Determination of the static quadrupole moment of the 1.98-MeV 2+ state in 18O

The static quadrupole moment of the first 2+ state in 18O has been determined using reorientation effect in the Coulomb excitation of 18O projectiles. For constructive interference from the coupling through the second 2+ state, the values obtained are Q2+ = - (0.073 +- 0.027) e x b and B (E2, 0+ → 21+) = (0.004 53 +- 0.0025) e2 x b2. Our result for Q2+ strongly disagrees with a recent measurement [Q2+ = - (0.19 +- 0.02) e x b)] but is consistent with theoretical calculations [Q2 = (0.03 - 0.06) e x b]