> I wouldn't worry too much about safety once its small, there is minimal amount of harm caused by ultra cold or ultra high vacuum
In a previous life I worked with NMR machines, the ones with superconducting magnets cooled by liquid helium which is itself cooled by liquid nitrogen.
I would dispute "minimal amount of harm", part of the our training involved what to do if the magnet quenches, I recall "run for the exit before you suffocate" was basically the SOP...
Anyway, they were loads of fun to work with, I won't ever forget that time I nearly had my house keys snatched out of my hand by one, but back then (25 years ago) they occupied entire rooms. AFAIK they still do.
OT but I had an MRI a couple of weeks ago, and forgot to take off my gold wedding band. I could distinctly feel the magnetic field pulsing in my ring as the scan started. After a brief moment of sheer panic I realised it wasn't a problem ... and as I lay there I was idly wondering about just how much gold was in my ring :)
> I would dispute "minimal amount of harm", part of the our training involved what to do if the magnet quenches, I recall "run for the exit before you suffocate" was basically the SOP...
Yes, at current scale it would be very hazardous, but at miniature scale a gram of liquid helium could do how much damage considering it would have to make its way through the internals of a machine to contact skin?
In a previous life I worked with NMR machines, the ones with superconducting magnets cooled by liquid helium which is itself cooled by liquid nitrogen.
I would dispute "minimal amount of harm", part of the our training involved what to do if the magnet quenches, I recall "run for the exit before you suffocate" was basically the SOP...
Anyway, they were loads of fun to work with, I won't ever forget that time I nearly had my house keys snatched out of my hand by one, but back then (25 years ago) they occupied entire rooms. AFAIK they still do.
OT but I had an MRI a couple of weeks ago, and forgot to take off my gold wedding band. I could distinctly feel the magnetic field pulsing in my ring as the scan started. After a brief moment of sheer panic I realised it wasn't a problem ... and as I lay there I was idly wondering about just how much gold was in my ring :)