RC report for 8 April Swing through 9 April Day

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Log entry time 16:33:28 on April 09, 2004

Entry number 81878

keyword=RC report for 8 April Swing through 9 April Day

Run Coordinator's Report for 8 April Swing to 9 April Swing

Summary

LH2 production running. SMS fast dump at 2:00 AM, 5.5 hour recovery. More LH2 production running.

Significant News

IHWP now OUT.
Lumi 7 still not working properly. Still not clear what the cause is, but some ideas should be floated around, and next Monday's maintainance day would be a good opportunity to implement them.
DMCH Interface box is the "new" box, and 120 Hz mode still does not work for French electronics. A new procedure for 120 Hz running will be to set acquisition mode to TS_Scaler rather than TS2_full.
Analysis and worker shift personnel seeing many crashes in cdaql1. Paul has requested that these positions generate a shiftly log of how oftern and when these crashes occur. These do not have to be log entries the moment the crash occurs, but at the end of your shift, make one log entry which summarizes the crashes.
A Damon analysis for all of the data since the change to 4 pass running shows that the BCM monitors in the hall are showing charge asymmetries that are not zero at about the 3 sigma level. We should resurrect the Injector DAQ and measure the charge asymmetries there during the same time as we are running in the hall to see if the same effect is present in the injector, or these are caused by some differential scraping down stream of the injector entrance to the accelerator. (Volunteers?) However, due to the Hall A turn on, if Hall A beam is being delivered, the charge asymmetry in the injector is a combination of both Hall A and Hall C charge asymmetries. This may only be useful for us if Hall A has no beam being delivered to them.
We will be down for all day Monday, and through Day shift on Tuesday. This means that worker and leader shifts will not need to be manned from 8:00 Monday through 16:00 Tuesday. We will need one target expert on Monday morning to boil away the target and put it in a safe state at 30 K. When to fill the target again (either Tuesday Swing or Wednesday morning) will be determined by the promise of beam and when we can expect it back in the hall. This decision will be made Tuesday afternoon. We will also need a SMS expert on Monday morning to ramp down the magnet and put it in a safe state for the shutdown.

Plans

During beam down time tonight due to MCC beam studies (getting the Hall A tune better), we will perform some special DNL runs, some with the GMS on and some with the GMS off.

Continue with LH2 production running until Saturday morning.

Run Moller/IHWP insertion/Moller Saturday morning at 8:00.

After Moller measurements, BUT BEFORE PUTTING THE LH2 TARGET BACK IN, we want to run some short test runs to investigate various things.

1) A 1 hour run with detectors and SMS on, but LH2 target out (effectively a "green block" run, with the YO signal in the data stream, checking for helicity correlated YO effects).

- if no signals are present in the detectors, we may have to go to the HIGH GAIN HV settings to mimic the "green block" runs.

2) The Halo monitors are showing some strange behavior, in that they measure a relatively large asymmetry (~50 ppm) in one helicity state but not the other. We would like to address the impact of this on what the FPD's are seeing. Mark and Sarah have outlined a program to investigate this, and some of this can be performed with the LH2 target out in combination with the DNL runs discussed in 1). We will make measuerments with the 6 mm halo target in and out, and one with the 5 mm small hole target on the LH2 target ladder in with the 6 mm halo target out. This will constrain the contribution of the halo asymmetry to the asymmetries measured in the FPD's during normal LH2 running.

Continue with LH2 production running until Monday at 7:00 when the maintenance period begins.

We are now on our official 3 day cycle for Moller measurements/IHWP state changes.

Concerns

Spikes in French electronics
Non-statistical widths in detectors 13 and 14 of octants 4 and 8.
Non-understood influence of Interface Box to DMCH's. Spare does not work in 120 Hz mode.
NA LTD errors still occurring at a smaller rate. Brian has generated a "HowTo" document (located on the G0 web page under http://g0web.jlab.org/manual/Electronics_manuals.html) for trouble shooting.
Crosstalk with target IOC and target FSD box when the Musson box is rebooted remotely
Changed behavior of BPM 3H00C Y position with respect to other hall BPMs.
Lumi 7 issues.
cdaql1 also crashing at a pretty regular rate.