▁water ) ▁than ▁the ▁Super - K ami ok ande ▁det ector . ▁It ▁will ▁be ▁a ▁cyl inder ▁of ▁ 7 4 ▁meters ▁diameter ▁and ▁ 6 0 ▁meter ▁height ▁with ▁ 4 0 0 0 0 ▁phot om ult ip lier ▁tub es ▁of ▁ 5 0   cm ▁diameter ▁and ▁ 6 7 0 0 ▁phot om ult ip lier ▁tub es ▁of ▁ 2 0   cm ▁diameter . ▁It ▁will ▁be ▁located ▁ 8   km ▁south ▁from ▁the ▁Super - K ami ok ande ▁det ector ▁in ▁the ▁To ch ib ora ▁mine , ▁ 6 5 0 ▁meters ▁under ▁the ▁peak ▁of ▁N iju ugo ▁mountain , ▁at ▁the ▁same ▁off - axis ▁angle ▁( 2 . 5 ° ) ▁to ▁the ▁neut r ino ▁beam ▁centre ▁and ▁in ▁the ▁same ▁distance ▁( 2 9 5   km ) ▁from ▁the ▁beam ▁production ▁place ▁at ▁J - PAR C . ▁The ▁start ▁of ▁the ▁H K ▁det ector ▁construction ▁is ▁planned ▁for ▁ 2 0 2 0 ▁and ▁the ▁start ▁of ▁data ▁collection ▁is ▁expected ▁in ▁ 2 0 2 7 . ▁ ▁Inter mediate ▁Water ▁Ch eren kov ▁ ▁The ▁Inter mediate ▁Water ▁Ch eren kov ▁Det ector ▁( I W CD ) ▁will ▁be ▁located ▁at ▁a ▁distance ▁of ▁ 0 . 7 – 2   km ▁from ▁the ▁neut r ino ▁production ▁place . ▁It ▁would ▁be ▁a ▁cyl inder ▁filled ▁with ▁water ▁of ▁ 1 0 ▁m ▁diameter ▁and ▁ 5 0