Hi,
Not much to add to what Charlie wrote but this: please check if you have
normal helium exhaust coming out of the helium check valve, also carefully
try to remove both helium baffle sticks (might be stuck - don’t apply any force if
it is!) and put a temporary plug/bung on top of the open helium turret until
you have warmed up the baffle stick before re-inserting it.
In case one or both baffle stick(s) is stuck you may have found the
culprit of your magnet drift (overpressure in helium dewar raises the helium
bath temperature, making the wire less superconducting) should
try to un-stick it using helium gas (may call in a magnet expert for this if you
haven’t done this before), probably going in from the check valve that
the baffle stick should have (Oxford magnet) should check all
helium-facing O-rings as you likely have a leak where air getsin and freezes
further down in the helium necks
Best regards & good luck,
Bert
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