Measurement of B(E2↑) for ³⁶Ca

In a pair of experiments, the B(E2; 0⁺_g.s –>2⁺₁) was measured for ³⁶Ca. The first experiment measured a cross section for the Coulomb excitation of a ³⁶Ca beam where only gamma decays were detected. The second experiment measured the p/g branching ratio required as a correction to this cross section because the 2⁺₁ state of ³⁶Ca is above the proton separation energy. The corrected B(E2) was measured to be 131(20) e²fm⁴ and the proton branching ratio was measured to be 0.087(8). These values differ from those used in calculations that were previously employed in x-ray burst simulations. The B(E2) and branching ratio are needed to calculate the partial decay widths needed for the ³⁵K(p,γ)³⁶Ca reaction rate, a reaction which escapes the ³⁴Ar waiting point in the rp-process. The B(E2) is also used as a correction for collectivization in the method of mirror charge radii for determining L, the slope of the symmetry energy with denisty.