Sphenix-calibration-l mailing list

[Ross Corliss <ross.corliss AT stonybrook.edu>]

Hi Tony,

To make sure I understand:  Assuming we have at our disposal a known-exactly-correct map of the static distortions, in a world unbounded by computation cost, each TPC hit is actually a path through the TPC, giving (xyz) as a function of (t).  

In the real world, we must make a preliminary estimate of the z position of a particle in order to correct its xyz position, since we can't hand a tracker the curved drift trajectories.   

The largest distortions will occur near z=zmax, since that's where the magnetic field diverges, so it is probably reasonable to make a crude assumption about the primary vertex z (or does the TPC track seed z mean something else?).  I will need to think more on how to measure the effect of this assumption, but I think it's doable with the data we have.

-Ross

==========
Dr. Ross Corliss

If it's work hours, and I'm not in a meeting, feel free to look for me in my virtual office:
https://stonybrook.zoom.us/my/rossoffice?pwd=ZmZ2SlRIMVFvUUJwbUkyOVNVTmE5QT09

On Oct 25, 2021, at 11:18 PM, Anthony Frawley via sPHENIX-calibration-l <sphenix-calibration-l AT lists.bnl.gov> wrote:

Hello Ross,

It would be useful to have a discussion about how precisely we need to know the z position of a TPC cluster to make a decent preliminary static distortion correction. This is prompted by starting to think about how to handle streamed data containing many bunch crossings, where we do not know the z position at all. 

Can we make a useful preliminary​ static distortion correction by arbitrarily moving the TPC track seed to z=0, which gets us within +/- 10 cm worst case?

Tony

---

From: sPHENIX-calibration-l <sphenix-calibration-l-bounces AT lists.bnl.gov> on behalf of Ross Corliss via sPHENIX-calibration-l <sphenix-calibration-l AT lists.bnl.gov>
Sent: Monday, October 25, 2021 10:41 PM
To: sphenix calibrations <sphenix-calibration-l AT lists.bnl.gov>
Subject: [Sphenix-calibration-l] TPC Distortions meeting, Tuesday, 11AM Eastern

 

Dear Distortions Folks,

A reminder that the distortion meeting will take place tomorrow at the usual coordinates and time, 11AM EDT.  If you let me know in advance, I will add a slot to the agenda for you, but impromptu updates are also welcome.

https://stonybrook.zoom.us/j/94081538941?pwd=Y256N3ptUC9zV2M4cjNtUGgyWnJYdz09

https://indico.bnl.gov/event/12844/

-Ross

==========
Dr. Ross Corliss
Research Assistant Professor
Center for Frontiers in Nuclear Science
Stony Brook University
ross.corliss AT stonybrook.edu

_______________________________________________
sPHENIX-calibration-l mailing list
sPHENIX-calibration-l AT lists.bnl.gov
https://lists.bnl.gov/mailman/listinfo/sphenix-calibration-l