GAMMASPHERE+FMA : a journey beyond the proton drip-line.
The majority of experiments performed during the 2-year long stay of GAMMAS-PHERE at the Argonne National Laboratory aimed to study proton-rich nuclei far from the line of stability at and beyond the proton drip-line. A high reaction channel selectivity was required to assign in-beam {gamma}-ray transitions to weakly populated exotic nuclei in the presence of background from strong reaction channels. In many of the experiments this was achieved by using the Argonne fragment mass analyzer to separate heavy-ion fusion-evaporation reaction products from scattered beam and disperse them according to their mass-over-charge-state ratio. For medium mass and heavy a and proton emitters the Recoil-Decay Tagging method was implemented. In-beam {gamma}-ray transitions were observed in several proton emitters between Z=50 and Z=82. Among others, rotational bands were assigned to {sup 141}Ho and {sup 131}Eu. A quadruple deformation of {beta}=0.25(4) was deduced for the ground state in {sup 141}Ho from the extracted dynamic moment of inertia. Based on observed band crossings and signature splittings the 7/2{sup {minus}} [523] and 1/2{sup +}[411] configurations were proposed for the ground state and the isomeric state, respectively. Comparison with particle-rotor calculations indicates, however, that {sup 141}Ho may have significant hexadecapole deformation and could be triaxial.
- Research Organization:
- Argonne National Lab., IL (US)
- Sponsoring Organization:
- US Department of Energy (US)
- DOE Contract Number:
- W-31-109-ENG-38
- OSTI ID:
- 772113
- Report Number(s):
- ANL/PHY/CP-103549; TRN: US0102206
- Resource Relation:
- Conference: Nuclear Structure 2000 Conference, East Lansing, MI (US), 08/15/2000--08/19/2000; Other Information: PBD: 30 Nov 2000
- Country of Publication:
- United States
- Language:
- English
Similar Records
In-beam studies of proton emitters using the Recoil-Decay Tagging method
Shell Structure Beyond the Proton Drip Line Studied via Proton Emission from Deformed 141Ho