Coulomb Excitation of Radioactive $^{21}$Na with TIGRESS and BAMBINO

The first experiment to use modules of the TRIUMF-ISAC Gamma-Ray Escape-Suppressed Spectrometer (TIGRESS) with an accelerated radioactive ion beam has been performed successfully, using the ISAC facility at TRIUMF. The low-energy structures of the five-particle nuclei ${}^{21}$Na and ${}^{21}$Ne were examined, in order to test model predictions of these deformed nuclei. For $^{21}$Na, the $\pm$86\% uncertainty on the previously accepted B(E2) value, resulting from the dominance of M1 decay in these nuclei, has made comparison difficult. Beam particles were accelerated to 1.7~MeV/A, and Coulomb excited in a $^{nat}$Ti target. Recoiling projectile and target ions were detected by the BAMBINO segmented silicon detector, while $\gamma$-ray yields were determined using two TIGRESS detectors perpendicular to the beam axis. For $^{21}$Na and $^{21}$Ne, Coulomb excitation from the 3/2$^{+}$ ground state to the 5/2$^{+}$ state was observed. Strongly enhanced B(E2) values were determined, which will be compared with the simplest quadrupole rotor model, and shell model predictions.