sPHENIX HCal discussion

["W.A. Zajc" <zajc AT nevis.columbia.edu>]

Hi Martin:

Beautiful signals, great news!

I may use the movie for a screen saver.

Now that the set-up is working, it will be interesting to move the lower paddle back to underneath the entire HCal, to see what the rate is and to better localize muons in a given tower. 

Best regards,

Bill 

—————————————————

W.A. Zajc
I.I. Rabi Professor of Physics
Columbia University
New York, NY 10027

https://blogs.cuit.columbia.edu/waz1/
—————————————————

On Mar 29, 2022, at 6:01 PM, Martin Purschke via sPHENIX-HCal-l <sphenix-hcal-l AT lists.bnl.gov> wrote:

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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