, ▁may ▁be ▁mis - re construct ed ▁as ▁CC Q E ▁and ▁introduce ▁a ▁bias ▁in ▁the ▁re construct ed ▁neut r ino ▁energy ▁spectrum . ▁Thus , ▁it ▁is ▁essential ▁to ▁optimize ▁the ▁det ector ▁to ▁be ▁sensitive ▁to ▁additional ▁particles ▁and ▁nuclear ▁effects . ▁ ▁Three ▁main ▁measures ▁need ▁to ▁be ▁taken ▁to ▁address ▁these ▁issues : ▁ ▁The ▁det ector ▁needs ▁to ▁efficiently ▁detect ▁the ▁nucle ons ▁in ▁the ▁final ▁state ▁of ▁neut r ino ▁interactions . ▁For ▁this , ▁the ▁detection ▁th resh olds ▁need ▁to ▁be ▁lower ed . ▁ ▁High - angle ▁and ▁backwards - going ▁tracks ▁must ▁be ▁well - re construct ed . ▁This ▁is ▁achieved ▁by ▁increasing ▁the ▁angular ▁accept ance ▁and ▁the ▁efficiency ▁of ▁the ▁disc rim ination ▁back ward ▁from ▁forward ▁going ▁tracks ▁using ▁timing ▁information . ▁ ▁Finally , ▁the ▁total ▁fid u cial ▁volume ▁( the ▁mass ▁available ▁for ▁neut r ino ▁interactions ) ▁of ▁the ▁tra cker ▁part ▁of ▁the ▁N D 2 8 0 ▁det ector , ▁character ising ▁with ▁a ▁better ▁reconst ruction ▁ability , ▁needs ▁to ▁be ▁en larg ed ▁in ▁order ▁to ▁increase ▁the ▁rate ▁of ▁neut r ino ▁interactions . ▁ ▁The ▁Up grade ▁of ▁the ▁N D 2 8 0 ▁det ector ▁( ND 2 8 0 ▁Up grade ) ▁addresses ▁these ▁requirements ▁by ▁replacing ▁a ▁part ▁of ▁the ▁P 0 D ▁sub - det ector ▁with ▁three ▁types ▁of ▁new ▁sub - det ectors . ▁The ▁existing ▁down stream ▁part ,