This is the future of fusion, not D-T fusion. Or use Lithium instead of Boron.

Lithium is even better than Boron because you don't need isotope separation (since both work), and you get more power out of it.

The Boron or Lithium doesn't need to be a plasma, and you don't need to confine it. This makes it much simpler to handle.

You leave it as a solid and just hit it with protons. Not all the protons will do anything. If you can recycle the energy of the failed protons then the low efficiency can be mitigated.

Those that hit will leave behind helium (both H3 and H4) you probably need to remove that to prevent interfering with incoming protons. But there is no other ash to worry about. (And the H3 is very useful - you can even use it for energy.)