Notizen: Cross Polarization in Electron Nuclear Double Resonance by Satisfying the Hartmann-Hahn Condition

The polarization of electronic spins S is transferred to nuclear spins I by cross relaxation in an electron nuclear double resonance experiment. The cross relaxation becomes very efficient with a time constant T cr of about 0.5 microseconds if the Hartmann-Hahn condition is satisfied for electronic spins S spin-lock ed to the microwave field B 1,S in the rotating frame and for proton spins / in the static magnetic field B 0 .