

New ones, and not all if them, work this way, as in there’s tiny helium condensing unit. Older ones just let it go and require topping up every couple months (guessing by how often helium in NMR is topped up). Also every emergency shutdown invariably blows off all of helium inside













The one we can mine is drawn off together with natural gas, and was produced over geological timescales as product of alpha decay of uranium