Minutes of HERA Meeting
16.04.2002
HERA
- A defective electron quadrupole magnet (QC type magnet at WR152) was
found on Saturday. One on the coils was severely burnt. The magnet
was exchanged on Saturday.
- After the magnet exchange the injection efficiency is much better than
before, at least as good as in 2000. Beam acceleration and going to
luminosity optics is also much easier.
- It took some time to re-start the accelerators after the access.
- On Monday there were several technical problems. The injection kicker
was repaired. The proton 52MHz RF system will be repaired during the
access today.
- Beam orbits are still not very reproducible. Using orbit reference files,
collisions were immediately found yesterday, colliding 11mA (protons)
on 6mA (positrons).
ZEUS
- The RCAL was closed without any problems yesterday evening. Luminosity
dropped by 10 to 20% during closing, but was restored automatically by
the orbit correction procedure.
- Tracking detectors were turned on during collisions last night: FTD1
to full HV, CTD and RTD to about 95%. (The CTD current was very high
at nominal HV.) First ep data were taken since August 2000.
- The additional GO magnet support is being installed today.
H1
- Timing jumps of the HERA HIT system were observed yesterday. This should
now be stable. First preliminary luminosity values were released.
Backgrounds were reduced by a factor of 3 optimizing collimator
positions. HV was not turned last night.
- The toroid magnet will be turned on today. Possible movements of the
magnet bridge will be checked. The toroid will be kept on.
- Want to do a calibration run with GG magnet on before beam injection
this afternoon.
HERMES
- Working on target during the access today.
Schedule
- Regenerate NEG pumps, activate Ti sublimation pumps today.
- Collide beams, similar currents as last night.
- Collide beams with increasing beam intensities. If the background
conditions are very high and are mainly due to synchrotron radiation,
have one fill of stable positron beam.
- The schedule for the weekend will be discussed Friday 15:00hrs, HERA control room.
- ZEUS is the coordinating experiments.
Uwe Schneekloth