Investigation of the high-spin structure of 200,202Pb

The yrast structure of 200,202Pb was studied using the 200,202Hg(α, 4n) reactions at Eα = 53 MeV. The de-excitation of the excited states was studied using conventional in-beam γ-ray spectrosopic methods including γγ(t) coincidence, pulsed-beam γ(t) and angular distribution measurements. Levels with a possible spin up to 21 ħ were observed in both nuclei. In addition to the previously known isomers, a 16+ isomeric state at 4069.8 + δ keV with T 1 2 = 5(1) ns and a 19 − isomeric state at 4932.0+ e keV with T 1 2 = 67 (5) ns were observed in 200Pb. A new 19−isomeric state at 5241.9 + S keV with T 1 2 = 107 (5) ns was also observed in 202Pb. The g-factors of the isomeric states were determined using the time differential perturbed angular distribution technique and the results are g = −0.094 (7) and g = −0.099 (3) for the 19− states in 200Pb and 202Pb, respectively. The measured g-factors indicate a predominantly four-quasineutron configuration ν f 5 2 −1 i 13 2 −3 for the 19− isomeric states.