Development of X-eX spectrometer at KEK-PF-AR Original Research Article

An X-eX spectrometer has been developed to obtain the two-dimensional and three-dimensional electron momentum density (2D- and 3D-EMD) directly from experiment. The spectrometer is equipped with a time-of-flight energy analyzer to record the flight direction and the kinetic energies of the recoiled electrons, and a position sensitive photon detector to record the directions of the Compton scattered photons. The signals from the electron branch and those from the photon branch are processed in coincidence mode. The obtained 2D-EMD on the (100) plane in Si and the 3D-EMD on the [100] and the [111] axes are compared with the FLAPW theoretical results.