Yes, administrative segregation; I'll call it solitary confinement.
I've been to several prisons in the last year, as I was ten years prior, so I've been renewing my visits. The increased amount of gang activity in the penitentiaries is phenomenal, just amazing.
When checking on the solitary confinement areas, or administrative whatever-you-call-it, they're full almost all of the time. And most of them are full because of requests from the inmates, not because they're being punished and sent there; most of the inmates are there at their own request, for protection.
Is there quite an additional cost when you fill up your segregated units?