In a fusion reactor, the reaction occurs in two stages.
(i) Two deuterium `(""_(1)^(2)D)` nuclei fuse to form a tritium `(""_(1)^(3)T)` nucleus with a proton as product.
(ii) A tritium nucleus fuses with another deuterium nucleus to form a helium `(""_(2)^(4)He)` nucleus with neutron as another product.
Find (a) the energy released in each stage. (b) the energy released in the combined reaction per deuterium and (c) what percentage of the mass energy of the initial deuterium is released?
Given : `""_(1)^(2)D=2.014102u,""_(1)^(3)T=3.016049u,""_(2)^(4)He=4.002603u,""_(1)^(1)H=1.007825u,""_(0)^(1)n=1.008665u` Take 1u = 931 MeV

Explanation

(a) `""_(1)^(2)D+""_(1)^(2)Dto""_(1)^(3)T+""_(1)^(1)H+Q_(1)`
`thereforeQ_(1)=0.00433xx931MeV`
= 4.031 MeV.
`""_(1)^(3)T+""_(1)^(2)Dto""_(2)^(4)He+""_(0)^(1)n+Q_(2)`
`thereforeQ_(2)=0.01888xx931MeV`
= 17.577MeV.
(b) Energy released per deuterium nucleus
= `2161/3=7.203`MeV
( c) Percentage of rest mass of deuterium released
`(7.203MeV)/((2.014102xx931)MeV)=0.384%`