An accurate way to measure the spin-lattice relaxation time (T1) using pulsed NMR is to rst apply a 1800 pulse, then a 900 pulse after a delay time T. The amplitude of the response immediately following the 900 pulse is a maximum when T=O, because the net 1800 + 900 = 2700 pulse rotates all spins into the x-y plane (similar to a single 900 pulse). However, for T>D this amplitude decreases as spins relax from 1800 back to zero Via spin-lattice relaxation. The minimum amplitude occurs for Tmm, when the majority of spins have rotated 900 back towards zero, so that the 900 pulse yields the smallest signal. Note that this Tmin is the time for the spins to rotate halfway back to zero (similar to a half-life in radioactive decay), whereas the spin-lattice relaxation time T1 is dened by the exponential relaxation M=M0 exp(t/ T1}. C? Question 1 2 pts Suppose that you find that the minimum amplitude occurs at Tmin = 18.84 ms.The resulting spin-lattice relaxation time is: T1 = ms. 62.5 The table (pasted below) gives the delay-time dependence of the signal amplitude immediately following the 900 pulse. Fit the data to a quadratic function to determine the time where the amplitude is a minimum, Tmin, then convert to the corresponding exponential relaxation time. This spin-lattice relaxation time is: T1 = ms. t(ms) A(mV) 19.7 32.5 19.6 28.2 19.4 21.8 19.2 17.5 19 15.3 18.8 15.2 18.6 16.8 18.4 21.5 18.2 28.1 18 36.9