Problem 6.273

The irradiation of lithium and beryllium targets by a monoergic stream of protons reveals that the reaction \(\mathrm{Li}^{7}(p, n) \mathrm{Be}^{7}\) \(-1.65 \mathrm{MeV}\) is initiated whereas the reaction \(\mathrm{Be}^{9}(p, n) \mathrm{B}^{9}-1.85 \mathrm{MeV}\) does not take place. Find the possible values of kinetic energy of the protons.