[Halld-cal] BCAL - Scaler Hot Channels

[Zisis Papandreou]

Hi BCAL team:

Tegan has run several investigations connected to the issue of the handful of "hot scalers" on the BCAL.  He does not see evidence for this in the ADCs of TDCs, using the plugins described below.  

As Mark suggested during our last meeting, a cable swap can would tell us whether it is the scalers that have the problem or it is in the disciminator->TDC route.

Any other ideas?  Can it be something in the plugins that masks seeing the effect? We think not, but perhaps we overlooked something.

Cheers and thanks, Zisis...

Begin forwarded message:

> From: beattite <beattite at uregina.ca>
> Subject: Hot Channels
> Date: March 23, 2015 at 1:49:15 PM CST
> To: Zisis Papandreou <zisis at uregina.ca>
> 
> Using a version of the DAQTreeBCAL plugin, we don't see increased number of events in the 'hot' channels from the ADC (BCALdigi tree) or from the TDC (BCALTDCdigi tree).  The 'w_integral' (integral of the waveform) distributions for the 'hot' channels compared to normal channels seem to be indistinguishable.  The waveforms, as well, look the same.
> 
> As Elton suggested, we might not see the effects of the hot channels in the ADCs if there's something going on in the TDC line.  But, it is odd that the scalars see huge rates for these channels while the TDC is not recording an increased number of events if the input for both is coming from the same discriminator.
> 
> If we could do some cable-swapping tests like Mark mentioned at the last meeting, that might be best for trying to figure out what's happening.


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://www.uregina.ca/science/physics/faculty-staff/faculty/zisis-papandreou.html





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