Minutes of HERA Meeting
02.04.2002
HERA
- Last week HERA tried to establish colliding beam operation. Collisions
were repeatedly achieved without much problems. Beam steering is still
difficult and not yet done by the operators. The luminosity was not
measured.
- The files (magnet settings and beam orbits) do not reproduce very well.
- The H1 SPACAL rate was relatively high, probably due to particle background.
- Closing of the ZEUS F/RCAL did not work. The beam was lost during the
last few mm of the calorimeter movement.
- The proton intensity is still poor (injection efficiency and losses during
acceleration). It was improved yesterday by changing the PETRA beam
energy. There are now less beam losses during acceleration.
The proton beam lifetime is bad at 60GeV, to be studied.
- There is some progress on beam instrumentation. The BPMs near the IP
are now providing proton and positron beam position information.
- NEG pumps are activated today.
ZEUS
- The position sensors of the survey group show a significant movement
of the GO magnet when the FCAL is being closed. The movement is caused by
magnetic forces between the GO quadrupole coil and the calorimeter
iron (mechanical support of the FCAL and PMT shielding).
The effect will be investigated during the access this afternoon.
Schedule
- Reduce proton beam losses at 60GeV.
- Collide beams with increasing beam intensities.
- Optimize background conditions, turn on detectors.
- Progress on the ZEUS FCAL/GO interference will be discussed Friday
15:00hrs in the HERA control room.
- ZEUS is the coordinating experiments.
Uwe Schneekloth