Cylindrical Mirror Analyzer (CMA)

• The electrons ejected will pass through a device called a CMA.

• The CMA has two concentric metal cylinders at different voltages.

• One of the metal cylinders will have a positive voltage and the other will have a 0 voltage. This will create an electric field between the two cylinders.

• The voltages on the CMA for XPS and Auger e^- s are different.

• When the e^- s pass through the metal cylinders, they will collide with one of the cylinders or they will just pass through.

• If the e^- 's velocity is too high it will collide with the outer cylinder
• If is going too slow then will collide with the inner cylinder.
• Only the e^- with the right velocity will go through the cylinders to reach the detector.

• With a change in cylinder voltage the acceptable kinetic energy will change and then you can count how many e^- s have that KE to reach the detector.