Abstract:

An electron-gamma angular correlation arrangement using a lithium-drifted semiconductor counter as electron detector is presented. This was placed together with a field-effect transistor in a cylindrical rotating vacuum chamber cooled at a temperature of 200°K through a cold-finger system. Three scintillation counters set at right angles complete the system. Three coincidence circuits were used together with a routing system, in order to display three different electron-conversion spectra in memory subgroups of a multichannel analyzer. A resolution of 0.6% was obtained at 1 MeV, thus permitting the separation of the three main conversion lines of both cascades of 570 and 1064 keV from the decay of 207Bi. Electron-gamma coincidences at three different angles were simultaneously recorded in the particular case of the above cascades. Values of A2 coefficients for the three shells for both correlations are also presented. © 1969.