Reflective Electron Energy Loss Spectroscopy (REELS)

REELS refers to the measurement of specific energy losses suffered by a Primary Electron (PE) travelling through a surface or inside a solid target.

By bombarding the surface with monoenergetic electrons and measuring the energy distribution of the reflected electrons, information about excitation of vibrational and plasmon states can be obtained.

Since hydrogen in any compound does not have a core electron so will not produce a core photoelectron peak, REELS is useful as a complimentary technique to XPS in the semi-quantitative determination of hydrogen at a sample surface.