Use of a microwave delay line to reduce the dead time in electron spin echo envelope spectroscopy

Echo envelope spectrometry, a method for obtaining the electron–nuclear superhyperfine spectrum by transforming the electron spin echo decay envelope into the frequency domain, is limited in its effectiveness by the presence of an appreciable dead time following the microwave transmitter pulses. We describe here a simple passive addition to the microwave circuit which can reduce the dead time by 1.5:1. The performance of an electron spin echo spectrometer with and without this accessory is compared.