Study of proton resonances in 18Ne via resonant elastic scattering of 17F + p and its astrophysical implication in the stellar reaction of 14O(α, p)17F

J. J. He; J. Hu; S. W. Xu; Z. Q. Chen; X. Y. Zhang; J. S. Wang; H. W. Wang; W. D. Tian; X. Q. Yu; L. Y. Zhang; L. Li; Y. Y. Yang; P. Ma; X. H. Zhang; J. Su; E. T. Li; Z. G. Hu; Z. Y. Guo; X. Xu; X. H. Yuan; W. Lu; Y. H. Yu; Y. D. Zang; S. W. Ye; R. P. Ye; J. D. Chen; S. L. Jin; C. M. Du; S. T. Wang; J. B. Ma; L. X. Liu; Z. Bai; X. Q. Li; X. G. Lei; Z. Y. Sun; Y. H. Zhang; X. H. Zhou; H. S. Xu

doi:10.1140/epja/i2011-11067-6

2022 Impact factor 2.7

Hadrons and Nuclei

Eur. Phys. J. A (2011) 47: 67
https://doi.org/10.1140/epja/i2011-11067-6

Regular Article - Experimental Physics

Study of proton resonances in ¹⁸Ne via resonant elastic scattering of ¹⁷F + p and its astrophysical implication in the stellar reaction of ¹⁴O(α, p)¹⁷F

J. J. He¹^*, J. Hu¹^,2, S. W. Xu¹, Z. Q. Chen¹, X. Y. Zhang¹, J. S. Wang¹, H. W. Wang³, W. D. Tian³, X. Q. Yu¹, L. Y. Zhang¹^,2, L. Li¹^,2, Y. Y. Yang¹^,2, P. Ma¹, X. H. Zhang¹, J. Su⁴, E. T. Li⁴, Z. G. Hu¹, Z. Y. Guo¹, X. Xu¹^,2, X. H. Yuan¹, W. Lu¹^,2, Y. H. Yu¹, Y. D. Zang¹^,2, S. W. Ye¹^,2, R. P. Ye¹^,2, J. D. Chen¹^,2, S. L. Jin¹^,2, C. M. Du¹^,2, S. T. Wang¹^,2, J. B. Ma¹, L. X. Liu¹^,2, Z. Bai¹^,2, X. Q. Li⁵, X. G. Lei¹, Z. Y. Sun¹, Y. H. Zhang¹, X. H. Zhou¹ and H. S. Xu¹

¹ Institute of Modern Physics, Chinese Academy of Sciences (CAS), 730000, Lanzhou, China
² Graduate School of Chinese Academy of Sciences, 100049, Beijing, China
³ Shanghai Institute of Applied Physics (SINAP), Chinese Academy of Sciences, 201800, Shanghai, China
⁴ China Institute of Atomic Energy (CIAE), P.O. Box 275(46), 102413, Beijing, China
⁵ School of Physics and State Key Laboratory of Nuclear Physics and Technology, Peking University, 100871, Beijing, China

^* e-mail: jianjunhe@impcas.ac.cn

Received: 3 November 2010
Revised: 28 March 2011
Accepted: 27 April 2011
Published online: 30 May 2011

Abstract

The stellar ¹⁴O (α, p) ¹⁷F reaction is thought to be one of the most important breakout reactions from the Hot CNO cycles into the rp-process in Type I X-ray bursters. In the present work, the properties of proton resonances in ¹⁸Ne have been investigated efficiently by utilizing a technique of proton resonant elastic scattering with a ¹⁷F radioactive-ion (RI) beam and a thick proton target. A 4.22 MeV/nucleon ¹⁷F RI beam, which was produced via a projectile-fragmentation reaction and experiencing a series of energy degradation, was separated by a Radioactive Ion Beam Line in Lanzhou (RIBLL) and bombarded a (CH₂)_n target. Energy spectra of the recoiled protons were measured by two sets of ΔE-E silicon telescope at center-of-mass scattering angles of θ _c.m. ≈ 175° ± 5°, θ _c.m. ≈ 152° ± 8°, respectively. Several proton resonances in ¹⁸Ne were observed, and their resonant parameters have been determined by an R-matrix analysis of the differential cross-sections. A doublet structure around 7.10 MeV has been identified and thought to be one state at 7.05 MeV (2⁺) and another one at 7.12 MeV (4⁺). The presently calculated total reaction rates of ¹⁴O (α, p) ¹⁷F are, at least, a factor of 1.2 ∼ 1.9 larger than the previous ones in a temperature region of 1.7 ∼ 3.0 GK mainly owing to the contribution from the 7.05 MeV (2⁺) state. This result implies that this breakout reaction may play a more important role than previously expected.