2)

a) What are two main functions of an ion gun in an AES and XPS system?

b) What are the differences between electron energy analyzers for AES and XPS? Why?

c)

In XPS, we need to detect energy shifts of 0.1 eV at energy levels up to 1500 ev. For an energy

analyzer with the energy resolution limit, AE = 5.3x10³, does a pass energy of 10 eV satisfy

the requirement?