Glenn, a few thoughts (#4 is the most important):
1. Is it necessary to have the plus sign between ‘H’ and ‘B’? Since the diagram arrows imply they are combining, the plus sign is redundant.
2. Should there be a depiction of the temporary ‘C’ atom formed where ‘H’ and ‘B’ combine?
3. The ‘He’lium symbol shouldn’t be in the center of the reaction; there should be three arrows going away from the center with three ‘He’lium labels on the output nuclei, just like the two nuclei going into the reaction.
4. Where’s the energy release depicted?! The whole point is that this is a huge source of energy. It needs to be listed along with the ‘He’lium output, but with much more emphasis; bigger font, bold… something. Actually, I’d place it at the center as some “explosive” icon with a “+ 8.7 MeV” label. The ‘He’lium output lines that I suggested in point 3 should then come away from that explosion.
5. With the current top-to-bottom layout, it will be cramped if you add any of these details. Changing the reaction to proceed left-to-right would give you room to expand, and keep the very top and bottom text where it is.
I didn’t intend to be critical of the current design, but I do think my ideas would provide clarity and potency to the idea depicted.
P.S. I really like the stylized plasma focus you created here for the background.