https://en.wikipedia.org/wiki/Boson

"multiple identical composite bosons (in this context sometimes known as 'bose particles') behave at high densities or low temperatures in a characteristic manner described by Bose–Einstein statistics: for example a gas of helium-4 atoms becomes a superfluid at temperatures close to absolute zero."

Helium leaks as nothing else, even more than hydrogen.

Here's some leak rates of heilum: https://www.researchgate.net/figure/Comparison-of-the-helium...

Let's say we have a um^3 of helium in the device proposed. Let's assume leak rate of 8*10^-9 of cm^3/sec. (1e-6/1e-2)^3/(8e-9) is equal to 1.2499999999999998e-4 - all helium will leak in 1/8 of microsecond in the device proposed.

I hope this helps.

this is a but solly, like saying you will eventually have a fridge the size if a m9bile phone - us it usefull?