Half-life Measurement of the i 13 / 2 State in 20983 Bi

This proposal is an extension of a previous one entitled “Lifetime Measurements of Single Particle States in 209 83 Bi”, which was awarded 10 days of beam-time at the PAC meeting in March 2012. The aim is to study the influence of the single-particle and collective modes in 209 83 Bi, and in July 2012 we measured the half-life of the i13/2 level at Ex=1.608 MeV as 150±25 ps. However this is not sufficiently accurate to give a unique interpretation of the level. We now request to complete this study and extend our findings from the previous experiment in two steps; by using the fast timing, ROSPHERE array of cerium-doped lanthanum bromide (LaBr3(Ce)) and high-purity germanium (HPGe) detectors to acquire more statistics to reduce the uncertainty in the half-life, and to perform an angular distribution measurement in order to determine the B(E3) and B(M2) mixing ratio of the depopulating transition to the 9 2 − level.