Re: Magnet location

Jeff Walton (jhwalton@ucdavis.edu)
Wed, 16 Dec 1998 13:18:08 -0800 (PST)

This depend on the vibration isolation system you have on your magnets. We
just got a new DRX-600 with a Magnex Magnet and it's vibration dampers are
very good. Note that we are on the graound floor and still have
significant vibrations in the 10 to 30 Hz range as evidenced by taking the
magnet off the dampers (shutting off the air supply). With the dampers on
there is a little modulation under 1 Hz but nothing over that. And our
linewidths at the base are seldom less than 1 Hz. I guess I don't know
whether to credit Bruker or Magnex, but they work as Bruker advertised.
Our older Oxford 500 supplied by GE, on the other hand, does not have very
good dampers (although they may just be old). Bruker has supplied us with
new dampers (of a different design, the "rubber tire" Chris mentioned) but
they have yet to be installed. Note: We can trace a large amount of our
vibration to the Animal Cage Cleaning Facility that occupies the other half
of our building. So one important thing to take into consideration is what
else will be in the building.

I guess in summary, 1) NO vibrations is best, 2) Don't assume the ground
floor will be vibration free, and 3) Good vibration dampers will make a
difference.

Good Luck!

Jeff

> We are in the process of designing a new addition to our building and
>there are those who would have me relocate the nmr lab from its current
>location in the basement to the third floor of the new building. Since I
>have always thought that cryomagnets should be located on a vibration free
>surface, this suggestion disturbs me. Are there any of you who have any
>opinions/horror stories/suggestions concerning this topic?
>
>Keith Brown
>University of Saskatchewan
>Saskatoon, Saskatchewan
>
>------------------------------------------------------------------------
>Pinky: What shall we do tonight, Brain?
>Brain: The same thing we do every night, Pinky ... try to take over the
>world!

Jeffrey H. Walton
Assistant Research Physicist
One Shields Ave.
UCD NMR Facility
University of California
Davis, CA 95616
(530) 752-7794 (office)
(530) 754-9064 (lab)
(530) 752-8109 (FAX)
jhwalton@ucdavis.edu
NMR Facility URL http://www.nmr.ucdavis.edu

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