May 7, 2014 Calibration

Connection Using Bluejeans

To join via Polycom room system go to the IP Address: 199.48.152.152 (bjn.vc) and enter the meeting ID: 630804895.
To join via a Web Browser, go to the page [1] https://bluejeans.com/630804895.
To join via phone, use one of the following numbers and the Conference ID: 630804895
- US or Canada: +1 408 740 7256 or
- US or Canada: +1 888 240 2560
More information on connecting to bluejeans is available.

Attending: Sean, Amiran (NU); Curtis, Naomi (CMU); Simon, Lubomir, Mark (JLab); Justin (MIT)

Collaboration Meeting May 12-14
- Sean will collect information about the measurements that each subdetector group is planning to make this year for the calibration discussion next Tuesday,
Status Update
- Sean has been working on applying constants to the digitized values. This has involved reviewing the constants needed and working through some lingering bugs with EVIO file reading/writing with David L.
Tracking
- Naomi reported on plans to correct the drift distance calculations for the variation of the magnetic field in the CDC.
  - In the CDC volume, the magnetic field varies from 1.3T to 1.9T at nominal current, primarily in z.
  - At large drift radius, she finds that the drift radius changes by a maximum ~30um per 0.1T, compared to a resolution of 80-100um.
  - To correct for this effect, the plan is to get a best guess for the r,z of the hit, guess the B field at that point, correct the drift time to what it would be in a 1.3T B field, then convert the time to distance using lookup tables. These corrections would be applied at the point of converting the digitized hit into a normal CDC hit.
  - With a "simple" parameterization of these effects, Naomi gets to within 2.5ns -> ~15um of the actual drift distance.
  - Sean suggested that we should have a discussion during one of the breaks in the Collaboration Meeting about how to integrate these (and other) effects into mcsmear.
- Simon has added in some constants to be used for dE/dx determination.