An alpha particle with kinetic energy, $T=5.3 \mathrm{MeV}$ initiates a nuclear reaction, ${\mathrm{Be}}^9(\alpha , n){\mathrm{C}}^{12}$ with energy yield, $Q=+5.7 \mathrm{MeV}$. Find the kinetic energy of the neutron outgoing at right angles to the motion direction of the alpha-particle.

Excess of the mass of atoms $∆{\mathrm{Li}}^7=0.01601 \mathrm{amu}, ∆{\mathrm{He}}^4=0.00260 \mathrm{amu}$ and $∆\mathrm{H}=0.00783 \mathrm{amu}$ and of neutron and proton are$∆{\mathrm{m}}_{\mathrm{p}}=0.00783 \mathrm{amu}$ 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.

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.