sPHENIX HCal discussion

["Kistenev, Edouard" <kistenev AT bnl.gov>]

Martin, 

to me probably the most important proof of principle - you see the signals in two neighboring channels - even if this is the part of calorimeter predominantly hit "along" the radii. This is our 4 tiles out of 5 tower-to-tower overlap which allows (if one is smart) to find from OHCal data where exactly it was hit and how the shower energy is distributed longitudinally and compute actual shower LCG in a single longitudinal section. In general this means that we have more then 3 longitudinal sections in the whole calorimeter - this particular design feature was so many times explained and ignored until now - maybe this dance of samples will help to promote the idea.

Thank you

Edward

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From: sPHENIX-HCal-l <sphenix-hcal-l-bounces AT lists.bnl.gov> on behalf of Lajoie, John G [PHYSA] via sPHENIX-HCal-l <sphenix-hcal-l AT lists.bnl.gov>
Sent: Tuesday, March 29, 2022 6:21 PM
To: Purschke, Martin <purschke AT bnl.gov>; sphenix-hcal-l AT lists.bnl.gov <sphenix-hcal-l AT lists.bnl.gov>
Subject: Re: [Sphenix-hcal-l] cosmics in the HCal

 

Hi Martin,

Awesome progress, Martin - this is really amazing to see!

John

-----Original Message-----
From: sPHENIX-HCal-l <sphenix-hcal-l-bounces AT lists.bnl.gov> On Behalf Of Martin Purschke via sPHENIX-HCal-l
Sent: Tuesday, March 29, 2022 5:02 PM
To: sphenix-hcal-l AT lists.bnl.gov
Subject: [Sphenix-hcal-l] cosmics in the HCal

All,


we finally got everything together to really time the HCal in properly.
I usually put a short copy of the trigger signal on a channel and tweak the delay until I see it at the right spot in the waveform.

Dan found, after the telescope had been moved and adjusted slightly, that the detector signal came about 150ns before the trigger.

My trigger copy sat 100ns *after* the trigger. So when we see that signal at sample n, the real HCal signal would be at about sample n-15.

We played with the delay settings and made it so that the trigger copy sits at 25 to get 10 with real data. And it worked. After now seeing the real pulses, we nudged the delay a bit more and the signal looks beautiful. And we see a signal in a bit more than half the events now.
There remain plenty of pathways for a cosmic to hit both paddles and still miss the sector, but often it hits.

This is run 100. Also see note
https://sphenix-intra.sdcc.bnl.gov/WWW/elog/HCAL/1438

The "persistency plot" that I showed in the HCal meeting this morning before the timing adjustment now shows what we expect, attached.

Also, if you like to see something cool, point your browser at

http://www.phenix.bnl.gov/~purschke/hcal/hcal2.avi

or, if you have a Mac,

http://www.phenix.bnl.gov/~purschke/hcal/hcal2.mov

Best,
        Martin


--
Martin L. Purschke, Ph.D.        ;   purschke AT bnl.gov
                                  ;   http://www.phenix.bnl.gov/~purschke
                                  ;
Brookhaven National Laboratory   ;   phone: +1-631-344-5244
Physics Department Bldg 510 C    ;   fax:   +1-631-344-3253
Upton, NY 11973-5000             ;   skype: mpurschke
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