[mesa-users] networks

[David Arnett]

Networks are about abundant species AND reaction links. If rates are fast
they destroy things in the entrance channels, so that these species may
become LOW in abundance. This is the Catch 22. Both aspects must be
accurately represented. Neutrons and protons, with the nonexistent and the
low coulomb barrier, are low in abundance but strong links.

I agree with Bill. Look at the larger (not hard-wired) net and examine the
links. I always found that greatly clarifying. Rule of thumb: you need n~25
for energetics and gross abundances for H and He burning, 50 for C to O
burning, and 100 to 150 for Si burning and neutronization. The devil is in
the details, so this is only a rough guide. Even 150 species fit nicely in
a core ;-)

-- 
David Arnett
Regents Professor
Steward Observatory
University of Arizona

Facts are stubborn, but statistics are more pliable.  Mark Twain
Facts do not cease to exist because they are ignored.  Aldous Huxley
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