sPHENIX EMCal discussion

[Stefan Bathe <stefan.bathe AT baruch.cuny.edu>]

Hi Craig,

I agree with everything you say.

My point was that the linear T dependence (as in John’s plot) mathematically leads to different relative gain changes per degree for different temperatures.  At T = 26 C (Hanpu’s reference temperature) it is 3.1 % per degree C.  At T = 0 C (probably Hamamatsu’s reference temperature?) it is 1.7 % per degree C.—No contradiction there.

We translated the linear T dependence to a relative change around 26 C b/c that was our typical ambient temperature in 912.

Regards,

Stefan

- 

---------------------------------------------------------------------------------
Stefan Bathe

Professor of Physics
Baruch College, CUNY
and RIKEN Visiting Scientist

Baruch:                                     BNL:
17 Lexington Ave                      Bldg. 510
office 940                                  office 2-229
phone 646-660-6272                phone 631-344-8490
----------------------------------------------------------------------------------

On Jan 19, 2022, at 15:48, Craig Woody <woody AT bnl.gov> wrote:

Hi Stefan,
 I do believe that the temperature coefficient published on the Hamamatsu Data Sheet does represent the true temperature dependence of the device, which agrees with several different ways we have measured it our self, either in our lab or in situ with the EMCAL. However, as you point out, it may depend on the fit range of the data, but probably even more so on how the temperature is measured. I think under very controlled conditions (like in Sean's thermal oven in his lab), or even in our EMCAL with the chiller in full operation, we've achieved pretty good thermal equilibrium and have gotten reasonably good agreement with the Hamamatsu Data Sheet. However, if the temperature you use to try and determine the temperature dependence doesn't really represent the true temperature of the SiPM itself, it can lead to very misleading results.

Cheers,
Craig

On 1/19/2022 3:28 PM, Stefan Bathe via sPHENIX-HCal-l wrote:

Hi John, Craig, and All,

Just to follow up on the T dependence discussion regarding the difference between a T coefficient in the 3 % range and the ~1.5 % you mentioned towards the end of the meeting:  this must depend on the reference temperature.

If I take the fit parameters from your slides, John (March 12, 2021, EMCal meeting):

S(T) = -25.57*T + 1483

and calculate S(26) and S(20) from that, and then insert that into Hanpu’s formula from today’s meeting:  S(T) = S(26)*(1 - alpha(T - 26)) for T = 20, I get:

alpha = 0.03125.

Regards,
Stefan
-
---------------------------------------------------------------------------------
Stefan Bathe
Professor of Physics
Baruch College, CUNY
and RIKEN Visiting Scientist

Baruch:                                     BNL:
17 Lexington Ave                      Bldg. 510
office 940                                  office 2-229
phone 646-660-6272                phone 631-344-8490
----------------------------------------------------------------------------------

On Jan 19, 2022, at 02:29, Frantz, Justin via sPHENIX-software-l <sphenix-software-l AT lists.bnl.gov> wrote:

Hello,

Reminder our first Calo Calibrations meeting will later today at 1pm.  So far I am on the agenda, unless Megan had similar plans, I will be leading a discussion on an intro to the meeting group, as well as some of my own proposals for updating the general reco framework for the calos.  I would also like to give another whole presentation on the tower slope method updates.  It would be great if some of the folks leading some of the calo calibrations/reco efforts  (e.g. LED's, Cosmics, Pulse fitting beyond's Maxims latest update, etc.) might be ready to give at least a verbal update--and let Megan and I know if you would like to be put on the agenda.

-Justin

Agenda link:
https://urldefense.proofpoint.com/v2/url?u=https-3A__indico.bnl.gov_event_14421_&d=DwIFAw&c=dTXc8cCP8suVpClwB1HRHQACHN4UFMgL7MtSjCbKyts&r=VpzLtnjcGB03vfJuG_p478bcDf7zDOFn2OeUM-jusdY&m=K98nquVk5pj-VJK_QgNA7Xf--tHe0ney1NlxoiwSFqU&s=oVB8Xx_6Tt0p8JCNmkDQcSNWxeKQtG-LGvZRdFd3XMQ&e=


Zoom info:
Topic: Calorimeter Calibrations Meeting  (Wed)
Time: Jan 19, 2022 1 PM Eastern Time (US and Canada)

Join Zoom Meeting
https://urldefense.com/v3/__https://us02web.zoom.us/j/83101077810?pwd=YldkK200RERxTmlINFh5T3pnbHRxQT09__;!!P4SdNyxKAPE!XA4oSvY23CVUJjc7HvctfHru_SIn9JlE8zNiSidEBBw4O-hXlyh5qpjJGPsje348dtHY4n8T7DxnCQA$

Meeting ID: 831 0107 7810
Passcode: 1008



----------------------------------------------
Justin Frantz, Ph. D.
he
RHIC UEC/Diversity Working Group
Brookhaven National Lab, sPHENIX Experiment
Associate Professor
Ohio University Dept. Of Physics and Astronomy
frantz AT ohio.edu
 646-228-2539

________________________________________
From: Frantz, Justin
Sent: Sunday, January 16, 2022 11:58 AM
To: sphenix-hcal-l AT lists.bnl.gov; sphenix-emcal-l AT lists.bnl.gov; sphenix-calibration-l AT lists.bnl.gov; sphenix-software-l AT lists.bnl.gov; sphenix-l AT lists.bnl.gov
Subject: Calorimeter Calibration mtgs :  alternating Wed's 1pm (this wk) & Thursdays 4pm.

Hi all,

As advertised at the collaboration mtg, we will be starting a new series of biweekly/weekly meetings for Calorimeter Calibrations.   The focus will be any calibrations-related calorimeter software, but we plan to also discuss any calorimeter calibrations developments such as the LED systems.   Megan Connors and I (Justin Frantz) will convene these meetings.   The purpose is to try to unify as much as possible the approaches for calorimeter calibrations and software for both the Hcals and the EMcal.    The polls indicated it was complicated to schedule to get everyone needed all together at one common time.    So we have decided on two different times that will alternate which allowed everyone of the many who filled the poll (thanks!) to attend at least one of the two times.

The "Main" meeting time will be biweekly held every other ***WEDNESDAY AT 1-3 pm (Eastern US time) ****   We will have the first of these meetings _THIS COMING WEEK_ (Wed. January 19, 2022)  Please plan on attending now, and let Megan and I know if you have anything  to present.   Agenda and zoom links/info will come in a separate email.

The 2nd mtg which will be called the "Technical"  meeting  (mainly just to differentiate it) will be held  *** THURSDAYS  4-5pm  (Eastern US time)**** also biweekly, but  in the alternating weeks when the "Main" meeting does not occur--thus the first meeting of this type will be next week 1/27/22.

Please mark your weekly calendars and hope to see everyone interested in calorimeter calibrations at these meetings!

-Justin


----------------------------------------------
Justin Frantz, Ph. D.  ,  he
RHIC UEC/Diversity Working Group
Brookhaven National Lab, sPHENIX Experiment
Associate Professor
Ohio University Dept. Of Physics and Astronomy
frantz AT ohio.edu
646-228-2539
PERSONAL ZOOM MEETI

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