First observation of excited states in 197At: the onset of deformation in neutron-deficient astatine nuclei
M.B. Smith1 - R. Chapman1 - J.F.C. Cocks2 - O. Dorvaux2 - K. Helariutta2 - P.M. Jones2 - R. Julin2 - S. Juutinen2 - H. Kankaanpää2 - H. Kettunen2 - P. Kuusiniemi2 - Y. Le Coz3 - M. Leino2 - D.J. Middleton1 - M. Muikku2 - P. Nieminen2 - P. Rahkila2 - A. Savelius2 - K.-M. Spohr1
1 Department of Electronic Engineering and Physics, University of Paisley, High
Street, Paisley PA1 2BE, UK
2 Accelerator Laboratory, Department of Physics, University of Jyväskylä, FIN-40351
Jyväskylä, Finland
3 DAPNIA/SPhN CEA-Saclay, France
Received: 8 January 1999 Communicated by B. Herskind
Abstract
Excited states in the Z = 85 nucleus 197At have been
identified for the first time using the recoil-decay-tagging (RDT) technique.
The excitation energy of these states is found to be consistent with the
systematics of neutron-deficient astatine
nuclei and with theoretical calculations
indicating that the nucleus may be deformed in its ground state.
PACS
23.20.Lv Gamma transitions and level energies -
27.80.+w 
Copyright Springer-Verlag
