Study of the¹⁸⁷W states excited in the (n, γ) reaction

A singles γ-ray spectrum and a spectrum of summed amplitudes of coinciding pulses (SACP) were measured in the¹⁸⁶W(n, γ)¹⁸⁷W reaction experiment on the thermal neutron beam. It was for the first time that the data on¹⁸⁷W γ-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 of¹⁸⁷W 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 wave functions of compound and intermediate states.