Abstract: A method for prolonging the operation lifetime of klystron in EPR spectrometer was described. Based on this method, a severely degenerated klystron can be utilized for a time, so that the EPR spectrometer may operate continuously, as long as the operation state of the microwave bridge was tuned correctly and the power calibration level of the microwave power leveler was adjusted properly.

Key words: EPR spectrometer, Klystron, Microwave bridge, Microwave power lever