Electric quadrupole moment of the neutron-rich ~(33)Al

摘要

The nuclear electric quadrupole moment (Q moment) of the neutron-rich nucleus 33Al (I = 5/2, T1/2 = 41 ms) has been measured by the β-ray detected nuclear quadrupole resonance (β-NQR) method for the first time. The 33Al nucleus is considered to be on the border of the island of inversion within which a significant intrusion of the pf orbits occurs across the N = 20 shell gap and the intrusion causes an anomalous enhancement of the Q moment. Polarized 33Al nuclei were produced from 36S (77.5MeV/u) beams through the fragmentation process and separated by LISE fragment separator at GANIL. The 33Al nuclei were implanted into a Al2O3 single-crystal plate and the β-NQR spectrum was successfully obtained.