High-efficiency spin-resolved and spin-integrated electron detection: Parallel mounting on a hemispherical analyzer

We have mounted a compact 25 kV mini-Mott spin polarimeter on a commercial high-throughput hemispherical electron analyzer with a double purpose: to m aximize the polarization detection and to preserve the original efficiency of the spectrometer in the spin-integrated measurements. We have thus repla ced the 16-anode microchannel-plate detector with a 12-anode microsphere-pl ate detector in parallel with a Rice University retarding Mott spin polarim eter. Passing from one detection mode to the other is quick and easy. The t ransfer optics from the analyzer exit slit to the scattering target of the polarimeter allows the full potential of both the electron analyzer and the spin detector to be exploited. The expected effective Sherman function (S- eff=0.17) and figure of merit (eta(0)congruent to 1.4 x 10(-4)) are found i n the spin-resolved mode, and only 25% of the original efficiency is lost i n the spin-integrated acquisitions. (C) 1999 American Institute of Physics. [S0034-6748(99)02111-5].