Reply To: Military Effects

[asymmetric_implosion]

Dennisp: I don’t agree with you analogy. Carbon-12 has many possible exit channels to release its energy such as re-emitting the proton, emitting a gamma or falling apart. The brick does not have the same option. There are reasons the carbon-12 is not stable and energy plays a role as I said above. The ability to conserve momentum is the reason. Energy and momentum are linked quantities. If you look at the fission of U-235 by neutrons it produces the largely stable U-236 after absorbing the neutron. The time of stability is 12C->4He+8Be; 8Be->2*4He. p+11B is a bit unique in that it takes advantage of the stability of He-4 for it’s location on the periodic table. He-4 has a binding energy per nucleon of 7 MeV/nucleon. Fe-56 has binding energy per nucleon of 8.7 MeV/nucleon (near top of the charts). 11B is 6.9 MeV/nucleon. The general trend is binding energy per nucleon increases with Z until you reach Fe. After Fe, binding energy per nucleon decreases leading to less stable nuclei. p+11B moves toward stability by reducing product atomic number rather than increasing it. Why work harder when you can work smarter? Why gain atomic number per product when losing atomic number per product is more favorable?

Look at the reactions below. Which ones are the most alike?

D+T->5He->4He+n
D+D->4He->p+T
n+235U->236U->Xn+products (Too many to list, X~2.3)
p+11B->12C->4He+8Be->3*4He