9 8 0 , ▁and ▁produced ▁a ▁concept ual ▁design ▁by ▁mid - 1 9 8 1 . ▁ ▁In ▁ 1 9 8 5 , ▁at ▁the ▁Gene va ▁sum mit ▁meeting ▁in ▁ 1 9 8 5 , ▁Mik h ail ▁G orb ache v ▁suggested ▁to ▁Ron ald ▁Re agan ▁that ▁the ▁two ▁countries ▁joint ly ▁undert ake ▁the ▁construction ▁of ▁a ▁to k am ak ▁E PR ▁as ▁proposed ▁by ▁the ▁INT OR ▁Work shop . ▁The ▁I TER ▁project ▁was ▁initi ated ▁in ▁ 1 9 8 8 . ▁ ▁Re actor ▁over view ▁ ▁When ▁de uter ium ▁and ▁tr it ium ▁f use , ▁two ▁nuc lei ▁come ▁together ▁to ▁form ▁a ▁hel ium ▁nucle us ▁( an ▁alpha ▁particle ), ▁and ▁a ▁high - energy ▁neut ron . ▁ ▁+ ▁ ▁→ ▁ ▁+ ▁ ▁+ ▁ ▁While ▁nearly ▁all ▁stable ▁is ot op es ▁l ighter ▁on ▁the ▁periodic ▁table ▁than ▁iron - 5 6 ▁and ▁nick el - 6 2 , ▁which ▁have ▁the ▁highest ▁binding ▁energy ▁per ▁nucle on , ▁will ▁f use ▁with ▁some ▁other ▁is ot ope ▁and ▁release ▁energy , ▁de uter ium ▁and ▁tr it ium ▁are ▁by ▁far ▁the ▁most ▁attract ive ▁for ▁energy ▁generation ▁as ▁they ▁require ▁the ▁lowest ▁activation ▁energy ▁( th us ▁lowest ▁temperature ) ▁to ▁do ▁so , ▁while ▁producing ▁among ▁the ▁most ▁energy ▁per ▁unit ▁weight . ▁ ▁All ▁proto - ▁and ▁mid - life ▁stars ▁radi ate ▁enorm ous ▁amounts ▁of