1. Resonance condition

2. Pulse A coil of wire placed around the X axis will provide a magnetic field along the X axis when a direct current is passed through the coil. An alternating current will produce a magnetic field which alternates in direction. In magnetic resonance, the magnetic field created by the coil passing an alternating current at the Larmor frequency is called the B 1 magnetic field. When the alternating current through the coil is turned on and off, it creates a pulsed B 1 magnetic field along the X' axis. http://www.cis.rit.edu/htbooks/nmr/inside.htm

3. The spins respond to this pulse in such a way as to cause the net magnetization vector to rotate about the direction of the applied B 1 field. The rotation angle depends on the length of time the field is on,, and its magnitude B 1.  = 2  B 1. In our examples, will be assumed to be much smaller than T 1 and T 2. http://www.chem.queensu.ca/FACILITIES/NMR/nmr/webcourse/index.htm

4. Pulse Application for a specified period of time of a radio-frequency pertubation which excites the spin system non-selectively over a given bandwidth  time period; bandwidth=1/  Flip-angle of a pulse:  =  B 1 B 1 :strength of r.f. field For proton 90  pulse is about 10 W and  ~  s 

5. Flip Angle of the pulse http://www.chem.queensu.ca/FACILITIES/NMR/nmr/webcourse/index.htm  

6. Perturbation by RF Pulse

7. Pulse Sequence

8. The Pulse FT NMR Experiment equilibration 90º pulse detection of signals Experiment (t) Data Analysis Fourier Transform Time domain (t)