Re: Design Report

From: Richard Hahn <>
Date: Thu Jul 15 2004 - 10:19:48 CDT

Let's not forget either that SNO had an industrial cosnultant who was a specialist on acrylic and its compatibility with many different chemicals. He often ran ASTM-type tests to search for chemical attack, crazing, production of stresses in the acrylic, before he would give a particular chemical his seal of approval for use in SNO. There is a thick report about the results of the tests that is available from SNO (Peter Doe or Davis Earle). Many seemingly innocuous chemicals, such as ethanol, are on the forbidden list. So let's not be too cavalier about the kinds of liquids that we think we can put into long-term contact with acrylic. I personally am dubious about the suitability of PCH, even though colleagues have told me that simple tests that they have done look OK. PC is definitely a No-No.

Steve Biller <> wrote:

Hi Vic & company,

Thanks for the nice start on the design report! Sorry for the late
response to this, but here are a few more notes on acrylic:

First, one minor thing: at one point the report says SNO used
polycarbonate... we didn't, we used acrylic. This seems to be
corrected later on in the report.

Yes, the endothermic reaction in the bonding process is a
very big deal... probably the central issue in putting
something like this together. Large pieces will not necessarily
make the job easier and may even make it more difficult.
This is because more heat is generated in larger bonds and
you have to make sure all the acrylic in the vicinity of the
entire bond is well maintained at the same elevated temperature
(using heating tapes etc.). You also need jigs to hold
each piece very carefully and securely in place during the
bonding procedure. I note that this whole business was one
of the main reasons for the delay in construction of SNO.

By all means, go and talk to Reynolds. However, we found that,
while they could certainly produce the panels, even they
did not have the necessary expertise when it came to handling
the bonding. Accordingly, you should also talk to the following
people from SNO:
Peter Doe (
Davis Earle (
Mick Williams (

I'm willing to bet such discussions will definately put you
off the idea of having a 3rd region! Fortunately, a consensus
seems to be emerging that this will likely not be necessary.
My understanding is that the design would then be for
something close to the larger of your two spheres for an
overall bigger fiducial volume... but we'll probably hear
more detail of this at the next meeting.

The size of the neck should probably also be considered in
more detail. Do we want it big enough to allow manual
entry? Finishing/sanding the acrylic bonds might possibly be
one reason - could there be others? What is the maximum size
calibration source we may want to deploy? What are the
actual, quantitative disadvantages of a wider neck?

Any ideas for the PMT support structure? Particularly given
that we're actually thinking about moving these monsters
around, do we have to worry about SuperK-like catastrophies?


- Steve

----- Original Message -----
From: "David Reyna"
Cc: "Victor Guarino"
Sent: Thursday, July 01, 2004 2:49 PM
Subject: mechanical design work

> Greetings,
> While at Oxford, Ed mentioned that it's been a while and we should
> probably have a Braidwood get together/collaboration meeting in the
> relative near future. With that in mind I wanted to let everyone know
> about a draft baseline detector design document that Vic Guarino has
> been assembling here at Argonne. We have been trying to look into all
> of the issues involved with design, assembly, installation and operation
> of a baseline detector and intend to present this for more detailed
> review and revision at the next collaboration meeting. At this
> time, the document is still a work in progress with several sections
> still needing to be fleshed out, but we would like to encourage any
> interested parties to take a look now and provide feedback or comments.
> The document can be found at
> Regards,
> -Dave
Received on Thu Jul 15 10:19:54 2004

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