sPHENIX cold QCD topical group

[Alexander Bazilevsky <shura AT bnl.gov>]

I support Jin's configuration.

Sasha.

On 2/5/19 10:28 AM, Lajoie, John G [PHYSA] wrote:

Hey Jin,

 

Very nice. We were trying to have only *two* types of light guides to simply manufacturing, but that yielded the central 7x7 fiber tower that Sasha was unhappy with, and in any case I don’t think it add too much to the cost or complexity to have three light guide styles. What I do like about this very much is that it keeps the assembly module-based, in that we are always dealing with 10cm x 10cm “supermodules” instead of trying to assemble across physical E864 towers.

 

As Sasha showed in his simulation results, averaging over towers that differ by one fiber cell in the horizontal or vertical dimension doesn’t seem to hurt you too much when you use the shower shape, so this method would likely work similarly (even though the towers are a little larger).  In the long run, if we really did this, I suspect you would probably not want to average, especially in the eta 3-4 region, but actually deal with the complexity of the varying tower size. It’s possible the variation is all swamped by shower fluctuations, but simulations should show this.

 

So, while I think this is much better than what I showed at the meeting last night, it still implies a trade-off – we accept a varying tower size to simplify construction at the expense of complicating the analysis, or we complicate construction to keep a uniform tower size.

 

IMHO my preference would be to implement the 3-style array in simulation and for the test beam this year.  That gets us going, and gives us time to use simulations to answer the question of just how big a problem a variable tower really is, or if we can develop ways to optimize.   If we go forward with funding for the full fEMC in the future we might revisit this and reconsider a uniform tower size, but we would have some engineering resources at that point to better tackle the problem and it wouldn’t be much of an extrapolation from what we have tested.

 

Thoughts?  If this seems OK I can modify the simulations and pass this on to Dan to do some ray tracing and make drawings for the light guides.

 

John

 

 

From: Huang, Jin <jhuang AT bnl.gov>
Sent: Monday, February 4, 2019 10:02 PM
To: Lajoie, John G [PHYSA] <lajoie AT iastate.edu>
Cc: Aidala, Christine <caidala AT bnl.gov>; 'sphenix-cold-qcd-l AT lists.bnl.gov' <sphenix-cold-qcd-l AT lists.bnl.gov>
Subject: RE: [Sphenix-cold-qcd-l] Next Cold QCD TG meeting Mon, Feb 4, at 8:30 pm EST

 

Hi, John

 

Thanks for pushing this idea forward. Attached is the 3-type 5x5-matrix lightguide layout I mentioned in the end of the meeting that could fit a 47x47-fiber E864 module.

 

Cheers

 

Jin

 

 

______________________________

 

Jin HUANG

 

Associate Physicist

Brookhaven National Laboratory

Physics Department, Bldg 510 C

Upton, NY 11973-5000

 

Office: 631-344-5898

Cell:   757-604-9946

______________________________

 

From: sPHENIX-cold-QCD-l <sphenix-cold-qcd-l-bounces AT lists.bnl.gov> On Behalf Of Aidala, Christine
Sent: Sunday, February 3, 2019 10:01 PM
To: 'sphenix-cold-qcd-l AT lists.bnl.gov' <sphenix-cold-qcd-l AT lists.bnl.gov>
Subject: Re: [Sphenix-cold-qcd-l] Next Cold QCD TG meeting Mon, Feb 4, at 8:30 pm EST

 

Dear all,

 

This is just a reminder of our Cold QCD TG meeting tomorrow (Monday, Feb 4) at 8:30 pm EST.

 

Christine

 

From: Aidala, Christine
Sent: Saturday, January 26, 2019 9:30 AM
To: sphenix-cold-qcd-l AT lists.bnl.gov
Subject: Next Cold QCD TG meeting Mon, Feb 4, at 8:30 pm EST

 

Dear Cold QCD enthusiasts,

 

We will have a meeting on Monday, February 4^th, 8:30 pm EST to discuss efforts by John Lajoie, Sasha Bazilevsky, and Joe Osborn towards a forward EMCal based on the E864 calorimeter sections.

 

The meeting is BlueJeans only (https://bluejeans.com/345777492) with two talks on the agenda so far https://indico.bnl.gov/event/5651/.

 

Overview of sPHENIX forward EMCal based on E864 calorimeter sections – John Lajoie

Simulation studies for forward EMCal based on E864 calorimeter – Sasha Bazilevsky

 

Let me know if you’d like to be added to the agenda.

 

Best regards,

Christine

 

--

Christine A. Aidala

Associate Professor

Department of Physics

University of Michigan

(734) 764-7611

 

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-- 
Alexander Bazilevsky
Brookhaven National Laboratory, Bldg. 510D, 2-232
Upton, NY 11973 Tel: 631-344-3712
Email: shura AT bnl.gov
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