▁consisting ▁of ▁two ▁Fine - G rained ▁sc int ill ation ▁Det ectors ▁( F G D s ) ▁and ▁three ▁Time ▁Pro jection ▁Ch amb ers ▁( TP C s ), ▁will ▁maintain ▁their ▁sand wich ed ▁structure ▁and ▁continue ▁to ▁detect ▁forward ▁going ▁le pt ons ▁and ▁high ▁momentum ▁hard ons . ▁The ▁up stream ▁part ▁which ▁now ▁hosts ▁the ▁P 0 D ▁sub - det ector ▁will ▁be ▁replaced ▁by ▁three ▁novel ▁sub - det ectors : ▁a ▁sc int ill ating ▁ 3 D ▁target ▁( Super ▁Fine - G rained ▁Det ector ▁or ▁Super F G D ), ▁two ▁new ▁T PC s ▁on ▁top ▁and ▁below ▁the ▁Super F G D ▁( High - Angle ▁T PC s ▁or ▁H AT PC s ), ▁and ▁six ▁Time - of - F light ▁( TO F ) ▁detect ors ▁surrounding ▁the ▁new ▁structure . ▁Each ▁of ▁these ▁sub - det ectors ▁is ▁briefly ▁described ▁below . ▁ ▁Super F G D ▁ ▁The ▁Super F G D ▁is ▁a ▁ 2 m ▁x ▁ 2 m ▁x ▁ 0 . 5 m ▁det ector ▁consisting ▁of ▁approximately ▁ 2 ▁million ▁ 1   cm 3 ▁sc int ill ating ▁pol yst y rene ▁cub es . ▁The ▁cub es ▁are ▁w oven ▁with ▁a ▁series ▁of ▁optical ▁fib res ▁designed ▁to ▁detect ▁the ▁light ▁em itted ▁by ▁the ▁particles ▁produced ▁during ▁the ▁interactions ▁in ▁the ▁target . ▁Un like ▁the ▁current ▁F G D s , ▁the ▁Super