In many MR experiments it is necessary to flip a spin, which is initially along the z-axis, into the x'y' plane by using an appropriate rf pulse. This is referred to as a '90° or 'n/2' pulse. If the desired rf pulse time interval is 1.0ms, what B₁ magnitude in µT (1T = 10,000G) is required for a. a proton spin? b. an electron spin? C. How many Larmor precession cycles take place in the laboratory frame, for B0= 1.0 T, during the 1/2 flip of the proton spin?

In many MR experiments it is necessary to flip a spin, which is initially along the z-axis, into the x'y' plane by using an appropriate rf pulse. This is referred to as a '90° or 'n/2' pulse. If the desired rf pulse time interval is 1.0ms, what B₁ magnitude in µT (1T = 10,000G) is required for a. a proton spin? b. an electron spin? C. How many Larmor precession cycles take place in the laboratory frame, for B0= 1.0 T, during the 1/2 flip of the proton spin?