[Halld] Commissioning Update

[David Lawrence]

Dear Collaborators,

 The accelerator was able to deliver good beam to Hall-D again over much of the weekend. In
some ways too good. We were able to take data in mode 8 (full waveform samples) at 600MB/s.
This exceeds our design goal of 300MB/s. For some periods we were writing to disk faster than
we could send data to the tape library (empirically limited to a measly 450MB/s). A nice stress
test of the system! This was made possible by some progress on the DAQ system last week that
allowed us to run at a higher event rate. We now have several TB of new data and have doubled
the data volume obtained from the entire history of the GlueX detector in just 2.5 days!

Here’s a summary of the weekend accomplishments:

- Good beam for much of the weekend.
- Tagger threshold scan (TAGM and TAGH)
- TAGH voltages adjusted
- Latencies adjusted for individual systems (TOF,  ST)
- Trigger/DAQ development
   + 1.5 - 2kHz trigger rates
   + (FCAL+BCAL)*ST trigger
   + 600MB/s data rate (slight back up going to tape)
- PS + Tagger data (multiple conditions)
- High intensity beam tests (higher current, thicker radiator)

As a reminder, the accelerator will be shutting down on the morning of Dec. 22nd. We won’t see 
beam again in the hall until the “Physics Commissioning” run in the Spring. We will need to discuss
how to best use our last week of beam during the 8:45 RC meeting this morning.

Also, remember that Alexandre Deur will be taking back the reins as Run Coordinator today and I’ll
take over for him again on Friday.

Regards,
-David Lawrence