[Halld-pid] Time-of-Flight Meeting Minutes, March 31, 2015

[Mark Ito]

PID'lers,

Find the minutes below and at

https://halldweb.jlab.org/wiki/index.php/GlueX_TOF_Meeting,_March_31,_2015#Minutes

   -- Mark
________________

GlueX TOF Meeting, March 31, 2015, Minutes

Present:

  * *FSU*: Brad Cannon, Paul Eugenio, Aristeidis Tsaris
  * *JLab*: Mark Ito (chair), Beni Zihlmann
  * *NU*: Sean Dobbs


Running at 6 GeV

We discussed implications for the TOF of running at lower energy.

  * At lower energy there will be more of the kaon spectrum in the range
    where the TOF is useful.
  * The pattern of rates near the beamline will be different. This will
    throw off any rate studies.
  * At lower energy using the FCAL for a trigger may be more difficult.
    The TOF can be used in coincidence to help.
  * For most of our other goals data with lower energy should not affect
    things. In particular, most calibrations can go forward.


TOF Matching with Charged Tracks

Sean showed some plots showing how well track matching is being 
performed for the Fall data. See his slides 
<https://halldweb.jlab.org/wiki/images/4/4b/TOF_Meeting_20150331.pdf> 
for details.
He showed a set of plots for each of two conditions, one set with the 
nominal 6 cm miss distance criterion and one set with the cut relaxed to 
20 cm. There is marked improvement with the wider cut, giving us 
confidence that better channel-to-channel time calibrations will improve 
the situation greatly.

Calibration

Beni and Simon Taylor are working on a quick-and-dirty calibration. Beni 
has passed constants to Simon and they are discussing how to incorporate 
them into the reconstruction.
Beni is seeing a systematic variation, from the inner paddles to the 
outer paddles, where uncalibrated times trend later on the outside, from 
5 to 10 ns. This is not understood at present.

Online Monitoring

Beni has checked in additional online monitoring plots. These will 
support his calibration scheme and as such may get us started with 
online TOF calibrations.

Retrieved from 
"https://halldweb.jlab.org/wiki/index.php?title=GlueX_TOF_Meeting,_March_31,_2015&oldid=65904"

  * This page was last modified on 1 April 2015, at 20:23.


-- Mark M. Ito, Jefferson Lab, marki at jlab.org, (757)269-5295
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://mailman.jlab.org/pipermail/halld-pid/attachments/20150401/071253c3/attachment-0002.html>