I first put this in the tracking in learning how to do
the "discussion forum", but now I see it should be put here
in the overall concept.
Apologies if you have already recieved this. 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.
During commissioning at the very beginning of collider
operation, much more Z-peak running will be needed. This question is
best answered by the Ecal.