This directory contains an updated ESS source component for use with McStas 2.x and 1.12c - dated February 2015!

The component comes with a library of ESS source brilliances, including:

IMPORTANT: This component DOES NOT implement the "optimized thermal" or "butterfly" like moderators - a new version will be released in connection with McStas 2.2 spring 2015.

An important detail about the 2014-pancake moderator is that the component origin is NOT at the centre of the cylindrical cold source, but instead at the middle of the front face of the cylinder. For technical reasons, neutrons are in this case propagated from a tangential plane at this point.

The difference with respect to the July 2014 version released with McStas 2.1 and as a tarball to is a bug reported by Jan Saroun regarding to solid angle correction in the 2014 / pancake case.

Please also read the "usage recommendations" provided in the enclosed PDF

Peter Willendrup