McStas installation and questions

[Kristian Nielsen]

> I'm now designing IN14 instrument description for McStas. Are there
> some new source files (shape, or energy distribution not flat, for
> instance Maxwelian,...) or other components in general ? Future
> versions of McStas should also handle neutron spin (state and
> direction).

Currently, we have only circular sources with flat energy distributions,
since we have not needed anything else yet. You can get a rectangular
source by putting a slit just in front of a circular one. If you want,
you could try to modify the Source_flat component yourself as an
exercise in writing McStas components, i.e. to use a rectangular shape
and multiply the weight by a Maxwelian. Or if you prefer, I could do it
for you (it would only involve adding a few lines).

I talked to Arnaud Hiess. He gave me a quick overview of ResTraxx and of
the departments at the ILL, both of which were very helpful. We then
went through the instrument definition for TAS1 and created a drawing
with all the relevant dimensions and parameters. Of course, if we missed
anything, just ask again.

Good luck,

 - Kristian.