The proton-proton momentum correlation functions $\left[C_{pp}\left(q\right)\right]$ for the kinematically complete decay channels ${}^{23}\mathrm{Al}\to p+p+{}^{21}\mathrm{Na}$ and ${}^{22}\mathrm{Mg}\to p+p+{}^{20}\mathrm{Ne}$ have been measured at the RIKEN RI Beam Factory. From the very different correlation strength of $C_{pp}\left(q\right)$ for ${}^{23}\mathrm{Al}$ and ${}^{22}\mathrm{Mg}$, the source size and emission time information were extracted from the $C_{pp}\left(q\right)$ data by assuming a Gaussian source profile in the correlation function calculation code (crab). The results indicated that the mechanism of two-proton emission from ${}^{23}\mathrm{Al}$ was mainly sequential emission, while that of ${}^{22}\mathrm{Mg}$ was mainly three-body simultaneous emission. By combining our earlier results of the two-proton relative momentum and the opening angle, it is pointed out that the mechanism of two-proton emission could be distinguished clearly.

• Received 6 August 2016
• Revised 11 September 2016

DOI:https://doi.org/10.1103/PhysRevC.94.044621