[Halld-cal] Minutes from Bcal Readout meeting posted

[Christina Kourkoumeli]

Thank you Zisi.I slowly figured out these with Elton's help. Yes,a test 
with optical grease would be very helpful..Christine
On 6/2/2013 4:11 μμ, Zisis Papandreou wrote:
> Hi Christina:
>
> a couple of comments from me and Elton can add to it.
>
> a) it looks like bias 3 is on.  This does not power anything on the 
> inner-most row.
> b) upstream and downstream; the title above the plots that says 
> upstream or downstream refers to the placement of the LED, while raw0 
> and raw1 are the plots for the up and down stream SiPMs.
> c) It comes close to 40ns.  If one assumes that a reflection occurs at 
> the air gap between lightguide and SiPM window, then the total transit 
> time would be close to 48 ns, which seems to be consistent with what 
> we see.  However, Elton & Co will run a test (e.g. put grease on the 
> light guides in order to minimize the reflection) to verify this.  If 
> we cannot solve it this way, we can think about running Yianna's 
> GUIDEIT code after we add light guides, and do a full ray-tracing.
>
> Cheers, Zisis...
>
>
> 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 <mailto:zisis at uregina.ca>
> Website: http://kronos.phys.uregina.ca/~zisis/professional/ 
> <http://kronos.phys.uregina.ca/%7Ezisis/professional/>
>
> >>> Christina Kourkoumeli <hkourkou at phys.uoa.gr> 02/06/13 6:00 AM >>>
> Dear Elton, all,
> I am sorry I couldn't connect to the meeting yesterday from
> CERN.Concerning the results with the LED near/far ratio, I have a few
> questions:
> a) why ch 1 doesn't have any pulse?If I understood correctly from slide
> 3, a row of 10 LED's corresponds to 4 channels 1,5,9 and 13. But we only
> see pulses in 5,9 and 13.
> b) what is the differenece of raw0 and raw1?
> c) the second peak seems to be about 7 channels away but what does this
> correspond to nsec or distance?
> Cheers,
> Christine
> On 6/2/2013 1:04 ??, Elton Smith wrote:
> > Dear collaborators,
> >
> > I have posted the minutes from today's Bcal Readout meeting on the 
> wiki at
> > https://halldweb1.jlab.org/wiki/index.php/Feb_5,2013_Readout#Minutes
> >
> > Cheers, Elton.
> >
>
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