Based on neutron component written by Kim Lefmann
An (nx times ny) pixel PSD monitor. This component may also be used as a beam
detector. If instead of xwidth, yheight a radius is given, the component has a circular footprint
and integrates circularly (caking).
Example: PSD_monitor(xmin=-0.1, xmax=0.1, ymin=-0.1, ymax=0.1,
nx=90, ny=90, filename="Output.psd")
Parameters in boldface are required;
the others are optional.
Number of pixel columns
Number of pixel rows
Number of radial pixels
Name of file in which to store the detector image
If set, the monitor does not influence the xray state