The gyromagnetic ratio of 31P is 1.08 x 108 rad s-1 T-1. This nucleus shows a wide range of shifts, covering some 700 ppm.
Suppose that the transmitter is placed in the middle of the shift range and that a 90° pulse of width 20 μs is used to excite the spectrum; the spectrometer has a B0 field strength of 9.4 T. Estimate the size of the phase correction (in radians and in degrees) which will be needed at the edges of the spectrum.