From GlueXWiki
Jump to: navigation, search

June 30, 2016 Drift Chamber meeting


  1. Instructions for Bluejeans meeting connection
  2. Meeting ID: 290664653

Headline text

  1. To join via a Web Browser, go to the page [1] https://bluejeans.com/290664653.


  1. Detector updates
  2. NIM Papers
  3. fADC125 meeting (Naomi, Cody, Beni)
  4. Other


Participants: Sean (NU),Curtis, Naomi, Mike (CMU) Luke, Alexander A., Simon, Sergey, and Lubomir (JLab).


- Naomi is working on the gain calibration, Mike on the straw deformation effects and corresponding errors.


- Alex continued his presentation (linked above) from the last meeting now showing the Y-residuals (along wire) as a function of the X-residuals (first plot), both measured w.r.t. avalanche (hit) position. Since the avalanche is always on the wire, the X-residuals represents the drift distance and the Y-residual the deflection of the drifting electron due to the magnetic field. The linear correlation (third plot) means that the deflection is simply proportional to the drift distance, with a slope also proportional to the magnetic field. Garfield simulations confirm this. The Y-residuals are about 200 microns (second plot).

- Alex also worked on the FDC timing both from fADC125s and TDCs(next two plots). The drift time offset calibration has to be done for each run, since it may move.

- Lubomir is working with the GENFIT tracking package to study the FDC performance in magnetic field. The package uses Kalman fitter but also combined with the Deterministic Annealing Filter (DAF) that assigns weights to the hits and thus can solve left/right ambiguity. The package is using the Event Viewer Environment (Eve) for ROOT that offers good control over the fitting track by track (see pictures attached above). Lubomir is working so far with straight tracks but will continue with curved ones.


- There was a meeting (see link) with the detector group (Drew Weisenberger and Brian Cross) for building a TRD prototype. The plan is to build a chamber similar to the spare FDC package used for the TRD prototyping but with only 24x12 cm active area. The main difference is that we will apply negative HV to the upstream cathode that will be made out of thin aluminized Kapton.