Measurements of X-ray photoelectron diffraction using high angular resolution and high transmission electron energy analyzer

We have developed an angle-resolving electron energy analyzer with a newly designed input-lens system. In this lens system, angle resolving is accomplished by use of a diffraction-plane aperture. Using this system, both high angular resolution (<0.1°) and high transmission are easily achieved in photoelectron diffraction measurements. In order to evaluate this analyzer, we measured the X-ray photoelectron diffraction (XPED) patterns from CaF₂(1 1 1) surface. The angular resolution is easily determined by the size of diffraction-plane aperture. By using the diffraction-plane aperture with the angular resolution of ±0.08° or ±0.04°, many fine structures of XPED patterns become to be clearly measured.