▁energy ▁generated ▁by ▁fusion ▁processes . ▁Mass ▁for ▁mass , ▁the ▁de uter ium – tr it ium ▁fusion ▁process ▁releases ▁roughly ▁three ▁times ▁as ▁much ▁energy ▁as ▁u ran ium - 2 3 5 ▁f ission , ▁and ▁millions ▁of ▁times ▁more ▁energy ▁than ▁a ▁chemical ▁reaction ▁such ▁as ▁the ▁burning ▁of ▁coal . ▁It ▁is ▁the ▁goal ▁of ▁a ▁fusion ▁power ▁station ▁to ▁har ness ▁this ▁energy ▁to ▁produce ▁electric ity . ▁ ▁Activ ation ▁energ ies ▁for ▁fusion ▁re actions ▁are ▁generally ▁high ▁because ▁the ▁pro tons ▁in ▁each ▁nucle us ▁will ▁tend ▁to ▁strongly ▁rep el ▁one ▁another , ▁as ▁they ▁each ▁have ▁the ▁same ▁positive ▁charge . ▁A ▁he ur istic ▁for ▁estim ating ▁reaction ▁rates ▁is ▁that ▁nuc lei ▁must ▁be ▁able ▁to ▁get ▁within ▁ 1 0 0 ▁fem tom eters ▁( 1 ▁× ▁ 1 0 − 1 3 ▁meter ) ▁of ▁each ▁other , ▁where ▁the ▁nuc lei ▁are ▁increasing ly ▁likely ▁to ▁under go ▁quantum ▁t unn eling ▁past ▁the ▁electro static ▁bar rier ▁and ▁the ▁turning ▁point ▁where ▁the ▁strong ▁nuclear ▁force ▁and ▁the ▁electro static ▁force ▁are ▁equally ▁bal anced , ▁allowing ▁them ▁to ▁f use . ▁In ▁I TER , ▁this ▁distance ▁of ▁approach ▁is ▁made ▁possible ▁by ▁high ▁temper atures ▁and ▁magnetic ▁conf in ement . ▁High ▁temper atures ▁give ▁the ▁nuc lei ▁enough ▁energy ▁to ▁overcome ▁their ▁electro static ▁rep ulsion ▁( see ▁Max well – B olt z mann ▁distribution ). ▁For ▁de uter ium ▁and ▁tr