Level and decay scheme studies in /sup 92/Zr and /sup 94/Zr via (n,n'. gamma. ) reactions

Measurements of (n,n'..gamma..) excitation functions were made for incident neutron energies from 2.2 to 3.7 MeV. For /sup 92/Zr, 51 transitions from 26 levels through 3472.0 keV excitation energy were observed. The /sup 94/Zr study of 20 levels through 3361.2 keV excitation energy produced 28 observed ..gamma.. rays, 12 of which were previously unidentified. Angular distributions were measured at 3.2 and 3.7 MeV bombarding energies for 24 and 39 transitions respectively in /sup 92/Zr and at 3.1 MeV for 18 transitions in /sup 94/Zr. Two new levels were discovered in /sup 92/Zr at 2903.8 and 3407.9 keV. A previously reported ambiguity involving 2/sup +/ and 4/sup +/ levels in /sup 94/Zr has been resolved, revealing a 4/sup +/ level at 2329.0 keV and a 2/sup +/ level at 2365.4 keV. New levels were found in this isotope at 2507.6, 2698.0, 2825.2, and 2859.8 keV. Six unique spin or spin-parity assignments, based only on the present work, were made in /sup 92/Zr(E/sub x/ in keV, J/sup ..pi../): 2339.0, 3; 2485.1, 5; 2742.6, 4; 2903.8, 0; 3056.5, 2; 3370.9, 1; and three in /sup 94/Zr: 2365.4, 2; 2507.6, 3; 2603.7, (5). A 4/sup -/, 5/sup -/ excited proton doublet appears to havemore » been found in each of the isotopes at excitation energies comparable to those for the doublet in /sup 90/Zr. This suggests similar proton configurations for all three isotopes. Neutron inelastic scattering cross sections are in agreement with those from experiments employing neutron detection.« less