Temperature test FCAL plastic (fwd)

[Elton Smith <elton@jlab.org>]

---------- Forwarded message ----------
Date: Tue, 29 Jan 2008 09:31:39 -0500
From: beni zihlmann <bzihlman@indiana.edu>
To: Tim Whitlatch <whitey@jlab.org>, Matthew Shepherd <mashephe@indiana.edu>,
     Elke-Caroline Aschenauer <elke@jlab.org>, Elton Smith <elton@jlab.org>
Subject: Temperature test FCAL plastic

Hi Tim,
The temperature test I did came out negative. Meaning I did not
sea any measurable temperature increase while running 4 PMTs
at 1800 Volts.

4 holes are drilled into the high density plastic. the plastic is about
16cm thick. The bases stick out in the back of the plastic by 5 cm
the PMTs stick out in the front of the plastic by about 6 cm.
The BASES are powered up to 1800 Volts and signals are seen on the
PMTs. (The PMTs are covered with black plastic to shield light.)
A temperature is inserted into the hole and located next to a PMT
such that it is separated by the thin wall of plastic from the neighbouring
PMT. At some point a cover was put over the whole assembly to prevent
air exchange (cooling). In all cases over a time period of 1 week I did not
see any temperature change withing the accuracy of the measurement.

I think the conclusion is that high density plastic is a viable option.

cheers,
Beni