June 02, 2008 Tracking CDC/FDC

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Meeting Time and Place

Monday June 02, 2008 at 1:30pm At Jefferson Lab, the meeting will be held in room L207 (we believe)

Connections

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2.) Phone:

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then enter participant code: 39527048# (remember the "#")

Agenda

  • Announcements

Minutes

Present: Curtis Meyer and Yves VanHaarlem (CMU) Elton Smith, Jim Stewert, Mark Ito, David Lawrence, Simon Taylor and Dan Carmen.

Simon reported on a study that he had made looking at Pythia events, and plotting the energy loss in the FDC for all tracks (as a function of momentum). On average, the dynamic range of the ASIC is fine. However, there were questions about the small fraction of protons (perhaps from Hyperon decays) that might fall outside the shown curves. There was a question if you are biasing yourself away from these events if you are not careful.

Update (Simon): I have found issues with the plots I showed due to extra particle information in the PYTHIA simulated data that caused indices to be scrambled between the truth hits and the thrown tracks. The results after the bug fix are shown here:[1]

There was also a question on the material the Simon showed two weeks ago (the last meeting May. 19, 2008 Tracking CDC/FDC). Simon looked more carefully at this and when he shortened the integration window from 5 to 1 microsecond, things started to look a lot better (see the FDC Notebook).

Yves reported the first studies of the CDC using the Fe-55 source at CMU. This is still being investigated, so there are no conclusions yet. Hopefully we will be able to report additional information later this week. Yves also showed a plateau curve for the CDC that turns on at about 1750V. When combined with the counts in a time window, it appears that with 87/13 Ar Co2, the plateau goes from about 1750 up to about 1950 or 2000V. --> Indeed the threshold was set too high - updated spectra are in the wiki now (use the link above)


We also completed the study with the CDC tilted at 60 degrees, but the results are still being analyzed. More on this next week.

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