sPHENIX HCal discussion

["Lajoie, John G [PHYSA]" <lajoie AT iastate.edu>]

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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