Figure 4.

Effect of coil loading on the receiver recovery time. a. ³¹P magnitude spectrum of a vial of 85% phosphoric acid, which loads the coil severely, shortens the coil ring-down and reduces the Q to 37. The software receiver dead time delay was set to 10 μs. b. ³¹P magnitude spectrum of a vial of hydroxyapatite, which does not load the coil and maintains the Q at 115. With the software receiver dead time delay set to 10 μs the coil ring-down creates a strong artifact in the spectrum. c. Same as b, except that the receiver dead time delay is increased to 20 μs, which blocks the coil ring-down signal and permits acquisition of a distortion-free spectrum.