Measurement of the linear electric field effect in EPR using the spin echo method

Abstract

An apparatus is described which is designed to measure the linear electric field effect in EPR for amorphous samples such as those which are often encountered in biophysical studies. The apparatus is based on the electron spin echo method. It is capable of measuringg shifts ≃ 10−9 cm/V for samples with phase memory times ≃ 1 μsec. A brief general description of the electron spin echo apparatus is given, special attention being paid to those parts of the system developed specifically for the purpose of measuring the linear electric field effect. The influence of electric field homogeneity and of the pulse timing parameters on the measurements has been investigated in detail.