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Fusion in the sun II.
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•“Unfortunately” 2He isn’t stable
–To get stable He need to add one or two neutrons to:
•Increase Strong Force, without increasing Coulomb force
–Not really “unfortunate” – If 2He were stable:
•Sun would burn energy way too fast – and would have gone out by now
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•Weak force converts proton to neutron–fusion will be slow
–In solar fusion no excess neutrons lying around
–Hydrogen bombs use deuterium: 2H = (p+ n) or tritium:  3H = (p+ n n) to provide it