I am just learning how to do this "discussion forum" and putting this
note in the tracking, but it also holds for the whole detector.
Apologies if you already have this information. Mark Thomson and I
went throught the exercise at Daegu of answering the question of
how often we will need calibration runs at the Z pole. The answer needs a
guess at how often problems with the detector will occur that require
calibration data. To not just make a blind guess, we took the data from
Lep2 running, where this procedure (Z pole running for calibration) was
used several times when detector problems cropped up. The last year of
Lep2 running (2000), where things were really being pushed by the machine,
the track record was:

Z Running needed at Lep2:
------------------------
=>per detector<= 3/pb at the beginning of the year, and
" one run of 0.5/pb during the year

So, we propose then to use the following working hypothesis:

Z Running for ILC:
-----------------
=>per detector<= 10/pb at the beginning of a year, and
" one run of 1/pb during a year

since the detector(s) will be more complicated.

If I remember correctly, the projected Z-pole luminosity for
Tesla for "calibration" (i.e. no special beam gymnastics to push up the
luminosity like would be needed for the ``GigaZ'') would be 10^32/cm^2sec
so that calibration at the beginning of the year would take
=>per detector<= 30hours of beam and during the year =>per detector<=
3hours of beam.
To repeat, this is just a guess, but at least it is based on
past experience.

Of course during the commissioning of the detector at the
beginning of collider operation, much more Z-peak data will be needed to
calibrate/align the subdetectors. This is best estimated by the Ecal.