Z. Phys. A - Hadrons and Nuclei 338,471-472 (1991) "'~ Hadrons ffir Physik A and Nuclei 9 Springer-Verlag 1991 Short note Superdeformed bands in 19STI F. Azaiez 1, W.H. Kelly 1b, W. Korten 1, M.A. Deleplanque 1 F.S. Stephens 1, R.M. Diamond 1, ,I.E. Draper A.O. Macchiavelli 1d, E. Rubel l c, j. de Boer 1e, M. Rohn 1r J.A. Becker 2, E.A. Henry e, M.J. Brinkman 2r, S.W. Yates eg, A. Kuhnert e, and T.F. Wang 2 1 Lawrence Berkeley Laboratory, Berkeley, CA 94720, USA 2 Lawrence Livermore National Laboratory, Livermore, CA 94550, USA Received February 22, 1991 lc Abstract: Two superdeformed (SD) bands have been found and assigned to 195T1 on the basis of excitation function and cross bombardment results. The two bands are almost identical in transition energies to those observed in 193T1. They are signature partners with a splitting, presumably due to the proton i13/2 (f~=5/2) orbital, characteristic of all known SD bands in the thallium isotopes. Their alignments relative to the 193T1 bands were found to be zero. PACS" 23.20.Lv, 25.70.-z, 27.80.+w In the mass 190-region an unexpectedly large number of SD bands has been found to have nearly "identical" transition energies [1]. The majority of the SD bands in the mercury isotopes exhibit transition energies similar or related to those of a "reference" band in 192Hg [1]. In the case of the thallium isotopes, all six SD bands in 194T1 a Permanent address: CEN-BG, IN2P3, Le Haut-Vigneau--33170 Gradignan, France. b Permanent address: Department of Physics and Astronomy, Iowa State University, Ames,IA 50011. c Permanent address: University of California-Davis, CA 95616. d On leave from Comision Nacional de Energia Atomica 1429 Buenos Aires, Argentina. e Permanent address: Universitat Munchen, Am CoulombwaU 1, D-8046 Garching, F. R. Germany f Permanent address: Rutgers University, New Brunswick, NJ 08903 g Permanent address: Department of Chemistry, University of Kentucky, Lexington, KY 40506 have been reported [2] to be similar to the two bands in 193T1 [3]. Here we report the observation of two SD bands in 195T1 which also are similar to the two "reference" bands in 193T1. The experiment was carried out at the LBL 88-Inch Cyclotron, using HERA which consists of a central BGO ball of 40 elements surrounded by 20 Compton- suppressed Ge spectrometers. Thallium isotopes were produced in two different experiments. In the first, the reaction 180 + 181Ta at beam energies of 95-, 100- and 104-MeV was used to populate the A=193, 194 and 195 thallium isotopes. In a second experiment, the reaction 15N + 186W at beam energies of 90- and 95-MeV was used to populate 195T1 and 196T1 isotopes. The targets consisted of three 0.5 mg/cm 2 self-supporting foils stacked together. Approximately 200 million events per beam energy were recorded on tape with the condition that at least three Ge detectors fired or two Ge detectors together with at least six central ball detectors fired. Searches for SD bands were made, using gated projections from double-coincidence matrices with various multiplicity and total-energy requirements. In addition to the six SD bands in 194T1 observed in the data from the two highest 180 beam energies (100 and 104 MeV) [2], two other SD bands have been identified in the same 180 data but only at 95-MeV beam energy. For each band a sum of single-gated spectra with a condition that at least I0 elements from the BGO ball had fired, are displayed in Figure 1. Under the multiplicity condition outlined above, band 1 was found to represent about 0.5 %