Log entry time 23:39:31 on February 26, 2004

Entry number 77953

• Data taking on LH2 target with 40 uA with 6 mm hole target and beam positioning study.
  
• IHWP is now in (changed on Wednesday 02/25)
• LH2 target parity quality
• 16.2 hours for this 2-day period (runs 20171-20259)
• Overall efficiency: 33.8% (16.2/48)
  
• Beam (no trip) efficiency: 83% (19.3/23.3)
  
• Parity efficiency: 84% (16.2/19.3)
• Total parity hours: 136.6 (runs 19815-20259)
• Overall IN/OUT charge ratio: 0.827
  

• Production running during the swing and owl shifts at 40 uA and running with 6 mm halo target.
• Moller measurement of beam polarization (Log Book Link) before and after IHWP change to IN.
  
• RIP scans after Moller (Log Book Link) and after beam studies involving Wien filter (Log Book Link).
• BCM/BPM calibrations performed (Log Book Link).
• Lumi calibration performed using "frame" target (Log Book Link).
• 120 Hz data taken during Owl Shift and Swing Shift of 02/25 and during Owl Shift of 02/26.
  
• Coil modulation data taken during the Owl shift (Log Book Link and Log Book Link) and Swing Shift (Log Book Link) of 02/25 and during the Owl Shift (Log Book Link) and Day Shift (Log Book Link and Log Book Link) of 02/26.
  
• G0Integrity results recorded during the Owl Shift (Log Book Link) and Day Shift (Log Book Link) of 02/25 and during the Owl Shift (Log Book Link) and Day Shift (Log Book Link) of 02/26.
  
• Integrated helicity correlated differences were checked during the Day Shift of 02/26.
• A number of accelerator "beam studies" test plans were carried out on 02/26 during the Day Shift.  This was accompanied by a rather long (7- hour) with no beam in the hall during which,
• A cavity monitor attenuator was changed (Log Book Link)
• The SMS vacuum pumps were checked.
• French and North American DNL was measured
• The Moller target interlock switch was checked (Log Book Link).
• A no-beam test run of the GMS was performed (Log Book Link).
• The crate used to house IOCSE20 (associated with our BPMs) was evaluated for an orientation change, which some believe might reduce radiation damage crashes.  It turns out that this change would be difficult.
  
• The run coordinator took a nap.
  

• The rather large "Other" region on February 17, was mostly associated with 5.5 hr of high voltage calibration.
• The large "Other" band on February 18, includes time spent on harp scans (one hour) and BCM/BPM calibrations (3 hurs).
• The "Other" on February 24 was associated with  a long study of beam positioning. By agreement with the PD, we split the time for this study with the accelerator (1/2 of the time was counted as Beam Not Available, 1/2 of the time was counted as Available Beam in Use).
  
• On February 25, the BCM/BPM calibrations were re-measured and the Lumi response to the "frame" target was measured as a function of current.

• Having spent about 9 hours (9 AM until  almost  6 PM) doing Beam studies, we would normally be "good to go" for a long period of production LH2 running.  However I have been informed that another period of down time must be folded into our schedule due to a vacuum leak in the accelerator.   According to MCC, this could be from 3 to 5 hours (starting at the beginning of the Day shift on Friday 02/27).  Past experience with vacuum problems suggests that this may be an underestimate.  But it is better to take care of it during the Day shift on Friday than the Owl shift on Saturday.
  
• We will stop at roughly 9:00 AM  every day for 1/2 hour to perform Chow's fOps test plan until further notice.
• The Moller measurement, followed by IHWP reversal (to IN), followed by another Moller measurement, and then a RIP scan that was normally scheduled for Friday will be postponed until Saturday (assuming the Moller team is amenable).  Due to the long period of beam studies, our own BCM/BPM and lumi calibration, and the unplaned down time tomorrow, we have not taken much parity data.
  
• When the beam returns on Friday, we will proceed with production LH2 running.  This will continue through the weekend with a brief interruptoin on Saturday for the Moller measurements and IHWA change.

• Laser phase noise problem can be monitored by making a StripTool plot of the EPICS variable for the phase noise next to the EPICS variable of the uncertainty in the charge asymmetry (produced by the charge feedback routine) which is proportional to the asymmetry distribution width (Log Book Link).  MCC has asked for some kind of real time display of our charge asymmetry width -- I think this would sufice.

• There has been a slow trend toward lower elastic proton rates also seen on both detector packages.  No good explanation yet.

• Spikes in the French timing spectra appear from time to time (Log Book Link).  Louis is now here.  Perhaps he can make some headway in the diagnosis of this problem.

•  The North American electronics has had errors again (Log Book Link).  We have had no particular insights on the resolution of this problem.

• The idea that the beam is more difficult to position at 40 uA CW than at pulsed 20 uA was corroborated by Mike Epps (MCC operations). We need to test the current dependence of our BPMs.  I believe that a quick check could be done by examining the deviations from linearity of the measurements of our 4 BPMs as a function of current in the situation that the "auto gain" feature of the BPM electronics is enabled.  Another possibility is that the BPMs behave differently with and without the raster.  This could be quickly checked by setting up in the conditions where we can withstand the highest unrastered beam current, measuring the position, then switching on the raster changing nothing else and re-measuring the beam position.

• We continue to have problems with the AC in the electronics cage (Log Book Link).  Also, as a result of changes to the system the temperature has dropped by about 6 degrees C.  This can effect the electronics in unexpected ways.  The DNL has now been re-measured at the lower temperature, but we need to consider  re-optimizing the other parameters of the French system.

• One run (20246) showed a large reduction in rates on both French and North American detectors.  Paul traced this to a brief shift in the Musson box timing shift by about 0.5 ns.  It is not clear what caused the change in timing.
  

• MCC and the ABU accountants have asked that we justify more clearly our decision to count the 70 sec after a trip recovery as Beam Not Available.  This criterion was determined based on data from the first engineering run and is explained in a report by Silviu 
  

Tuesday 02/24 Swing and ABUs
Wednesday 02/25 Owl and  ABUs
Wednesday 02/25 Day and ABUs
Wednesday 02/25 Swing and ABUs
Thursday 02/26 Owl and  ABUs
Thursday 02/26 Day and ABUs