▁a ▁pressure ▁of ▁ 5 0   bar ▁and ▁a ▁temperature ▁of ▁ 4 3 0   ° C . ▁ ▁History ▁▁ ▁The ▁first ▁THE M IS ▁solar ▁plant , ▁was ▁an ▁experimental ▁solar ▁facility ▁which ▁produced ▁power ▁between ▁ 1 9 8 3 ▁and ▁ 1 9 8 6 , ▁and ▁then ▁closed ▁in ▁part ▁due ▁to ▁the ▁difficulty ▁of ▁man aging ▁the ▁cool ing ▁system , ▁and ▁in ▁part ▁due ▁to ▁a ▁lack ▁of ▁political ▁and ▁financial ▁support . ▁Const ruction ▁started ▁in ▁ 1 9 7 9 ▁at ▁a ▁cost ▁of ▁ 3 0 0 ▁million ▁French ▁fran cs ▁( about ▁ 4 5 ▁million ▁eu ros ), ▁and ▁was ▁operated ▁and ▁managed ▁by ▁É lect ric ité ▁de ▁France ▁( ED F ). ▁ ▁The ▁plant ▁went ▁into ▁hi bern ation ▁for ▁more ▁than ▁twenty ▁years , ▁and ▁turned ▁into ▁a ▁scientific ▁facility ▁of ▁the ▁C ER N , ▁and ▁the ▁Comm iss ariat ▁à ▁l ' é ner gie ▁atom ique ▁foc using ▁on ▁ast ro physics , ▁with ▁an ▁open ▁air ▁Ch eren kov ▁T eles cope , ▁meas uring ▁g amma ▁ray s ▁hitting ▁the ▁atmosphere ▁( see ▁I ACT ). ▁ ▁In ▁ 2 0 0 4 , ▁a ▁re h abil itation ▁program ▁was ▁de vised ▁by ▁the ▁General ▁Council ▁of ▁the ▁P yr én ées - Ori ent ales , ▁to ▁produce ▁power , ▁and ▁create ▁a ▁ ▁research ▁and ▁development ▁centre ▁on ▁solar ▁energy ▁with ▁the ▁Centre ▁national ▁de ▁la ▁recherche