To activate the reaction $(n, \mathrm{\alpha })$ with stationary ${\mathrm{B}}^{11}$ nuclei, neutrons must have the threshold kinetic energy, $T_{\mathrm{th}}=4.0 \mathrm{MeV}$. Find the energy of this reaction.

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

Excess of the mass of atoms $∆{\mathrm{Li}}^7=0.01601 \mathrm{amu}, ∆{\mathrm{Be}}^7=0.01693 \mathrm{amu}$ and of neutron and proton are$∆{\mathrm{m}}_{\mathrm{p}}=0.00783 \mathrm{amu} \mathrm{and} ∆{\mathrm{m}}_{\mathrm{n}}=0.00867 \mathrm{amu}$

$1 \mathrm{amu}=1.67\times {10}^{-24} \mathrm{g}$ and $1 \mathrm{amu}$ is equivalent to $931.5 \mathrm{MeV}$ of energy.

Excess of the mass of atoms $∆{\mathrm{Li}}^7=0.01601 \mathrm{amu}, ∆{\mathrm{Be}}^{10}=0.01294 \mathrm{amu}$ and of neutron and $\alpha -$particles are$∆{\mathrm{m}}_{\mathrm{\alpha }}=0.00260 \mathrm{amu} \mathrm{and} ∆{\mathrm{m}}_{\mathrm{n}}=0.00867 \mathrm{amu}$

$1 \mathrm{amu}=1.67\times {10}^{-24} \mathrm{g}$ and $1 \mathrm{amu}$ is equivalent to $931.5 \mathrm{MeV}$ of energy.

Excess of the mass of atoms $∆{\mathrm{He}}^3=0.01603 \mathrm{amu}, ∆\mathrm{d}=0.01410 \mathrm{amu}$ and of neutron and proton are$∆{\mathrm{m}}_{\mathrm{p}}=0.00783 \mathrm{amu} \mathrm{and} ∆{\mathrm{m}}_{\mathrm{n}}=0.00867 \mathrm{amu}$

$1 \mathrm{amu}=1.67\times {10}^{-24} \mathrm{g}$ and $1 \mathrm{amu}$ is equivalent to $931.5 \mathrm{MeV}$ of energy.

Excess of the mass of atoms $∆{\mathrm{C}}^{13}=0.00335 \mathrm{amu}, ∆{\mathrm{N}}^{15}=0.00011 \mathrm{amu} \text{and} ∆\mathrm{d}=0.01410 \mathrm{amu}$ and of neutron and proton are$∆{\mathrm{m}}_{\mathrm{p}}=0.00783 \mathrm{amu} \text{and} ∆{\mathrm{m}}_{\mathrm{n}}=0.00867 \mathrm{amu}$

$1 \mathrm{amu}=1.67\times {10}^{-24} \mathrm{g}$ and $1 \mathrm{amu}$ is equivalent to $931.5 \mathrm{MeV}$ of energy.