Trends in EPR Technology

Abstract

A personal view of trends in EPR technology is presented. It is unlikely that the fundamental structure of the field will change, but it will be strongly influenced by the rapid increase in computer power, digital storage, and signal processing capability. In the author's laboratory current themes are resonator enhancement by electromagnetic field finite element modeling, analysis of noise, and digital detection and acquisition of data at multiple microwave frequencies. Some trends foreseen are (1) optimization of resonators for ultra-small samples; (2) step-recovery pulse EPR in which the initial conditions may be established by a step in some experimental condition such as light level or nuclear frequency irradiation; (3) blurring of the distinction between pulse and CW EPR as temporal changes in the resonant condition of a " CW " measurement are changed in times of the order of spin relaxation times; and (4) increased use of ELDOR.