25/02/15
1200: Swapped out old green power switch for new one from UoE (having previously tested them both yesterday and found them to work fine).
With first switch connected and PuTTY session opened cannot get RPi to connect to it. See (bodged) screen shots below.
Tried many permutations of trying to connect using ttyUSB0/1/2 with various permissions set, none yielded any results other than the error messages below.
1500: Swapped 1st UoE power switch out for the second. Plugged it straight in and it works... ???
Later unplugged it and when reconnected saw the same errors as before. We got rid of these by plugging in the USB cable once the unit was powered on. Does this make any sense, or was it just luck?
Carried out pulser walkthrough to file R22_0. Use same "best" settings as yesterday.
Changed polarity of detector bias (from -100V to +100) and observed a similar leakage current as previously (11.5uA) and normal rates/spectra for each detector. No obvious changes from -ve bias polarity. GOOD.
1830: Looked at effect of supplying each FEE64 from various power supplies (as per request PC-S email on Sun 22nd Feb).
Original configuration : | 1 2 | 4 3 | 5 7 | 8 6 | (all in one PSU)
Changed to: | 1 - | - - | - - | - - | PSU#1
| 3 - | - - | - - | - - | PSU#2
| 6 - | - - | - - | - - | PSU#3
| 8 - | - - | - - | - - | PSU#4
with PSUs #3+4 completely unplugged apart from nnaida6+8. In PSUs #1+2, the remainder of the slots were connected as previously (apart from for nnaida3,6,8, in which case they were swapped for another FEE64 at random).
Initially all PSUs were plugged into one half of the power switch, but the fuse blew. We replaced it with a spare fuse from the unused supply and distributed the PSUs 2 to each half of the switch.
This configuration yielded larger FWHM than original set up ---> worsened performance.
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