Yea - the medium sized stuff - otherwise there would not be a door
near by and never have anyone walking anywhere near the field.

I have one degree in Physics. Almost went to Wy for high Energy.

The RF - what they do is resonate the atom in quest - each has their own
frequency - and then flip an electron. This flip is indication that
this is the correct atom and this material the frequency responds to is
what was pre-determined. e.g. one sees the up/down dip on a scope -
and
yea we found some xxx. Been there done that.

Regarding the people - normally they are stripped of all and I mean all
metal.
This means for some a medical inspection of their eyes. Those with pins
in
their legs or plates in their skulls are excluded from work near the
magnet.

NMR is the stuff medical machines came from.
Much has happened in the last 40 years.

Martin
--
Martin Eastburn, Barbara Eastburn
@ home at Lion's Lair with our computer
NRA LOH, NRA Life
NRA Second Amendment Task Force Charter Founder