Revision as of 12:17, 24 September 2015

September 17, 2015 Drift Chamber meeting

Connection

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 == 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.
+- Simon showed new plots on the CDC tube deformation (elog linked). In addition to the last meeting results, now he has plots for positive/negative delta(phi) and most interestingly their sum and difference.
+The sum looks very uniform indicating that the
-- Scope pictures of signals from 55Fe source on one CDC straw shown in 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 ==