  Electron spin takes critical role in almost all novel phenomena discovered in
modern condensed matter physics (High-temperature superconductivity, Kondo
effect, Giant Magnetoresistance, topological insulator, quantum anomalous Hall
effect, etc.). However, the measurements for electron spin is of poor quality
which blocks the development of material sciences because of the low efficiency
of spin polarimeter. Here we show an imaging type exchange-scattering spin
polarimeter with 5 orders more efficiency compared with a classical Mott
polarimeter. As a demonstration, the fine spin structure of electronic states
in bismuth (111) is investigated, showing the strong Rashba type spin splitting
behavior in both bulk and surface states. This improvement pave the way to
study novel spin related phenomena with unprecedented accuracy.
