Eur. Phys. J. A (2009) 40: 127-130
https://doi.org/10.1140/epja/i2009-10756-y

Letter

Assignment of levels in ²⁰⁸Fr and 10^- isomers in the odd-odd isotones ²⁰⁶At and ²⁰⁸Fr

¹ Department of Nuclear Physics, R.S. Phys. S.E, Australian National University, ACT 0200, Canberra, Australia
² Department of Physics, Australian National University, ACT 0200, Canberra, Australia
³ Department of Physics, University of Jyväskylä, P.O. Box 35, (YFL) FIN-40014, Jyväskylä, Finland
⁴ Nuclear Physics Research Division, RIKEN Nishina Center, 2-1 Hirosawa, 351-0198, Wako, Saitama, Japan

Received: 12 January 2009
Revised: 1 March 2009
Accepted: 10 March 2009
Published online: 22 March 2009

Abstract

Excited states in ²⁰⁸Fr have been identified using the ¹⁹⁷Au(¹⁶O, 5n)²⁰⁸Fr reaction and a variety of time-correlated -ray and conversion electron spectroscopic techniques. Transitions above and below a = 623(16) ns 10^- isomer are placed in the level scheme. This isomer is analogous to that observed in the odd-odd isotone ²⁰⁶At for which additional spectroscopic information is also obtained, including a precise lifetime of = 1173(30) ns. The -rays assigned to ²⁰⁸Fr are the same as the main transitions erroneously assigned to ²⁰⁹Fr in previous work.