ReactionAr36(p,γ)37

Abstract

The reaction Ar(p, y) K has been measured in the proton energy range of E~= 0.32-0.93 MeU. A new resonance was found at E& =321 keU. We have measured the branching ratios and the resonance strength.The stellar reaction rates which are dominated by this resonance for temperatures T=0.07-0.9 GK are calculated. Network calculations have been performed to investigate the influence of the new stellar rates on the time evolution of the Ar abundance during explosive H burning. PACS number(s): 25.40.Lw, 27.30.+t, 95.30.Cq

Proton‐induced Thermonuclear Reaction Rates for A = 20–40 Nuclei

“…However, the contribution of this state to the reaction rate is negligible. The direct capture contribution was adopted from Iliadis et al (1992b). Our recommended total rate deviates from the previous results of Iliadis et al (1992b) by about 20%, mainly because of the normalization of resonance strengths in the present work according to the values listed in Table 1.…”

“…The direct capture contribution was adopted from Iliadis et al (1992b). Our recommended total rate deviates from the previous results of Iliadis et al (1992b) by about 20%, mainly because of the normalization of resonance strengths in the present work according to the values listed in Table 1. In the temperature regions T \ 0.07 GK, T \ 0.07È1.0 GK and T [ 1.0 GK our total reaction rates are uncertain by 35%, 15% and 8%, respectively.…”

“…At lower temperatures, the uncertainties amount to up to 8 orders of magnitude, mainly because the adopted experimental upper limits of in the energy region keV are rather uc pa E p \ 550È860 high. Note that the 36Ar level at keV corresponding to keV was accidentally omitted E x \ 8887 E R cm \ 381 in Table 36f of Endt (1998 Iliadis et al 1992b ;Iliadis et al 1993b). The measured strengths have been normalized by using the results listed in Table 1.…”

“…The measured strengths have been normalized by using the results listed in Table 1. For the level at keV, corresponding to keV, only an upper limit for has been E x \ 2285 E R cm \ 428 uc pc measured (Iliadis et al 1992b). However, the contribution of this state to the reaction rate is negligible.…”

Explosive Hydrogen Burning

“…Because these reactions are char acterized by low Q-values and low level densities in the compound nucleus, they are expected to be dominated by the contributions of isolated resonances. These reactions have all been measured by bom barding a solid target with a high-intensity proton beam (65,104,105) and the reaction rate has been determined accurately from the mea sured excitation function.…”