Hi Dave,
We installed this cross piece on our D205 cryostat (unshielded 400 MHz) a
couple years ago. We had to slightly rotate one of the cryostat helium turrets
at the base to align the two helium exhausts, and the rest of the installation
went smoothly.
Best,
Sameer
--
Sameer Al-Abdul-Wahid, Ph.D.
Manager, Nuclear Magnetic Resonance Centre
http://nmr.uoguelph.ca/
University of Guelph
519-824-4120 x58914 / s.wahid_at_uoguelph.ca
> From: main_at_ammrl.groups.io on behalf of Michael Groves via groups.io
> Date: Tuesday, January 27, 2026 at 17:25
> To: main_at_ammrl.groups.io
> Subject: Re: [AMMRL] helium plumbing on vintage Bruker magnets
Hi David,
I don't know what the D number of your magnet is--you can check that on the
base plate. Here's what I have regarding replacing the existing manifold
depending on the D number of your magnet.
Cheers,
Mike
On Tuesday, January 27, 2026 at 01:30:11 PM MST, Vander Velde, David via groups.io wrote:
Hi, I am now involved in managing a Bruker Ultrashield magnet (which I had
previously done decades ago) after a period of managing Ascend magnets. Prior
to the Ultrashield series, every magnet I worked with (Oxford or Spectrospin)
had a cross piece connecting however many helium stacks there were, with a
small one way valve on the single vent.. The Ultrashields came without this
piece, with just Tygon tubing connecting the stacks to a similar one way
valve. With the Ascend series, the cross piece came back, with a much more
robust one way valve which can stay in place during helium fills. (pictures
attached)
I took care of Ultrashields for quite a while without understanding why the
cross piece went away, or what the really optimal way was to vent the cold
gas released during a helium fill. The two stacks on the mid field magnets
behave very differently--the one with the fill port and the helium sensor
appeared to be wide open to exiting helium, whereas the other stack was
extensively set up with baffles or other internal structures which impeded
the helium.
I have a very strong preference for filling magnets that feature the cross
piece, where how much helium is exiting through which stack is transparent
to me.
My questions are, has anyone modified their UltraShield with the Ascend style
cross piece? Alternatively, does anyone know of reasons why that would be a
bad idea?
--
Dave VanderVelde
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Received on Wed Jan 28 2026 - 04:42:15 MST