Structure of high-spin states in 143Pm

Abstract High-spin states of 143 Pm have been studied in the reactions 141 Pr(α, 2n) 143 Pm and 143 Nd(d, 2n) 143 Pm by means of in-beam spectroscopy. The level scheme, spin and parity assignments are based on results obtained from singles γ-ray spectra, conversion electron spectra, prompt and delayed γ-γ coincidences, γ-ray angular distribution and linear polarization measurements. Positive- and negative-parity states with energies up to 4580 keV and spins up to 25 2 have been established including 22 new levels. For two nanosecond isomeric states the nuclear spin precession in an external magnetic field was observed providing the following g -factors: g( 11− 2 , 959.7 keV)=1.14(9), g( 15+ 2 , 1898.3 keV)=1.00(7). The experimental results are well understood by calculations which have been performed in the framework of the shell model (for positive-parity states of 11 valence protons above a Z = 50, N = 82 core) and of the cluster-vibration model (for 3 holes in a Z = 64, N = 82 core). In the case of positive-parity states no evidence for particle-core coupling could be found, while the negative-parity states could qualitatively be understood within the particle-core coupling picture.