Bad Channel Lists

Bad channels come from a number of sources:
  • Broken wires that occurred during APA construction
  • Wires that neighbored the broken wires and were "jumpered" onto them
  • Isolated dead channels in the FEMB that were present before cooling down
  • Large groups of dead FEMB channels that occurred after cooling down. Typically these occurred in groups of at least 16

The current (January 3, 2017) Bad Channel List (using online numbering) is in:

It has 258 bad channels listed.

It was compiled by Michelle Stancari and Alex Booth based on looking at the event display for about four runs.

They found 166/896 dead collection wires and 102/1152 dead induction wires. 10 of these were later removed from the bad channel list.

The documentation for this is in the talk from May 4, 2016:

and in DocDB 2047

Ryan Linehan did a check of the run dependence of the bad collection wires. He looked at hit occupancy in a series of runs. He considers channels in the peak of the occupancy gaussian to be good and those at too low or too high values to be bad. He finds a somewhat higher number of bad collection channels (~200) - probably due to the ones with "too many hits". But, overall, the number of bad channels did not vary much from run-to-run in periods when the electronics status was constant. The documentation for this is the his talk from June 15, 2016