Main question: Is it possible to achieve net power generation based on linear proton accelerator and U-238 target?
In the proposed reactor design there is a proton beam with energy ~10 GeV, and on U-238 target where these protons should generate cascade neutron generation & U-238 fission with high-energy neutrons.
The problem though is that there is some disagreement on energy looses and neutron multiplicity.
My estimations and understanding is the following:
- 60% of incident proton energy goes into heat.
- For high energy protons (>1GeV) there are significant loses on pi-0 decay, so using proton energy above 1-1.5GeV is inefficient. Is there other significant ways of loosing energy?
- Estimated number of neutrons generated is 120-250 per incoming 10 GeV proton on Uranium target.
- Only fraction of such neutrons have energy high enough to support fission of U-238
- If only 25% of these neutrons would cause 1 fission, we'll only have ~180/4*0.2=9 GeV of fission + comparable amount of energy in neutrons and high-energy gamma (from pi-0 decay)
Does that seems to be correct? Is there any papers investigating possibility of spallation-based net power generation on U-238/Thorium reactors? (i.e. without classical fissile materials like U-235, U-233 or Plutonium)
Also, based on published specs of SINQ-2 spallation neutron generator, I calculated it's neutron generation efficiency to be 0,024% of proton beam power. Even if we replace spallation target with Uranium one, it's efficiency would be 0,1662% at best. Obviously, with such efficiency we cannot support net power generation. Does that mean that this idea is not workable?