We re-installed the "new gated grid drivers (with fixes)" to see if we could see any of the issues we saw during the Cosmic run in February.

I put a bunch of plots below.   I have several points in summary:

1.  We don't see a gated grid peak at all in the iTPC adc data in normal zero-suppressed runs.   I think this must be removed by tonko's code.   The baseline
     for the tpc in february was very nearly perfectly quiet in both the itpc and the tpx.

2.  We are seeing the gated grid issue ALL THE TIME now.

3.  We still see metastable shifts where the size of the problem becomes much larger for a while.   These shifts appear to have the same shape as the 
     the previous shifts, but they have a much larger amplitude.

-Jeff

Here are the number of pixels hit in the itpc/tpx during a cosmic run in april, where we can see the issue:

 
The jumps in size are the points where the problem exists.

Here is the results from a current run:

We clearly see similar jumps.  However, notice that the baseline sizes (measured in pixels hit) are much higher.   In the itpc the values are close to the "Bad regions" of the February run.   The tpx also always shows noise, but to a lesser degree.     When the jumps hit, the problem gets worse by a large factor!

Initially I thought that the difference was due to noise from channels that are typically masked out, however, when I looked into the data, it is pretty clear that we are seeing the same thing as we did before:

Here is are 3 event display images from February during one particular run.   Notice that in the first ("good") events, the TPC is completely quiet.  During the first period of problems one side of the TPC shows a sheet near the endcap, During the second period of problems the TPC shows a sheet near the other endcap.

Here are the same plots images for the "good" and "bad" regions during september!   Notice that the "good" regions, are very like the "bad" regions in February:

When I look a the profiles (The summed number of pixels hit for each time bin in a single event) we see (in the worst 3 sectors)

and

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