Difference between revisions of "Minutes-9-10-2015"

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#* CDC response to 55Fe and 90Sr sources [https://logbooks.jlab.org/entry/3350888 logbook entry]
 
#* CDC response to 55Fe and 90Sr sources [https://logbooks.jlab.org/entry/3350888 logbook entry]
 
#* Electronics response [http://www.jlab.org/Hall-D/detector/fdc/55Festudies/Ion_tail_cancelation.png functions]
 
#* Electronics response [http://www.jlab.org/Hall-D/detector/fdc/55Festudies/Ion_tail_cancelation.png functions]
 +
#* The sag saga:  [https://logbooks.jlab.org/entry/3350978 maximum docas at center of CDC]
 
# FDC update  
 
# FDC update  
#* studies with 55Fe on spare package: [http://www.jlab.org/Hall-D/detector/fdc/55Festudies/5Fe_thick_9010_maxvstot_comp.pdf]
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#* studies with 90Sr and 55Fe on spare package: [http://www.jlab.org/Hall-D/detector/fdc/55Festudies/tek00009.png],[http://www.jlab.org/Hall-D/detector/fdc/55Festudies/5Fe_thick_9010_maxvstot_comp.pdf], [http://www.jlab.org/Hall-D/detector/fdc/55Festudies/5Fe_thick_9010_4060comp_maxvstot.pdf]
 
# Electronics
 
# Electronics
 
# Engineering
 
# Engineering
 
# Other
 
# Other
 
<!--
 
  
 
= Minutes =
 
= Minutes =
  
Participants: Curtis, Naomi (CMU), Fernando, Eugene, Luke, Beni, Dave, Marc (Mcmullen), Chris, Nick, Simon, Sergey and Lubomir (JLab).
+
Participants: Curtis, Naomi (CMU), Sean (NU), Fernando, Eugene, Luke, Beni, Dave, Marc (Mcmullen), Nick, Simon, Sergey and Lubomir (JLab).
 +
 
 +
== Other ==
 +
 
 +
- Curtis and Naomi discussed the tracking session for the coming collaboration meeting. So far two reports were requested, FDC (Lubomir) and tracking (Simon) update; expect one more about the CDC, to be discussed later. 
  
 
== CDC update ==
 
== CDC update ==
  
- Simon went trough half of the CDC layers: the deformations are not always in vertical direction, i.e. this may not be sagging. Need to make a map of all the measurements to make some conclusion.  
+
- Simon showed a map of the CDC (attached above) with the maximum drift distances, as seen by tracks coming from the target. Shown is the distance at the middle of the straw assuming sagging. One can see that certainly not all offsets can be related to gravity, so most likely there are tube deformations. Discussions how to parametrize the deformation and the time-to-distance function: most likely it is enough to use one function/table with extended distances (Curtis). Suggestions: to look along z, also to plot the asymmetry and sum in positive/negative phi.
  
- Beni: CDC is working now with the new MFC (separated from the FDC) blending the same 50/50 mixture. Need to verify this with the CO2 sensor.
+
- Scope pictures of signals from 55Fe source on one CDC straw shown the logbook link. When using adapter card without termination we saw ~20% reflection at 200 ns from the cable (18m). The reflections disappear when we used a terminated adapter card. However, it means that there's reflection not only at the adapter side of the cable but also at the HVB side - Fernando will look into that.    
 
+
- Measurements over weekend in mode 7.
+
  
 
== FDC update ==
 
== FDC update ==
  
- Lubomir showed cathode resolution results from the spring run with two different ST+FCAL triggers: run 3137 "standard" trigger and run 3200 excluding 4 additional layers of blocks in the center. The resolutions with the inner blocks excluded looks better and now very close to the one (~200 microns) in the fall run. This was achieved by using tighter cuts on the tracks used for the resolution studies; obviously the fact that we had half the energy in the spring explains this. Still, the offsets used for the fall and the spring runs are different and we don't understand why.
+
- Scope picture of the drift times in the two thick chambers of the spare package shown above, using 90Sr source and a trigger made on the scope by coincidence of two parallel wires from the two chambers. The max drift times for the first cell is about 9 usec, while Garfield predicts ~6 usec. The next two plots show the total charge vs max amplitude with 55Fe source: it demonstrates that with 90/10 gas mixture one can see the argon and escape peaks, also for big drift times they are broader (in time) possibly due to diffusion.
 
+
- Studies with 55Fe on the thick cell in the spare package: due to diffusion not all the charge is visible depending how far the photon interaction was from the wire. Expecting better results with 90/10 gas mixture where the drift times are much shorter. 
+
 
+
== Electronics ==
+
 
+
- The reason for the LV module failure not known yet.
+
 
+
== Engineering ==
+
 
+
- Dave is planing to shut down the interlock systems on FDC and CDC whenever that is convenient.
+
 
+
-->
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Latest revision as of 12:33, 17 September 2015

September 10, 2015 Drift Chamber meeting

Connection

  1. Instructions for Bluejeans meeting connection
  2. Meeting ID: 290664653
  3. To join via a Web Browser, go to the page [1] https://bluejeans.com/290664653.

Agenda

  1. CDC update
  2. FDC update
    • studies with 90Sr and 55Fe on spare package: [2],[3], [4]
  3. Electronics
  4. Engineering
  5. Other

Minutes

Participants: Curtis, Naomi (CMU), Sean (NU), Fernando, Eugene, Luke, Beni, Dave, Marc (Mcmullen), Nick, Simon, Sergey and Lubomir (JLab).

Other

- Curtis and Naomi discussed the tracking session for the coming collaboration meeting. So far two reports were requested, FDC (Lubomir) and tracking (Simon) update; expect one more about the CDC, to be discussed later.

CDC update

- Simon showed a map of the CDC (attached above) with the maximum drift distances, as seen by tracks coming from the target. Shown is the distance at the middle of the straw assuming sagging. One can see that certainly not all offsets can be related to gravity, so most likely there are tube deformations. Discussions how to parametrize the deformation and the time-to-distance function: most likely it is enough to use one function/table with extended distances (Curtis). Suggestions: to look along z, also to plot the asymmetry and sum in positive/negative phi.

- Scope pictures of signals from 55Fe source on one CDC straw shown the logbook link. When using adapter card without termination we saw ~20% reflection at 200 ns from the cable (18m). The reflections disappear when we used a terminated adapter card. However, it means that there's reflection not only at the adapter side of the cable but also at the HVB side - Fernando will look into that.

FDC update

- Scope picture of the drift times in the two thick chambers of the spare package shown above, using 90Sr source and a trigger made on the scope by coincidence of two parallel wires from the two chambers. The max drift times for the first cell is about 9 usec, while Garfield predicts ~6 usec. The next two plots show the total charge vs max amplitude with 55Fe source: it demonstrates that with 90/10 gas mixture one can see the argon and escape peaks, also for big drift times they are broader (in time) possibly due to diffusion.