M.Bieler summarized HERA operation of last week,
see transparency
Last week the HERA performance was excellent. Luminosity operation
was only interrupted twice, due to the thunderstorm on Wednesday and a
problem with the air conditioning of a transmitter power supply.
The delivered luminosity was about 6pb-1. Polarization was between
40 and 50%.
The large coasting beam production was cured by repairing a defective
cable connection as reported last week.
There was a 20% difference of luminosity at the north and south
interaction regions. This was cured by changing the vertical proton
angle at the IP.
Proton collimators had to be readjusted on Saturday after a global
orbit correction.
ZEUS
Efficient data taking with good background conditions.
The data taking efficiency is increasing.
Last night there was a problem with the online luminosity display.
HERMES was asked to stop the end-of-fill run after 1 hour.
H1
Smooth data taking. Chamber currents were usually below the expectation.
The delivered luminosity was 5.6pb-1, 4.3pb-1 were written to tape
with HV on.
Satellite bunches of up to 10% were observed using the beam pickup
monitor. They should be reduced.
The damage of the forward Si tracker is continuing (65% is defective).
The low and high voltages of the FST were turned off. Some damage is
also seen in the backward Si tracker.
H1 would like to remove the FST and BST during the shutdown in order
to equip the front-end electronics with more radiation hard chips.
This could be done in 7 weeks, extending the present shutdown by 2 days.
A shutdown of similar length would be required next year for
re-installation.
The shutdown schedule will be discussed in the next HERA coordination
meeting.
HERMES
HERMES was happy with the beam conditions. Some background tuning was
necessary at the beginning of the fills.
The LPOL is not working. An access of about 1/2h is required to
check and/or remove the calorimeter.
Polarimeters
The TPOL laser tripped on Sunday. No polarimeter information is
available for the first half of Sundays luminosity fill.
Schedule
Continue luminosity operation.
Start HERMES high density end-of-fill running at Ie=18mA. Call HERA
after 45 minutes. Stop run after 1 hour.
The high voltages of the experiments should be off 15
minutes after the "Please turn off in 15min message" appears.
Tomorrow during day time 1/2h access for LPOL.
The orientation of the spin rotators will be changed during the
July maintenance day.