Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
Population distribution at thermal equilibrium for a general three-spin system (a). Saturation of the allowed EPR transitions for one of the dipolar coupled electrons (ω0S1) leads to negative enhancement (b). Saturation of the transition corresponding to the second electron (ω0S2) leads to positive enhancement (c).
