2017-09-20 scifi dead channels¶

See plots_9621.tar.gz There are a bunch of plots with names like:

tkd_sp_1_x_tkd_sp_1_y_all_triplet.png

This means I am plotting:

• "x" in tkd space point 1 vs "y" in tkd space point 1
• all events
• triplet space points only

The code for the "triplet" bit of the name is:

• triplet - all triplet space points
• doublet - all doublet space points
• any_sp - all space points
• triplet_used - all triplet space points with "used" flag set to true (I think this means PR used the space point)
• doublet_used - all doublet space points with "used" flag set to true (I think this means PR used the space point)
• all_used - all space points with "used" flag set to true (I think this means PR used the space point)

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I draw your attention to the following plots, which show completely inactive regions (they are plots for all space points, triplet and doublet combined)

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I also note

show an interesting asymmetric distribution. It is not apparent in the corresponding "any_sp" plots.

• It might result from some of the beam hitting the walls here (these are most upstream planes of tku).
• It might result from selection bias; because I only plotted "used" tracks, only those events that could make a good track are shown; and these all sit to one side of the detector in TKU st 4 and st 5. There is not such a big dead region that I would expect to see something like this, however.

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Please also note the chi2 plots:

• Black is all events
• Red is all events within a TOF01 cut with track in TKU
• Green is all events within a TOF01 cut with track in TKU and TKD

show decent chi2 for the tku and tkd tracks which are found.