Nuclear Magnetic Resonance ANIMATED ILLUSTRATIONS MS Powerpoint Presentation Files Uses Animation Schemes as available in MS XP or MS 2003 versions A class room educational material File-4 Principles of NMR signal detection: NMR Spectrum http://ugc-inno-nehu.com/links_from_web.html

CLICK to transit to next slide Oscillation Level reduced when there is ESR absorption Oscillation Level at fixed frequency ‘ν’ When No ESR Detected DC Level No ESR 2 Oscillator Oscillation Level Detector 1 Φ Shifter Reduced DC On ESR Absorption hν=gβH Detected Oscln Level DC No oscillations 0 The role of a phase Φ shifter in the diagram would be explained in the succeeding slides If the Current is increased from 0 to beyond resonance field, then, the field [ Ht ] increases with time and causes resonance at resonance field value Ht hν=gβH 2 Current Source 1 CLICK to transit to next slide

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

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

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