Spent whole day trying to isolate mezzanines from cooling crate.

Finally managed to increase resistance between crate and mezzanines from ~5 Ohms to ~380 kOhms with some masking tape and parcel tape over the slots in the FEE modules in which rest the guide pins on the bottom of cooling crate.

See excellent performance in nnaida11, with peak widths down to ~45ch and almost perfectly smooth waveforms.

         - this is with just the kaptons connected (all of which are shielded with tape) and no detector. Shaping time of 8us.

Performance in other FEEs remains largely unchanged. (Note: Yesterday saw similar performance in nnaida13+14 for 15mins but lost it and couldn't regain same performance.)

Turned off cooler to see what effect that had - no major changes to peak widths.

Turned off cooler and loosened crate lid - again no appreciable difference.

=> It seems this electrical connection between cooling crate and mezzanines could be the source of a lot of our noise.

Could remove pins completely to see effect that has, before trying with plastic ones when they arrive.

Attachment 1 shows FADC monitor during period in which ADCs in nnaida14 were not calibrated correctly.