Minutes of HERA Meeting
28.12.2004
HERA
F.Willeke summarized HERA operation of last week.
- Machine studies (beam based alignment and proton optics studies) were
completed last week. The accelerators were turned off 23.12.
- Yesterday the machine was turned on without problems. First
collisions with low currents were achieved in the evening. The
number of bunches was increased to 120 last night.
- Background oscillations were observed during luminosity operation.
The source is most likely in the south IR, probably a quadrupole
magnet, is being studied. In case of a break, the voltage across
the BU magnets will be checked. The GA power supply problem which
was causing large background spikes was solved last week.
- There are indications that the magnet bridge NL moved by 0.4mm.
- HERA will continue to optimize the background conditions.
ZEUS
- The detector was turned on relatively smoothly and is ready for data
taking. The only problem is
the luminosity monitor. The specific luminosity was wrong, probably
due to wrong bunch current information.
- The proton background was unstable last night.
H1
- The solenoid and luminosity monitor are on. Last night the background
rate was too high for longer operation.
HERMES
- Will start shifts tomorrow.
Schedule
- Continue luminosity operation with 120 bunches. Improve orbits and
background conditions. Try to find source of background oscillations.
- The GO/GG magnets will be warmed up during the maintenance day next
week unless the integrated electron current is too small.
The final decision will be made Monday morning.
ZEUS is the coordinating experiment.
Uwe Schneekloth