Hi,
we are running with ABS D2 again since 1pm.
The new SFT Hall probe does not work properly, some irreproduceable
problem with the wiring of the new probe is suspected.
We are now running based on current reading only. This has the danger that
the field may drift away and we would lose SFT/WFT transitions.
So far, ABS has been running for three hours without failure. We keep
running like this over the weekend. If things remain stable, we may
eventually just run on. If we face the mentioned instability, we will
probably need another three days break next week to install yet another
hall probe.
People on shift should look at the yellow top compression tube for states
1-3 and the orange bottom compression tube ligit signals to tell if the
SFT/WFT unit works (in the "newRFT.adl" EPICS window in the top-right
corner).
In case of a full SFT/WFT failure (with all SFT/WFT transitions affected),
the orange states 4-6 ligit would show very little -positive- spikes. In
normal operation, the spike during change of spin states would be
negative and sizable.
In case of only one failing SFT/WFT transition, the level of the yellow or
orange ligit gauge would be persistingly changed.
Run plan:
If ABS SFT/WFT fails before Sunday night, we will switch to unpolarized
deuterium and run (with ABS software running!) until Sunday night 12am, at
which time we would switch to empty and start warming up to prepare for
Monday's repair.
If the ABS runs without failure, we continue to run polarized deuterium
until Monday morning when the cards are reshuffled.
Please keep pol.log and RUNLIST-D2.4 up to date and monitor the
polarizations.
Regards,
Michael
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