• A monoenergetic x-ray beam emits photoelectrons from the from the surface of the sample.

• The X-Rays either of two energies :

• AlKα (1486.6eV)
• MgKα (1253.6 eV)

• The x-ray photons The penetration about a micrometer of the sample

• The XPS spectrum contains information only about the top 10-100 Å Ǻ of the sample.

• Ultrahigh vacuum environment to eliminate excessive surface contamination.

• Cylindrical Mirror Analyzer (CMA) measures the KE of emitted e^-s.

• The spectrum plotted by the computer from the analyzer signal.

• The binding energies can be determined from the peak positions and the elements present in the sample identified.