Electron Spin Echo Spectrometer and Measurements

Our ESE spectrometer was first built in 1982, and since then has been continuously modified for improvement. The basic construction and characteristics of the spectrometer have already been reported in detail elsewhere [14, 15]. The present status will be briefly described here. 

The phase relaxation curve was recorded by monitoring the peak intensity of the two-pulse ESE signal as a function of the time interval between the two microwave pulses, x. The relative shape of an ESE signal is determined by the free induction decay, so that it does not depend on x. The phase relaxation takes place between the time of the excitation and the observation, so that t2 = 2x is the time for the phase relaxation. The longitudinal relaxation also causes the decrease in the ESE intensity. However this effect is negligible because the rate of the longitudinal relaxation in solids is usually more than two orders of magnitude lower than the phase relaxation rate. 

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