# How much energy does proton - carbon 12 fusion produce?

Page 25 of this document from the California Institute of Technology says that proton-carbon 12 fusion releases 7.54 MeV, while Wikipedia says it releases 1.95 MeV. Which one is correct?

• Looks like a copy-n-paste error in the PDF. Note that the energy is the same as for the C-13 to N-14 line. – dmckee Mar 6 '16 at 17:29
• OK, so what does a third (and fourth) source say? It's not all that hard to figure out who's in error. – Carl Witthoft Mar 6 '16 at 19:28

OK, you are referring to the fusion reaction

$^{12}$C + $^{1}$H $\rightarrow$ $^{13}$N + $\gamma$.

Let's neglect the $\gamma$ and insert the atomic masses

$12\cdot u + 1.00782503223\cdot u = 13.005738609\cdot u + x$,

where $x$ is an upper boundary for the released energy (since we neglected the $\gamma$). The data for the atomic masses is from the NIST website and from wikipedia.

Solving that equation yields

$x=0.00208642323\cdot u$

which corresponds to ($1\cdot u$ corresponds approximately to $931.5$ MeV)

$x\approx 1.94$ MeV.

Therefore, the wikipedia value seems to be right.