Re: Power dissipation inside solenoid (planacon solution) (fwd)

[Elton Smith <elton@jlab.org>]

Hall D barrel calorimeter:



---------- Forwarded message ----------
Date: Tue, 27 Feb 2007 10:55:53 -0500
From: Carl Zorn <carl.zorn@jlab.org>
To: Elton Smith <elton@jlab.org>
Subject: Re: Power dissipation inside solenoid (planacon solution)

Tuesday, Feb. 27, 2007

Concerning the planacons, Vladimir Popov has estimated a reasonable
figure for power dissipation.
He has worked on a multi-planacon detector that involves an array of
16 64-channel planacons plus
the associated amplifier boards.  This would make for a good
comparison.  The bottom line is about 2 watts
per PMT plus a high estimate of 1 watt per amplifier board (1 board
per PMT).  So that gives 3 watts per
PMT.  (Vladimir also pointed out that an alternate amplifier design
could easily reduce the 1 watt by at least a
factor of 10).  So it looks like we should be able to keep it under
600 watts total.


...............Carl


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On Feb 27, 2007, at 9:06 AM, Elton Smith wrote:

>
> Hi Tim,
>
> I am trying to estimate the total amount of heat dissipated by
> electronics
> inside the solenoid. The most confined space is for the FDC, which has
> been the subject of most of the cooling studies. The CDC
> electronics is
> located upstream and even though it is inside the magnet, there is
> open
> space between the CDC and the UPV. This is also true for the
> upstream Bcal
> electronics. The downstream Bcal electronics are a little more
> confined
> by cabling obstructing the downstream openning of the magnet.
>
> Estimate:
>
> Assume 0.4 W per 8-ch ASIC chip. This is a fairly reliable estimate
> for
> the chip.
>
> CDC 3200 ch/8 x 0.4 W = 160 W
> FDC 11,520 ch/8 x 0.4 W = 580 W
>
> Assume 10 W per 16-ch SensL module. This is a guesstimate from Paul
> Smith
> based on the cooling power of the 3x3 SiPM of 1 W.  It is probably
> correct
> within a factor of 2.
>
> Bcal upstream 3072/2 ch x 10 W/16 = 960 W
> Bcal downstream 3072/2 ch x 10 W/10 = 960 W.
>
> Alternative readout: If we assume the same number of channels
> (3072) and
> 16 channel segmentation of the planacon tubes, with a typical
> consumption
> for the planacon divider of a few W, then the power dissipation
> would be
> about 5 times lower. Carl can comment on the validity of this
> assumption.
>
> Cheers, Elton.
>
> Elton Smith
> Jefferson Lab MS 12H5
> 12000 Jefferson Ave
> Suite # 16
> Newport News, VA 23606
> elton@jlab.org
> (757) 269-7625