From: Jonathan Link (link@fnal.gov)
Date: Thu Jun 23 2005 - 17:04:07 CDT
Hi Dick,
Last summer we had an engineer here at Fermilab do a fluid dynamics
calculation of maintaining the temperature of the inner volume by
flowing chilled fluid in the buffer. This was shown to be very
effective at maintain the target temperature (even with relatively low
flow rates. The calculation assumed going from a fixed temperature
underground to one that was 20 degrees (I think) higher at the surface
and staying there for one full 24 hour period. At any rate the details
of exposure are not important because it turned out that one could
maintain that inner temperature indefinitely. As for electronics, based
on our experience with MiniBoone one must maintain the flow of cooling
air or the temperature can change quite rapidly. Similarly, when one
wishes to cool the electronics (say after an HVAC failure) it happens on
a time scale of minutes.
-Jon
Hahn, Richard wrote:
>I heard through the grapevine that someone on NuSAG had asked how Braidwood
>could ensure that the detectors would remain "identical" after the move,
>when at minimum there will have been changes in the temperature of the
>detector liquid, the electronics, etc., by moving from underground to the
>surface, transporting on surface, and then moving back underground. Imagine
>this move happening in Illinois in mid winter, or mid summer. Has anyone
>addressed this issue? Is there any characteristic minimum time period that
>we would have to wait after the move, to have thermal equilibrium
>reestablished in the detector components? Can any of these effects be
>calculated? What kind of temperature swings might we expect? What is the
>expected ambient temperature underground at 450 mwe?
>
>Dick
>
>-----Original Message-----
>From: Yeh, Minfang
>Sent: Thu 6/23/2005 1:03 PM
>To: Ed Blucher; braidwood@hep.uchicago.edu
>Cc:
>Subject: Re: Braidwood template for response to NuSAG
>
>
>Hi
>
>The statement for NuSAG question #3 is attached for your comments. I didn't
>have time to put them in the template that Mike and Ed provided, but the
>final version will.
>
>Minfang
>
>*********************************
>Minfang Yeh
>Brookhaven National Laboratory
>Chemistry-555
>Upton, NY 11973
>Tel: 631-344-2870
>Fax: 631-344-5815
>*********************************
>
>
>----- Original Message -----
>From: Ed <mailto:blucher@hep.uchicago.edu> Blucher
>To: braidwood@hep.uchicago.edu <mailto:braidwood@hep.uchicago.edu>
>Sent: Wednesday, June 22, 2005 3:00 PM
>Subject: Braidwood template for response to NuSAG
>
>
>Please use the attached template for drafting responses to the NuSAG
>questions. We'll discuss all of the questions at tomorrow afternoon's
>phone meeting.
>Mike and Ed
>
>
>
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