Question

Calculate the threshold kinetic energies of protons required to activate the reactions `(p,n)` and `(p,d)` with `Li^(7)` nuclei.

Answer 1

The `Q` of the reaction `Li^(7)(p,n)Be^(7)` was calculated in problem 266(a). It is `-1.64MeV` Hence, the threshold `K.E`. Of proton for initiating this reaction is
`T_(th)=(1+(m_(p))/(m_(Li)))|Q|=(8)/(7)xx1.64= 1.64= 1.87MeV`
For the reaction `Li^(7)(p,d)Li^(6)`
we find `Q=(Delta_(Li)^(7)+Delta_(M)-Delta_(d)-Delta_(Li)^(6))c^(2)`
`=(0.01601+0.00783-0.01410-0.01513)am uxxc^(2)`
`=-5.02MeV`
The threshold proton energy for initiating this reaction is
`T_(th)=(1-(m_(p))/(m_(Li^(7))))xx|Q|=5.73MeV`