Gas Producing Reactions

Nuclear reactions can result in a number of different products, including photons, neutrons, light charged particles, and heavy residual nuclei. The identities of the products are sometimes implicit in the MT number for the reaction, and they are sometimes given explicitly in the section of File 6 corresponding to the reaction. When the products are implicit, they are produced with integer yields. The following table gives some common examples:

221 neutron, 1 alpha, residual
1031 proton, residual
1112 protons, residual
1131 triton, 2 alphas, residual

Of course, the residual could also be a light charged particle, and it may contribute to the gas production cross section.

Many of the newer evaluations now available use File 6 to provide a complete accounting of all the particles produced in a nuclear reaction, including their yields and their distributions in angle and energy. If the section in File 6 uses a simple MT number, like those tabulated above, the explicit yields will be the same as the implicit ones. However, it is also possible to use MT=5 with File 6. This MT is the sum over a number of reaction channels, and the particle yields do not have to be integers. GASPR is able to take account of these non-integer particle yields and add the correct contributions to the total gas production.


23 January 2013 T-2 Nuclear Information Service