Two fusion reactions of interest for controlled energy generation are listed below

PHYSICS · Multi-part · A Level · Physics · Nuclear physics · Nuclear physics

Problem

Two fusion reactions of interest for controlled energy generation are listed below. Reaction A (D–T):

^{2}\text{H}+{}^{3}\text{H}\rightarrow{}^{4}\text{He}+n

Reaction B (p–p):

p+p\rightarrow d+e^{+}+\nu_{e}

(neutrino energy ignored) Atomic masses (in

u

^{2}\text{H}=2.014102

^{3}\text{H}=3.016049

^{4}\text{He}=4.002603

n=1.008665

p=1.007825

d=2.014102

e^{+}=0.000549

. Constants:

1\,u\,c^{2}=931.5\,\text{MeV}

1\,\text{MeV}=1.602\times10^{-13}\,\text{J}

N_A=6.022\times10^{23}\,\text{mol}^{-1}

. (i) For each reaction, calculate the energy released per fusion event, in MeV. (ii) Determine the energy released per nucleon for each reaction. Which reaction is more efficient on this basis? (iii) A pilot D–T fusion plant consumes

5.0\,\text{g}

of deuterium each second, with equal numbers of tritium nuclei available. Estimate the electrical power output in megawatt (MW) if the plant converts

40\%

of the liberated nuclear energy into electrical energy.

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