DIRC Operations Report
Wednesday 2008/01/09 to Wednesday 2008/01/16
Oncall: Jose Benitez (Joe Schwiening and Jennifer Prendki on backup)
Fast Monitoring: Joe Schwiening, Jose Benitez, Jennifer Prendki
Luminosities this week
PEP peak lumi: ~9.9 x 1033
(last week: 8.3 x 1033)
PEP delivery: 2.2 fb-1
BaBar integrated lumi:2.9 fb-1
Run 7 total delivery: 10.55 fb-1
Run 7 total BaBar recorded: 10.44 fb-1 total,
including 0 fb-1 off-peak data and including 9.82
fb-1 on the Y(3S)
PEP activities/issues this week
There was a ROD on Wednesday and Thursday because PEP needed
to replace a kicker magnet on the HER.
"BOAT_LER" system broke in the swing shift. Caused some down time.
BaBar activities/issues this week
Many subsystems used the ROD on Wednesday and Thursday to
make minor repairs.
Usually smooth data taking.
DIRC activities/issues this week
During the ROD on Jan 9: There was a new flow sensor
installed on the chiller. This appears to be working fine, no
Also, Matt,Jerry and Jose made a controlled access to the top
of the detector to investigate the flaky Nitrogen flow meter
electronics. No problem was found. The electronics were just
cleaned. The instabilities have not returned.
One channel was masked because it became noisy. Sector 0, DFB
5, channel 2.
On Thursday evening there was an automatic page due to the
circulation pump on the water plant. This was found to be due to
a glitch on the building power.
Friday we started to see bad timing distributions on the Fast
Mon Plots. There were 3 periods where the distributions were so
bad that the signal peak was not visible. This bad distributions
appeared even though the scalers and other subsystems were OK on backgrounds. This has now been found to be due to bad trickle
injection on the LER. This problem has persisted.
One HV channel in Sector 2 tripped and was ramped back
up shortly after. The trip appears to be due to bad backgrounds,
the channel looks healthy.
See DIRC logbook for details
Lumi and Background this week
- Investigate further the problem with the distorted timing
- Joe, Jose and Jennifer rotating oncall and backup duties.