STUDY OF THE W-187 STATES EXCITED IN THE (N,GAMMA) REACTION

A singles gamma-ray spectrum and a spectrum of summed amplitudes of coinciding pulses (SACP) were measured in the W-186 (n, gamma) W-187 reaction experiment on the thermal neutron beam. It was for the first time that the data on W-187-gamma-transitions were obtained in the excitation energy region from 1500-2500 keV. The neutron binding energy was determined to be B(n) = 5467.25 (4) keV (statistical error only). In result the level scheme of W-187 was developed in the excitation energy interval 1 < E(f) < 3.4 MeV, which contained 105 levels with about 70 of them being identified for the first time. The experimental values for summed intensities of two-step cascades were established to exceed those predicted by the modern statistical theory (by 36 +/- 6%). This is explained by a considerable contribution of few-quasiparticle components to functions of compound and intermediate states.