sPHENIX tracking discussion

["Bertaux, Joseph Tyler" <jbertau AT purdue.edu>]

Hello,

The survey data hasn't been compiled; I see an approximate 5mm shift in "y" in the survey data, but I'm not sure if it's the actual "y" coordinate. It's the second in the list but the physical dimensions and values seems to be consistent with the z coordinate.

I've had to guess which coordinates are actually which, and I need to modify the mapping of our online/offline indexing conventions again after noticing the reference image I've been using is mirrored on the x axis.

I'll remedy this tonight and tomorrow.

What specific values are those plots for? Because if you're plotting the mean strip_x/strip_y, "strip_y" is actually along the z axis and this would make sense with what I'm seeing.

Whatever it turns out to be, I'm confident you can attribute this to the INTT's position and not the actual beam. My guess is the reconstruction is still using the default model, which would be close to nominal, while the survey shows a shift that hasn't been incorporated yet. Consequently you see the shift in the beam center.

Joseph

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From: Sphenix-intt-l <sphenix-intt-l-bounces AT lists.bnl.gov> on behalf of nouicer <rachid.nouicer AT bnl.gov>
Sent: Monday, July 17, 2023 7:38 PM
To: sphenix-tracking-l AT lists.bnl.gov <sphenix-tracking-l AT lists.bnl.gov>; sphenix-run-l AT lists.bnl.gov <sphenix-run-l AT lists.bnl.gov>; sphenix-intt-l AT lists.bnl.gov <sphenix-intt-l AT lists.bnl.gov>
Subject: [Sphenix-intt-l] Beam Spot and sPHENIX/INTT Geometry

 

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Dear Joseph and Tony,

Please see the attached plots which correspond to the RHIC beam spot in X, Y directions obtained by the INTT detector using beam data with magnet-OFF run =20869 taken on 08 July 2023.

We observe that the beam spot coordinates is (0 mm, 5 mm); this means the beam spot is shifted by five mm in Y direction.

Before Stefan shows this plot to CAD, we need to understand is this shift by five mm is due to the beam shift itself, or it is caused by the INTT detector geometry (not fully implemented in our software).

I already provided you with the INTT local survey data (obtained at the lab for each ladder) as well with INTT Global survey data (obtained at the sPHENIXPHENIX IR).  Are these survey data implemented in the present sPHENIX/INTT detector geometry that we are using in our analysis or not?

We would highly appreciated your feedback. 

Sincerely,
Rachid for the INTT Group

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                                                 /                     /
 Rachid Nouicer                                 /                     /
 Brookhaven National Laboratory                /                     /
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 Address:                                    /                     /
 Brookhaven National Laboratory (BNL)       /                     /
 Physics Department, Building 510c         /                     /
 20 Pennsylvania Avenue                   /                     /
 Upton, New York, 11973, U.S.A.          /Phone:+1 631 344 8433/
                                        /                     /
 E-mail : rachid.nouicer AT bnl.gov       / Fax:+1 631 344 3253 /
 Web:http://www4.rcf.bnl.gov/~nouicer /                     /
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