Isomeric states in $^{253}$No

A. Lopez-Martens (1) , K. Hauschild (1) , O. Dorvaux (2) , Ch. Briançon (1) , D. Curien (2) , P. Désesquelles (1) , B. Gall (2) , F. Khalfallah (2) , A. Korichi (1) , Marc Rousseau (2) , N. Rowley (2) , L. Stuttgé (2) , Ch. Theisen (3)

1 CSNSM - Centre de Spectrométrie Nucléaire et de Spectrométrie de Masse
2 DRS-IPHC - Département Recherches Subatomiques
3 DAPNIA - Département d'Astrophysique, de physique des Particules, de physique Nucléaire et de l'Instrumentation Associée

Isomeric states in 253No have been investigated by conversion-electron and gamma-ray spectroscopy with the GABRIELA detection system. The 31 micro second isomer reported more than 30 years ago is found to decay to the ground state of 253No by the emission of a 167 keV M2 transition. The spin and parity of this low-lying isomeric state are established to be 5/2+. The presence of another longer-lived isomeric state is also discussed.

Mots clés: noyaux lourds; spectrosocpie gamma et électrons de conversion; mesure de temps de vie

Domaines: Physique Nucléaire Expérimentale [nucl-ex]

A. Lopez-Martens, K. Hauschild, O. Dorvaux, Ch. Briançon, D. Curien, et al.. Isomeric states in $^{253}$No. European Physical Journal A, 2007, 32, pp.245-250. ⟨10.1140/epja/i2007-10391-8⟩. ⟨hal-00154333⟩