▁of ▁oscill ation ▁parameters ▁measured ▁by ▁the ▁Super - K ami ok ande ▁det ector ▁for ▁atmos pher ic ▁neut r inos . ▁ ▁The ▁construction ▁of ▁the ▁neut r ino ▁beam line ▁started ▁in ▁ 2 0 0 4 ▁and ▁it ▁was ▁successfully ▁commission ed ▁in ▁ 2 0 0 9 . ▁Const ruction ▁of ▁the ▁entire ▁IN GR ID ▁det ector ▁and ▁majority ▁of ▁the ▁N D 2 8 0 ▁det ector ▁( without ▁bar rel ▁part ▁of ▁the ▁elect romagnet ic ▁cal or imeter ) ▁was ▁completed ▁in ▁ 2 0 0 9 . ▁The ▁missing ▁part ▁of ▁the ▁cal or imeter ▁was ▁installed ▁in ▁the ▁fall ▁of ▁ 2 0 1 0 . ▁T 2 K ▁far ▁det ector ▁is ▁the ▁large ▁Super - K ami ok ande ▁det ector , ▁which ▁has ▁been ▁running ▁since ▁ 1 9 9 6 ▁and ▁studying ▁pro ton ▁lifetime ▁and ▁oscill ations ▁of ▁atmos pher ic , ▁solar ▁and ▁acceler ator ▁neut r inos . ▁ ▁T 2 K ▁experiment ▁started ▁to ▁take ▁neut r ino ▁data ▁for ▁a ▁physics ▁analysis ▁in ▁January ▁ 2 0 1 0 , ▁initially ▁with ▁an ▁incomplete ▁N D 2 8 0 ▁det ector , ▁and ▁starting ▁from ▁November ▁ 2 0 1 0 ▁with ▁the ▁full ▁setup . ▁The ▁data ▁taking ▁was ▁interrupted ▁for ▁one ▁year ▁by ▁the ▁Great ▁T oh oku ▁Earth qu ake ▁in ▁March ▁ 2 0 1 1 . ▁The ▁pro ton ▁beam ▁power , ▁and ▁thus ▁the ▁neut r ino