Rotational band structures in doubly oddPm138

Abstract

High-spin states in the doubly odd nucleus '"Pm have been studied via gamma-ray spectroscopic methods following the " Cd("A1,5ny) heavy-ion fusion-evaporation reaction. Several rotational bands have been populated in the nucleus. The yrast cascade is based on two signature components of the mh]l&2vh], &2 configuration. A sideband was observed, which is probably based on the sr[413]i+Svh"~i configuration. Similar rotational bands built on these configurations have been observed in the neighboring doubly odd " Pr and ' Pm nuclei. An additional AI=2 band structure, not observed in these other nuclei, has also been populated. At low rotational frequencies, this band is possibly based on the ith"~&IIv[400] -, '+ configuration. At a frequency fico 0 3-1 M. eV it is crossed by a band based on the favored signature of the~h»z& vi]3~, configuration with an accompanying gain in alignment of -6A.Recently at Stony Brook, the doubly odd ' La, Pr, and ' ' Pm nuclei have been studied. ' ' ' ' The present paper presents the results for Pm which is the heaviest of these nuclei. No information regarding the high-spin structure of ' Pm was avai1able before this work was carried out. The results are interpreted using cranked shell-model calculations. ' A preliminary report of the work has been presented. '

High-spin structures in the139Pr nucleus

“…This band should belong to a double decoupled band which was also observed in the neighboring odd-odd 134,136 Pr [9,34], 138,140 Pm [20,35], and N = 80 odd-A 141 Pm [21]. The origin of this band structure is the configuration for a valence neutron or valence proton including a low-orbital, so a large signature splitting between the favored and unfavored constituents occurs [34].…”

Semidecoupled band structure in odd-oddLa134andPrOliveira1, Emediato2, Cybulska3 et al. 1992Phys. Rev. C15020View full textAdd to dashboardCite

“…'Present address: Lawrence Berkeley Laboratory, Nuclear Science Division 70A-3307, 1 (99%) and Te (98.7%) powder compressed onto a lead foil. In the case of the~3 4La nucleus, the gamma rays from the i2sTe(ioB, 4n) reaction were identified through comparison with the (er, 3n) reaction [7].…”

“…Total Routhian calculations performed with the Vz, parameter[12] of -1 MeV for the z [413]2 vhtqIq configuration show two competing equilibrium deformations, one at p -70' and another near y = O'. However an oblate shape (7 -70') is unlikely as it would mean decoupling of the neutron implying strong F2 transitions, not observed experimentally.…”

Decay of aπh11/2⊗νh11/2microsecond isomer inRigby1, Cullen2, Mason3 et al. 2008Phys. Rev. C11020View full textAdd to dashboardCite

“…The N = 77 odd-odd nuclei, 138 61 Pm [19], 140 63 Eu [20], 142 65 Tb, and 144 67 Ho [6,20], all have J π = 8 + isomers decaying by low-energy E1 transitions to J π = 7 − states (174 keV in 138 Pm, 37 keV and 98 keV in 140 Eu, 37 keV in 142 Tb, and at 56 keV in 144 Ho). In the N = 73 odd-odd nucleus, 134 61 Pm 73 , a similar yrast band structure has 034304-4 2 .39 × 10 5 2.6(2) × 10 7 10 E1…”