RC report Fall2021 w9
The production rate during this week was reduced as a result of several events, never-the-less we had >50% up time. On our side, the FDC chiller tripped due to overheating as a result of blocked chilled-water supply. The supply was restored by cleaning the needle valve and replacing the filter but the chiller was not functional. Later attempts to fix the chiller failed and we are running now without a spare. Another down time was caused by a power trip of the infiniband switch to which the whole Hall D computer cluster is connected. Restoring the computers took about 3 hours. Additional power (on a separate breaker) was added and the power on the computers was re-distributed, to avoid this from happening again. The accelerator was down for several hours due to flooding of the NL, another LCW problem causing the SL power to trip, pass changes that include now Hall A.
During this period the solenoid and the drift chambers were on. We started the week running at 200nA and full target. The weekend was event-less and we had very productive empty target running with about 90% up time. On Monday the target was filled (for about 3h) during the pass change and we continued taking data at 200nA. The full/empty target data was compared to the data from the previous weeks when the solenoid was off and the Primex people decided to continue with the solenoid on.
It was noticed that on Friday evening, during downtime, the tagger magnet was turned off then cycled and set to the nominal current, with the NMR probe showing minor shift of the field. This info was sent to the PD (later forwarded to the administrative leaders) asking for advice how to improve the communications with the Ops regarding the tagger. It turned out that the magnet was turned off following a new procedure that required this when accessing the NL. The magnet doesn't have to be turned off even when accessing the tagger hall. The procedure was corrected and the Ops were informed to contact us (with a notice on the magnet screen) in the rare cases when they need to change the settings of the tagger magnet.
