Exercise: Insert a real sample

1. Instead of mylist.dat use Na2Ca3Al2F14.laz. Change the limits of the banana detector to [-10 -130] and change the sample component to read:

   COMPONENT sample = PowderN(
       reflections = "Na2Ca3Al2F14.laz", d_phi = 0.1, radius = 0.004,
       h = 0.03, DW = 0.9, barns = 1, pack = 0.7, frac = 0, tfrac=0)
     AT (0, 0, 2) RELATIVE arm2
   

   Make a simulation to check that a nice powder pattern is observed. If it is time for a coffee break, close the plot from the quick run and instead do a long simulation, e.g. 20 million neutron rays, and have coffee.