[Halld] Commissioning update

[David Lawrence]

Dear GlueX Collaborators and friends,

  We had some significant success yesterday in aligning the first diamond (see 
the e-log entry here: https://logbooks.jlab.org/entry/3335562). We are able to 
see and move the coherent peak in both the Tagger hodoscope and Pair Spectrometer.
(Yes, they were correlated.)

We ran for then ran for several hours overnight with the diamond radiator set to
align the coherent peak at 3.4GeV. There may be some issues with this data and
analysis of it is ongoing.

Today has been less successful. A vacuum leak in the injector caused them to take
away beam first thing this morning. It came back around noon, but with significant 
tails that took them all afternoon to beat down. Just as the beam was starting to
look usable, they took it away again in order to tune Hall-B. We are now expecting
beam any moment and with some luck, get rolling with the day’s program of
aligning a second diamond and optimizing the PS trigger/DAQ.

We have scheduled a FastFeedback (FFB) system study for tomorrow morning
starting at 9am which should take 2-3 hours. This will be done by the accelerator.


Alexandre will return tomorrow to resume duties as Run Coordinator.

-David Lawrence
Acting Run Coordinator