Electron Spin Resonance Spectroscopy:

Figure 36.01 depicts the block diagram of EPR spectrometer. The radiation source is usually called a Klystron, which are vacuum tubes known to be stable high power microwave sources. They have low-noise and thus give high sensitivity.

A majority of EPR spectrometers operate at approximately 9.5 GHz. The radiation may be incident on the sample continuously or pulsed. The sample is placed in a resonant cavity which is located in the middle of an electromagnet.

Figure 36.01: Block diagram of EPR spectrometer.