Al reaction*

Type I X-ray burst (XRB) nucleosynthesis involves processes such as the triple-α reaction, the rp-process, and the (α,p) process. The dominant (p,γ) nucleosynthesis flow in XRBs halts at several waiting point nuclei such as ²²Mg, ^24-26Si, ^28-30S and ³⁴Ar due to (p,γ)-(γ,p) equilibrium. The XRB nucleosynthesis flow can bypass these waiting points via (α,p) reactions. However, the present uncertainties in the relevant (α,p) reaction rates at these waiting points hinder the ability to accurately predict the light curve and ash composition of XRBs. For these waiting point nuclei, the ²²Mg(α,p)²⁵Al reaction has been identified as an important reaction bypassing the waiting points for XRB nucleosynthesis. Thus, it is crucial to constrain the reaction rate of the ²²Mg(α,p)²⁵Al reaction at astrophysical energies. To this end, we have performed a direct measurement of the ²²Mg(α,p)²⁵Al reaction cross section in inverse kinematics using a ²²Mg beam from the RAdioactive Ion SeparatOR (RAISOR) and the MUlti-Sampling Ionization Chamber (MUSIC) at Argonne National Laboratory. Preliminary results from this measurement will be discussed.