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McStasMcXtrace / McCode

The home of the McStas (neutrons) and McXtrace (x-rays) Monte-Carlo ray-tracing instrument simulation codes.
https://github.com/McStasMcXtrace/McCode/wiki
GNU General Public License v3.0
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Incorrect material data for H2O #1585

Open anicecloud opened 5 months ago

anicecloud commented 5 months ago

Good afternoon, when experimenting with the tool we noticed that the data labeled as H2O (mcxtrace-comps/data/H2O.txt) seems to actually be a duplicate of the h2o2 (mcxtrace-comps/data/h2o2.dat).

willend commented 5 months ago

@anicecloud thank you, I have just inspected the data dir - I confirm this is the case, and that is of course not right!

I noticed on the other hand there are two 2-column files called H2O_hot.txt and H2O_cold.txt (without any evident definition of hot / cold, but I am guessing ambient temperature and ~ boiling perhaps?) - try if they make better sense?

@farhi or @ebknudsen could you remind a poor neutron-guy the origin of these .txt files? :-) And perhaps help enriching with some header-information etc.? ;-)

ebknudsen commented 5 months ago

H2O_hot.txt and H2O_cold.txt hail from a Pump-probe experiment so it is ambient, and somewhat hotter than that. Off the top of my head I can't remember exactly how hot hot is. I think I can figure it out though by digging a bit. Of course the H2O/H2O2-confusion is a mistake. They should not be identical.

willend commented 5 months ago

So @ebknudsen I take it copying H2O_cold.txt over H2O.txt and adding a header to both indicating "water at ambient temperature" would be a reasonable correction?

ebknudsen commented 5 months ago

Nope - they are two different things in the sense that H2O_cold contains scattering in terms of p as a function of q, whereas H2O.txt was intended to table absorption coefficient as a function of E. This is obviously not clear from the numbers in the files. There should be some header to the two files. Someone (as in @ebknudsen, i.e. me) should add that info.