Oscillator Oscillation Level Detector Current Source Oscillation Level at fixed frequency ‘ν’ When No ESR Oscillation Level reduced when there is ESR absorption Detected DC Level No ESR Reduced DC On ESR Absorption hν=gβH No oscillations If the Current is increased from 0 to beyond resonance field, then, the field [ H t ] increases with time and causes resonance at resonance field value 2 1 hν=gβ H The role of a phase Φ shifter in the diagram would be explained in the succeeding slides CLICK to transit to next slide Φ Shifter HtHt

Z - Magnetization along the Field RF Pulse : π/2 pulse to flips the magnetization into xy plane Defocusing and signal decay Output from receiver coil - FID XY - Magnetization induces RF signal in the receiver coil CW Oscillator GATE DC Pulse generator Probe In Magnet RF Pulse Receiver- detector Display Monitor Recorder Z X Y

OUTPUT from the FFT Program: Time domain FID and the Frequency domain two line NMR spectrum Real imaginary

Field = H H/2 H/4 H/6.6 Spectrometer operating frequency decreases Distance of separation between the multiplets varies with the field Separation within the multiplets remain unchanged with the field