FIZIKA B 7 (1998) 1, 15-36

STUDY OF ¹⁹⁴Ir VIA THERMAL NEUTRON CAPTURE AND (d,p) REACTIONS

M. BALODIS, P. PROKOFJEVS, N. KRAMERE, L. SIMONOVA, J. BERZINS, T. KRASTA,
Nuclear Research Center, LV-2169 Salaspils, Latvia

R. GEORGII, T. von EGIDY, J. KLORA, H. LINDNER, U. MAYERHOFER, A. WALTER,
Physik-Department, E18, Technische Universität München, D-85748 Garching bei München, Germany

J. A. CIZEWSKI,
Rutgers University, Piscataway, NJ 08855, USA

G. G. COLVIN, H. G. BOERNER, P. GELTENBORT, F. HOYLER, S. A. KERR, K. SCHRECKENBACH,
Institute Laue-Langevin, F-38042 Grenoble, France

A. RAEMY, J. C. DOUSSE, J. KERN, W. SCHWITZ,
Physics Department, University of Fribourg, CH-1700 Fribourg, Switzerland

I. A. KONDUROV, YU. E. LOGINOV, P. A. SUSHKOV,
Petersburg Nuclear Physics Institute, 188350 Gatchina, Russia

S. BRANT, V. PAAR
Department of Physics, University of Zagreb, HR-10000 Zagreb, Croatia

and V. LOPAC
Department of Physics, Faculty of Chemical Engineering and Technology, University of Zagreb, HR-10000 Zagreb, Croatia

Received 28 August 1997; Accepted 11 May 1998

Levels of ¹⁹⁴Ir were studied using thermal neutron capture reaction. A pair spectrometer was used to measure the high-energy g-ray spectrum from thermal-neutron capture in enriched ¹⁹³Ir target over the energy range 4640 - 6100 keV. The low-energy g-radiation from the reaction was studied with crystal diffraction spectrometers, and conversion electrons were observed with magnetic spectrometers. The high-sensitivity measurements at the Grenoble reactor, evaluated for transition energies up to 500 keV, are compared with lower-sensitivity measurements at the Wuerenlingen and Salaspils reactors. The comparison helped to obtain reliable isotopic identification for a number of ¹⁹⁴Ir lines. The multipolarity admixtures for 29 g-transitions were determined on the basis of conversion lines from different electron subshells. Prompt and delayed g-g coincidences were measured using semiconductor and scintillation detectors. The ¹⁹³Ir(d,p) high-resolution spectra, observed with a magnetic spectrometer, are given. All these data contributed to establishing a detailed level scheme of ¹⁹⁴Ir. Additional data and the interpretation of the results in terms of current models will be presented in a forthcoming paper.

PACS numbers: 21.10-k, 23.20Lv, 27.80+w
UDC 539.163, 539.172

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