Lifetime measurements of excited states in N=50 nuclei using doppler shift attenuation method

This PhD thesis is focused on the lifetime measurements of excited states in 94Ru nucleus using the Doppler Shift Attenuation Method (DSAM). 94Ru is a semi-magic (N = 50) nucleus with a proton number 44 and neutron number 50. Excited states in 94Ru have been obtained in the 58Ni(40Ca,4p)94Ru∗ fusion-evaporation reaction at the GANIL accelerator facility. The EXOGAM germanium detector array has been used to measure γ-rays emitted from the compound nucleus. The fusion products corresponding to different reactions were selected using the DIAMANT CsI(Tl) charged particle detector system and the NEUTRON WALL liquid scintillator detector array. Lifetimes of several excited states in the 94Ru nucleus have been measured using LINESHAPE package. When the residual nuclei were decelarating in the thick 58Ni target, we observed the lineshapes which has Doppler effect on the lower energy part with respect to the centroid of the peak. In this study, we managed to get lifetimes of 8 excited states which are belong to 13+, 14+, 15+, 16+, 17+, 18+, 19+ and 20−. Within these 8 excited states, the lifetimes for 15+, 16+, 17+, 19+ and 20− excited states were measured for the first time. The obtained B(M1) and B(E2) transition probabilities from the lifetime values are compared with results of Large Scale Shell Model (LSSM) calculations to check the consistency between the experiment and theory.