Level structure of 87Sr from the 86Sr(n, γ) and 86Sr(d, p) reactions

Abstract

The γ-ray spectrum emitted after thermal neutron capture in 86Sr was studied at the ILL high flux reactor with pair- and intrinsic Ge spectrometers. 759 transitions were assigned to the reaction 86Sr(n, γ) 87Sr and 385 of them were placed into a 87Sr level scheme of 80 levels. This represents 90% of the observed intensity. The level energies were determined with a precision of better than 20 ppm; the neutron binding energy was determined to be 8428.16 (17)keV. In a second set of experiments high resolution particle spectra of the reactions 86Sr(d, p) 87Sr and 88Sr(d, t) 87Si were recorded at 20 MeV deuteron energy with the München Q3D spectrometer. These data were used to establish newly found levels and to differentiate between primary and secondary transitions in the (n, γ) data. The observed level densities and primary transition strengths are compared with statistical models.