Paper , Order, or Assignment Requirements

Assignment 1 :

1. Using an Excel spreadsheet or similar software, construct and show plots of the amplitude and frequency wave forms for the radio-frequency pulses given below using the parameters as given for each pulse :

(i) a Gaussian pulse of duration Tp = 5.0ms, peak amplitude RFmax = 100.0 and number of points np = 256.                                      (3 marks)

(ii) a half passage sech/tanh adiabatic pulse with duration Tp = 10.0ms, peak amplitude RFmax = 100.0, bwdth = 10 kHz and number of

points np = 256.                                                       (3 marks)

(iii) a full passage sech/tanh adiabatic pulse with duration Tp = 10.0ms, peak amplitude RFmax = 100.0, bwdth = 10 kHz and number of

points np = 256.                                                       (4 marks)

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2. For each of the pulses above, using vector diagrams in the rotating frame of reference sketch the trajectory of the magnetization vector at the end of the pulse assuming full excitation (i.e. 90 degrees) for pulses in (i) and (ii) and full 180 degree rotation for the pulse in (iii) (6 marks)