New measurements of the astrophysicalSfactor for12C(p,γ)

Abstract

New measurements of differential and total cross sections for the 12 C(p, γ ) 13 N reaction have been made at beam energies of E p = 354, 390, 460, 463, 565, 750, and 1061 keV. Analysis of the astrophysical S factor S(E) for the 12 C(p, γ ) 13 N reaction at low energies and of the reaction rates has been carried out within the R-matrix approach by using the previously measured nuclear vertex constant (or the respective asymptotic normalization coefficient) for the virtual decay 13 N → p + 12 C to fix the direct capture part of the amplitude in S(E). It is demonstrated that the R-matrix approach, using the measured asymptotic normalization coefficient, can be employed as an ideal tool, minimizing the uncertainties associated with a calculation of the direct capture cross section of the 12 C(p, γ ) 13 N reaction at extremely low energies. New information on the proton and γ width for the first excited state of 13 N is obtained.

Determination of the 12C(p, γ)13N reaction rates from the 12C(7Li,6He)13N reaction

“…The S (E) factor at 25.0 keV is found to be (1.87 ± 0.13) keV b. The result is consistent with that of (1.75 ± 0.22) keV b obtained by Burtebaev et al [12], and slightly higher than the earlier values of (1.45 ± 0.20) keV b, (1.54 ± 0.08) keV b and (1.33 ± 0.15) keV b reported in refs. [9][10][11].…”

“…[42] and the references therein. Very recently, Burtebaev et al [12] measured the cross sections of the 12 C(p, γ) 13 N reaction at beam energies E p = 354, 390, 460, 463, 565, 750, and 1061 keV. They obtained ANC( 13 N) = 1.72 fm −1/2 , Γ γ 1 = (0.65 ± 0.07) eV and Γ p 1 = (35.0 ± 1.0) keV by fitting their experimental data with R-matrix approach.…”

“…= 70 keV [6][7][8][9][10][11][12][13] since 1950. However, an obvious discrepancy exists in the experimental *Corresponding author (email: zhli@ciae.ac.cn) †Contributed by LIU WeiPing data at the lower energies.…”

S-Factor measurement of the12C(p,γ)13N reaction in inverse kinematics

“…Also recent data for the astrophysical S-factor exists only for energies down to E cm ≥ 300 keV [7].…”

Cross section measurement of the astrophysically important O17(p,γ)F18Gyürky1, Ornelas2, Fülöp3 et al. 2017Phys. Rev. C11060View full textAdd to dashboardCite

“…From its decay rate it was identified as 13 N produced by the 12 C(p,γ ) 13 N reaction on carbon impurity of the target. This identification was also supported by the fact that such a deviation from the pure 18 F decay was observed mostly around 500 keV proton energy where the 12 C(p,γ ) 13 N reaction has high cross section due to a broad resonance at about 420 keV [21]. In such cases roughly the first one hour of the counting was omitted from the analysis.…”