The component that electronically sorts energies of characteristic xrays is the:

• A. Xray tube
• B. Xray detector
• C. Multi-channel analyzer
• D. Computer

Answer: (C)

The multi-channel analyzer is the device that sorts characteristic X-ray energies. It works as a pulse-height analyzer: each detected X-ray photon produces an electrical pulse whose height is proportional to its energy. The MCA assigns each pulse to a channel (bin) corresponding to that energy and counts how many photons fall into each channel. This creates the energy spectrum (counts versus energy) used to identify and quantify elements. The X-ray tube provides the excitation, the detector converts photons to electrical signals, and the computer may display or store the spectrum, but the sorting by energy is performed by the multi-channel analyzer.