the transition cannot be fully described by the external capture component of the R-matrix theory, and a background pole is required.…”

Section: R-matrix Analysis and Discussionmentioning

confidence: 99%

“…As there are no available proton scattering data or other appropriate experimental data to constrain the proton partial widths of the poles, they were fixed at Γ p = 6 MeV, chosen close to the Wigner limit given by the formula Γ W = 2P l (E r )γ W , where P l (E r ) is the penetrability factor for a given partial wave at the resonance energy and γ W = (3/2)h 2 /(µr Table III. In bold font are the ANCs that were fixed according to literature spectroscopic factors from [29]. The latter values were preferred over those from [30] since the nuclear potential used in that work was identical to the one used in this work for the conversion of the ANCs to spectroscopic factors.…”

Section: R-matrix Analysis and Discussionmentioning

confidence: 99%

“…Note that a 23% variation of the ANC corresponds to a 50% variation in the respective spectroscopic factor. The reported uncertainties of the spectroscopic factors in [29] are 25%, but given the uncertainties involved in converting spectroscopic factors from transfer reactions to ANCs, a conservative 50% uncertainty was adopted. All the tests mentioned allow for a reasonable upper limit estimation of the uncertainty attributed solely to the R-matrix extrapolation, by adding the variations in quadrature.…”

Section: R-matrix Analysis and Discussionmentioning

confidence: 99%

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Proton capture on17O and its astrophysical implications

et al. 2012

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Background: The reaction17 O(p, γ) 18 F influences hydrogen-burning nucleosynthesis in several stellar sites, such as red giants, asymptotic giant branch (AGB) stars, massive stars and classical novae. In the relevant temperature range for these environments (T9 = 0.01-0.4), the main contributions to the rate of this reaction are the direct capture process, two low lying narrow resonances (Er = 65.1 and 183 keV) and the low-energy tails of two broad resonances (Er = 557 and 677 keV).Purpose: Previous measurements and calculations give contradictory results for the direct capture contribution which in turn increases the uncertainty of the reaction rate. In addition, very few published cross section data exist for the high energy region that might affect the interpretation of the direct capture and the contributions of the broad resonances in the lower energy range. This work aims to address these issues.Method: The reaction cross section was measured in a wide proton energy range (Ec.m. = 345 -1700 keV) and at several angles (θ lab = 0• , 45The observed primary γ-transitions were used as input in an R-matrix code in order to obtain the contribution of the direct capture and the two broad resonances to the low-energy region.Results: The extrapolated S-factor from the present data is in good agreement with the existing literature data in the low-energy region. A new reaction rate was calculated from the combined results of this work and literature S-factor determinations. Resonance strengths and branchings are reported for several 18 F states. Conclusions:We were able to extrapolate the astrophysical S-factor of the reaction 17 O(p, γ) 18 F at low energies from cross section data taken at higher energies. No significant changes in the nucleosynthesis are expected from the newly calculated reaction rate.

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Section: R-matrix Analysis and Discussionmentioning

confidence: 99%

Section: R-matrix Analysis and Discussionmentioning

confidence: 99%

Section: R-matrix Analysis and Discussionmentioning

confidence: 99%

Section: R-matrix Analysis and Discussionmentioning

confidence: 99%

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Proton capture on17O and its astrophysical implications

et al. 2012

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“…Replacing the three renormalized values in the set of ACLM produces no significant change 6 except for the appearance of a second 3 + state in F 18 at about 4 MeV where an excellent experimental candidate is seen. 7 For J= 2, T = 0 there is only one matrix element in the space, and the disagreement is only ficticious since ACLM included in their search the 2 + state at 2.52 MeV in F 18 which was later shown 8 to be 4p-2h (four-particle, two-hole) and, therefore, out of the model space. In the case of J= 1, T = 0 the discrepancy is more real.…”

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confidence: 99%