Whereas the single PS file containing all the plots is regenerated four times a day, the
individual files available here for the current data taking are only generated once a day
at 08.00.
The figures accessible individually below are available in single PS files
for 1996 , 1997 and
1998/9
The radial drift velocity is that determined in the reconstruction at L5 by using
tracks defined by the planar chambers. (But not for 1993!!)
The solid lines on these figures represent the calibration value in the database for each of the
quantities. The dashed lines are the plus/minus 1% bounds on the database value.
Drift Velocity & Tzero
It is important to maintain
accurate drift velocities and Tzeros for the Radial and Planar chambers as calibration
constants on the database to ensure the best reconstructed track parameters.
The history of the monitored values of these quantities together with the calibration
constants maintained on the database are available for:
For the 1997/8 plots the red points are normal ep data runs (minimal cuts), the green points
satisfy tighter cuts and are used for the calibration, the blue points are
runs at which a database update was triggered, whilst the yellow points
are cosmic and stable proton beam runs (these are very rare).
Mean Charge
Also available is the history of the mean charge of 'good clean' hits and the hit finding
efficiencies for both the Radial and Planar chambers:
and Efficiency
1996 Cosmic Runs
Two figures are available and give variation of drift velocity, twin peaks drift velocity, tzero
and mean charge with run number for planars and radials.
Maintained by gdp@hep.ph.liv.ac.uk
