Minutes of HERA Meeting
04.12.2001
HERA
- Last week was spent on understanding the magnet positions and reducing the
synchrotron radiation background after the bridge movements two weeks ago.
- Positrons are now successfully accelerated to 27.5 GeV without high
backgrounds in the ZEUS MVD diodes.
- The BI magnet at about 90m was identified as one source of synchrotron
radiation background.
- Beam based alignment techniques are now giving reasonable results.
- The calibration of the beam position monitors near the IPs was checked.
BPMs at 11 and 15m are now working properly. Readout electronics for
the BPMs <2m is being prepared.
- Optics studies of the positron machine showed no optics errors. The
precision is about 1% of the quadrupole fields. A dispersion error was
found and will be corrected.
- A calibration error of a proton quadrupole magnet (source of a beta beat)
was found and corrected.
- The machine is ready to go higher positron currents.
ZEUS
- The background conditions in the MVD are acceptable now.
- The central tracking detector HV was turned on without beam.
- Yesterday the electronics of the MVD radiation monitor was not working
properly, giving false alarms.
H1
- The detector was turned on without beam.
- Noise in the water Cerenkov detector (part of the luminosity monitor) was
improved.
- Additional background monitors (faster response to synchrotron radiation)
and timing information (SPACAL and scintillators) are in preparation.
HERMES
- Did work on target system.
- Waiting for stable positron beam.
HERA B
- The HERA B magnet has been on, no more power supply trips anymore.
- Request for proton beam running ps file.
Need 6 shifts in December to establish target operation and for calibration
and alignment of detectors. Prefer 60 bunches, interaction rate will be
1.5 MHz.
Schedule
- Go back to positron beam operation this afternoon. The proton beam will
be kept in the machine.
- Stable positron beam for experiments this afternoon.
- If background conditions are acceptable, increase positron beam intensity.
- In general, proton beam will be stored in HERA during stable positron
beam running, background optimization and positron machine studies and can
be used by HERA B parasiticly, except this afternoon when the chamber HV
of the other experiments is turned on. In case the proton beam is lost
it will be re-injected when the stable positron beam period or the machine
physics item under study is completed.
- Continue working on software tools for beam based alignment.
- H1 is the coordinating experiment.
Uwe Schneekloth