Let's collect links to useful other sites here. I recently got this one to neutron capture->gamma energy data:
http://www.nndc.bnl.gov/capgam/indexbyn.html
The above would be more useful in the specific case I'm interested in if I had a link to capture cross sections too.
The site sells "the" book for $353, a bit rich for me. I'm building a directional neutron camera, and it was a bit of surprise to find out that H has a 2.2 MeV gamma on neutron capture!
However, I know it's low cross section from other sources, but not for example, enough to know whether carbon would do better for the moderator I want to use to exclude fast
neutrons from the directions the fast N sensor isn't pointed in. Most n captures result in a gamma that you then have to shield -- but if capture cross section is low enough, it won't reduce
the camera contrast too badly -- the fast N sensor (plastic scint/phototube) also sees gammas, and these hot ones need too much lead to stop.
The full site is:
http://www.nndc.bnl.gov/content/siteindex.html