Start by inserting a template instrument (Insert menu). Set up an instrument, consisting only of an Arm (keep the example 'a1' Arm instance), a Source_Maxwell_3,
a PSD_monitor and an L_monitor. Read the documentation for each of
the components to find the needed input parameters. For the source we
will help you out, try
COMPONENT source = Source_Maxwell_3(
size = 0.1, l_low = 0.1, l_high = 10, dist = 10, xw = 0.01,
yh = 0.01, T1 = 300, T2=300, T3=300, I1=1e14, I2=0, I3=0)
Read the Source_Maxwell_3 docs using mcdoc to understand the
suggested parameters. The file names for monitors, specified as character strings, should be given surrounded by double quotes ("file.dat").