|Re: z-Position of the Lumi Monitor [message #9100 is a reply to message #9076]
||Wed, 29 July 2009 15:58
Registered: April 2004
Dear Miriam, dear Tsito,|
Bernd will be back Thursday next week. Concerning the
beam pipe: The wall thickness usually is 2% of the diameter,
at least for something like Al.
The size of the beam pipe is as given by HESR at the moment.
This comes from a time before any lumi monitor. Here input
is actually needed from you. Best coordinate closely with the
HESR people. Clearly the numbers are not fixed yet for the
part downstream of the target spectrometer.
Within the 2m space for the lumi monitor any adjustment of
beam pipe diameters has to take place. This holds especially
for the outgoing direction. For the upstream side of course
physics plays a role: All elastically scattered pbar you want to
measure with the lumi monitor should be contained in the
pipe. Maybe the best strategy is to open up early on, e.g. soon
after the MVD to the required diameter and then have a rather
big pipe all the way to the lumi monitor.