Remnants of spherical shell structures in deformed nuclei; The Impact of an = 64 neutron subshell closure on the structure of 90 gadolinium nuclei

変形核で球殻構造の残留; 90ガドリニウム原子核の構造に=64中性子サブシェル閉鎖の影響

Ross, T. J.*; Hughes, R. O.*; Beausang, C. W.*; Allmond, J. M.*; Angell, C.; Basunia, M. S.*; Bleuel, D. L.*; Burke, J. T.*; Casperson, R. J.*; Escher, J. E.*; Fallon, P.*; Hatarik, R.*; Munson, J.*; Paschalis, S.*; Petri, M.*; Phair, L. W.*; Ressler, J. J.*; Scielzo, N. D.*

Ross, T. J.*; Hughes, R. O.*; Beausang, C. W.*; Allmond, J. M.*; Angell, C.; Basunia, M. S.*; Bleuel, D. L.*; Burke, J. T.*; Casperson, R. J.*; Escher, J. E.*; Fallon, P.*; Hatarik, R.*; Munson, J.*; Paschalis, S.*; Petri, M.*; Phair, L. W.*; Ressler, J. J.*; Scielzo, N. D.*

Odd-mass gadolinium isotopes around = 90 were populated by the () reaction, utilizing 25-MeV protons, resulting in population of low-spin quasi-neutron states at energies near and below the Fermi surface. Systematics of the single quasi-neutron levels populated are presented. A large excitation energy gap is observed between levels originating from the , and spherical parents (above the = 64 gap), and the (below the gap) indicating that the spherical shell model level spacing is maintained at least to moderate deformations.