[Halld-cal] BCAL update

[Zisis Papandreou]

Hello Elton:

thank you for the detail reporting on the BCAL.  It helps us here in Regina to keep abreast of the progress.  

It looks like you've encountered "standard" pains of turning on a system of this size.  Funny about the conductivity of the splash guards, though.

Anyhow, Andrei and I are scheduled to be there early Monday morning (March 17); we both have to update our RadWorker I training, but that won't take long, and then we'll be ready for action.   It would be useful to touch base by this coming Thursday to plan a rough list of tasks that can be tackled when Andrei and I are there.  We are happy to work on channel checking, but we would also like to make sure the cosmics setup is done, and prove it at least with one pair of modules those at 90 and 270 degrees (top one and bottom one).  Also, we should explore the option of us assisting with analysis while we are in Regina, in order to ease the load of what you guys have and propel the testing forward -- of course, once we have the DAQ going (Alex, will we have something to use when we are at JLab, week of March 17-221?). Plus, anything else needed to be done.

Cheers, Zisis...

P.S.  I have not been able to find an apartment yet for the students -- but I hope that some might become available soon.  Some rental companies have a 60 day notice, so we should find out soon when apartments are released by their current occupants.


On Mar 7, 2014, at 4:37 PM, Elton Smith <elton at jlab.org> wrote:

> Hi all,
> 
> I thought it is worth sending a brief update on the status of BCAL 
> checkout, especially since the GlueX meeting was cut short.
> 
> A week ago we started turning on the BCAL and immediately found that 
> most (~75%) of all channels would not hold HV (i.e. 75 V), This problem 
> was traced to the cables that run from a distribution panel to the 
> module and deliver the HV and LV power to the module. The specific 
> problem was a rubber sleeve inside the connector assembly that made the 
> connectors "splash proof." This sleeve often turned out to be conductive 
> with a resistance in the range of 50-100 kOhm and caused leakage from HV 
> to LV and vice-versa. Fernando will be consulting with the factory 
> regarding the specifications of the sleeve and whether the conductivity 
> is from a bad batch or a known problem. In any case, the good news is 
> that the sleeve is not needed for our purpose and they have been cut out 
> of the cables on the upstream modules (the downstream will be 
> scheduled). Following the fixing of the cables, I have checked signals 
> on all upstream modules. Here is a quick status for the upstream 
> (downstream is not yet ready for testing):
> 
> * The upstream chiller has been operating for about a week now and is 
> keeping the upstream cooling plates at about 18 deg C.
> * The RTDs on the cooling plates read within 1 degree of each other 
> (except for 3 problems)
> * The N2 system is keeping the system dry. The humidity ranges from 1.3% 
> to 20% (corresponding dew points: -34 degC and -3 degC)
> * The EPICS slow control GUIs are working correctly with the expected 
> map between HV and LV levels and detector elements.
> * M33 has the "sleeve" symptom and must have been missed. (Will be 
> repaired Monday).
> * M46, V1 trips and M13, V2 trips. Neither trip when the module is 
> disconnected. We will investigate these further on Monday and may need 
> to remove the readout assemblies to fix the problem.
> * Signals A0-A7 of every module were checked on the scope for noise. 
> Three signals were missing.
> 
> Cheers, Elton.
> 
> 
> 
> -- 
> Elton Smith
> Jefferson Lab MS 12H5
> 12000 Jefferson Ave STE 16
> Newport News, VA 23606
> (757) 269-7625
> (757) 269-6331 fax
> 
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Dr. Zisis Papandreou
Professor of Physics, Ph.D, P.Phys.
---------------------------------------------------------
Department of Physics   
University of Regina	    
3737 Wascana Parkway
Regina, SK  S4S 0A2	 CANADA

Phone: (306) 585-5379
Fax: (306) 585-5659
Email:  zisis at uregina.ca
Website: http://kronos.phys.uregina.ca/~zisis/professional/




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