High spin states of 57Co have been studied with the 40Ca(20Ne, 3p) and 55Mn(α, 2n) reactions at 68 MeV and 25 MeV respectively. The first measurement used γ-γ-recoil coincidences with the OSIRIS γ-spectrometer and the Recoil Filter Detector (RFD). The RFD measured the velocity vector of the fusion evaporation residues; therefore an event by event Doppler correction could be applied with a significant improvement for the γ-energy resolution. The analysis of the γ-γ-recoil coincidence spectra resulted in 43 new γ-transitions of energies between 300 keV and 3300 keV that are assigned to 57Co and established 25 new excited states. Also a DCO analysis has been performed on the present data, however it does not lead to an unambiguous spin assignment for most states as the measured DCO-ratio is often compatible with different spin combinations. The reaction 55Mn(α, 2n) was studied with a compact setup of two Gedetectors. Singles γ- and γ-γ-coincidence spectra were measured. Mainly low spin states were populated, and 26 previously known γ-transitions as well as 21 excited states of 57Co have been confirmed. In this contribution results are presented on 57Co, the nucleus with two neutrons and one proton hole.
|Number of pages||4|
|Journal||Acta Physica Polonica B|
|Publication status||Published - 1996|