[Halld-cal] Bcal Readout meeting tomorrow

[William Brooks]

Dear Elton, 

 I'm at the PANIC conference in Boston. However, I did try for an hour to connect to the meeting, through ESNET, EVO, etc., but was never able to get a stable connection. 

Our report: 

Prototype boards: both boards fully stuffed with components, fully tested with current injection pulses, and mounted on the dark box, following installation of the 4 patchthrough boards. Light-based measurements, with cooling circuit active, will begin this week. 

Some small areas of the boards are not working. The amplifiers work fine, but some pins of a few multiplexers don't seem to have good connection. The belief is that there are bad solder joints on a few pins. This will be investigated further this week, but it does not prevent light-based testing.

Currently we can test 8 MPPCs at once. 

The 10 MPPCs on loan from JLab arrived with no visible damage. There was a long holdup in customs.

The new, more modular boards are under construction. These hold 8 amplifiers and 1 multiplexer. We could fabricate some for JLab tests if desired.  Using those, the big board only has traces, some logic, and power supplies. This will allow for faster switchouts of components when needed.

PDE measurements setup:
Light mixer has been prepared - splits light uniformly from 1 clear fiber to cylinder 60 mm diameter x 100 mm length, with the far end painted with white paint. 18 green fibers, with depth 20 mm, implanted into the same end as the clear fiber, so light bounces at least once before hitting the 18 green fibers. Performance will be tested starting this week.

Thanks, 

 - Will


On Jul 25, 2011, at 5:00 PM, Elton Smith wrote:

> Hi all,
> 
> Quick reminder of our Bcal Readout meeting tomorrow. I have added Athens 
> to the agenda, as we may need to discuss final updates to geometry 
> features on the light guide and/or response to the JLab RFP.
> 
> Cheers, Elton.
> 
> 
> 
> = Tentative Agenda =
> 
> # Announcements
> # Review of Action Items
> # Monitoring Update (Athens)
> # USM Update
> # SiPM update
> # Electrical/cooling (Elton)
> # Geometry and light guides
> # Simulations
> 
> -- 
> Elton Smith
> Jefferson Lab MS 12H5
> 12000 Jefferson Ave
> Suite #16
> Newport News, VA 23606
> (757) 269-7625
> (757) 269-6331 fax
> 
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