Re: Readout crates in counting house?

[Elliott Wolin <wolin@jlab.org>]

Hi Paul,

> Even with preamps, you would lose timing resolution.  Maybe this wouldn't be so 
> bad.
>
> Cost would be a big issue.  There are ~30K channels.  Assume 25 
> cents/foot/signal and each foot away from the detector costs $7500.  Your 50 
> feet would cost $375K.


I believe (hope?) that we could avoid losing resolution by using good cables,
and that cable length could be kept to a minimum.  I agree it will cost more,
but it may be worth it.  Does it really cost 25 cents/foot/signal?


> I agree strongly with you about wanting access to crates while beam is on.  How 
> about shielding the detector with concrete blocks and having the crates just 
> outside this shielding?  Or, how about turning the beam down low enough to allow 
> crate access during setup but not during actual running?


Having the crates "virtually" in the counting house, i.e. outside the radiation
area, is perfectly acceptable...we'd only need 10cm concrete shielding for full
access (e.g. the crates could be along the walls of the building).

I doubt JLab will let anyone into the hall with the beam on.


				Sincerely,
					Elliott
 

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