Difference between revisions of "Meeting-1-25-2018"

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= FDC =
 
= FDC =
  
- Lubomir showed results from straight track runs. In total we had ~120M events, among them ~6M straight tracks with high quality. Alex B. will contact Mike Staib to see if that's enough for his
+
- Lubomir showed results from straight track runs. In total we had ~120M events, among them ~6M straight tracks with high quality. Alex B. will contact Mike Staib to see if that's enough for his Millipede alignment. We may ask for additional time at the end of the run if needed. The projection of the tracks on FCAL (plot at page 1) shows the exclusion of the inner FCAL blocks (4 on each side, making box 40x40 cm) visible on the plot. What is not understood are the four hot FCAL blocks inside that box, that were supposed to be excluded from the trigger.
 +
The wire residuals (page 3) will be compared with previous straight track runs in 2016.
 +
 
 +
- HV scan runs were analyzed by Lubomir using his straight track code limiting the analysis to small (<6deg) angles where the tracks are almost straight. The hit efficiency vs HV shows that with the nominal HV of 2225V we are well in the plateau (page 4). For the high intensity studies we should stay the DAQ limit and lower the HV till the current in the chamber is acceptable. As shown on the last plot, the loss of efficiency will not be significant.
 +
 
 +
- Alex A. also analyzed the scan runs with his plugin and showed that the loss of the efficiency for lower HV happens first at bigger drift distances (see plot attached).

Revision as of 19:04, 25 January 2018

January 25, 2018 Drift Chamber meeting

Connection

  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.

Agenda

  1. Status and current run analysis:
  2. Tracking
  3. fADC125
  4. Other


Minutes

Participants: Naomi (CMU) Eugene, Beni, Alex B., Simon, Sergey, Alex A., and Lubomir (JLab).

Status and current run analysis

CDC

- We discussed the settings for higher current running (up to 300nA) tomorrow (Fri 01/26/18). Eugene: we need the same conditions as for the normal running and if the chambers trip we will lower the beam current. Naomi proposed to lower the CDC HV of the inner HV sector (4 inner rings) from 2125 to 2025 so that they have current similar to the outer rings. Eugene wants to postpone this studies for later time when we have enough statistics and have dedicated studies of the DAQ rates and detector performance at higher fluxes.

- Naomi and Beni looked at the fADC thresholds - no need to be changed.

- Naomi has issues with her plugin for gain calibration. Using the same data and plugin now it gives different results: less hits in the outer layers, compared to earlier analysis in spring/summer of 2017. Simon will look into that.

FDC

- Lubomir showed results from straight track runs. In total we had ~120M events, among them ~6M straight tracks with high quality. Alex B. will contact Mike Staib to see if that's enough for his Millipede alignment. We may ask for additional time at the end of the run if needed. The projection of the tracks on FCAL (plot at page 1) shows the exclusion of the inner FCAL blocks (4 on each side, making box 40x40 cm) visible on the plot. What is not understood are the four hot FCAL blocks inside that box, that were supposed to be excluded from the trigger. The wire residuals (page 3) will be compared with previous straight track runs in 2016.

- HV scan runs were analyzed by Lubomir using his straight track code limiting the analysis to small (<6deg) angles where the tracks are almost straight. The hit efficiency vs HV shows that with the nominal HV of 2225V we are well in the plateau (page 4). For the high intensity studies we should stay the DAQ limit and lower the HV till the current in the chamber is acceptable. As shown on the last plot, the loss of efficiency will not be significant.

- Alex A. also analyzed the scan runs with his plugin and showed that the loss of the efficiency for lower HV happens first at bigger drift distances (see plot attached).