Fitting Pulsed NMR Data for Spin-Lattice Relaxation Time (T1)

[PhysicsGente]

Hello, I didn't know where else to post this so here it goes ...

I have collected data from a pulsed NMR experiment to calculate the value of the spin-lattice relaxation time (T1). Now I'm asked to fit the data using a function of the form
V(t) = V_0*(1 - 2*exp(-t/T1)). But I'm not really sure how to fit it. Is there any software out there I can use to fit this data with that function? I was trying to fit it using ROOT but I did not succeed ;(.

The data is here, https://docs.google.com/open?id=0BwZLQ_me50B8VExfYU1GX2dyV3M

 

[mfb]

ROOT can fit that, but you should restrict the fitting range to t>=50 or use a different fit function ($|V(t)|$ looks like a good idea), otherwise the result is meaningless. Even there, I doubt that the function gives a good approximation to the measured values.