3) Assuming we are using a spin-echo pulse sequence, if a 90 pulse is applied at t=0ms, a 180 pulse is applied at t=10 ms, and a second 180 pulse is applied at 25 ms, at what times will we receive a signal in the RF coil. Sketch an intensity (arbitrary units) vs. time plot and be sure to indicate what the signal received on an RF coil will look like. Label the T2* and T2 Relaxation curves.