Reply To: Newbie pB11 Fuel Questions

[JimmyT]

NoSmoke wrote:

If p-B11 does work, and works well, would p-N14 also be a good possibility (not sure if there would be any great incentive to go there though).

If the neutrons produced by p-B11 side reactions are not energetic enough to induce radioactivity, what happens to them (do they decay or just hang around)?

There is a good reason to prefer boron (atomic number 5) to nitrogen(atomic number 7) as a fuel. It’s the problem of minimizing x-ray emissions. X-ray emission increases with the square of the atomic number … so boron has 25 times the x-ray emissions of hydrogen. Nitrogen would have 49 times the emissions of hydrogen. Almost twice as much.

Note: All this talk of x-rays can get confusing. These x-rays are not the reaction x-rays which we talk of harvesting for energy. (although some of them might be recaptured in this way) These are x-rays given of throughout the compression phase and reaction phase, and which tend to cool the reactants. They also tend to be somewhat softer (longer wavelength, less energy) than the reaction x-rays.