Measurement of the Ne18(α,p 0)Na21 reaction cross section in the burning energy region for x-ray bursts

Abstract

The Ne18(α,p)Na21 reaction provides one of the main HCNO-breakout routes into the rp process in x-ray bursts. The Ne18(α,p 0)Na21 reaction cross section has been determined for the first time in the Gamow energy region for peak temperatures T∼2GK by measuring its time-reversal reaction Na21(p,α)Ne18 in inverse kinematics. The astrophysical rate for ground-state to ground-state transitions was found to be a factor of 2 lower than Hauser-Feshbach theoretical predictions. Our reduced rate will affect the physical conditions under which breakout from the HCNO cycles occurs via the Ne18(α,p)Na21 reaction. © 2012 American Physical Society.