Minutes of HERA Meeting      16.10.2001

Summary of HERA Status

• The goal of last week was to see first collisions in ZEUS. This was not quite achieved due to problems during proton ramping, technical problems and commissioning of the ZEUS luminosity monitor.
• Acceleration of the proton beam was improved. Transmission between injection and intermediate optics was very difficult. This was improved by implementing 2 intermediate optics. There are no significant problems during the ramp anymore. Some work is still needed on the reference magnets.
• A longitudinal beam scan at H1 was done to study the optics. Analysis is in progress.
• There have been several failures of the GO/GG magnets in the north IP. The current lead cooling is very critical and not sufficiently stable. An access is required to repair/exchange a temperature sensor on the leads.

ZEUS

• The timing of the luminosity photon detector was not correct last week. This was corrected on Friday. First photon signals in the lumi monitor with both beams in the machine were observed on Saturday after the large vertical tilt of the positron beam at the IP was reduced. The detector had been shielded by the upstream collimator and spectrometer module. First signals were also observed in the HERA synchrotron radiation monitor in front of the photon detector. The position detector showed reasonable beam profiles.
• Shift crew will move to ZEUS hall on Monday.
• Request for short access (FMUON toroid).
• Requested stable proton beam after Wednesday next week, to be scheduled next meeting.

H1

• Performed a threshold scan of the luminosity monitor. Threshold is now set to 3 GeV. Working on rate of individual bunches for luminosity calculation.
• Observed some high backgrounds from Saturday to Sunday.
• Will start shifts next week.
• Requested short access for maintenance of liquid argon calorimeter and work on cooling.

HERMES

• Background rates improved.
• The effect of the transverse target magnet on the positron beam has not been studied yet. Will be done next positron fill.
• Request for access to exchange a broken glass tube.

HERA B

• Preparing commissioning of wire movement.
• Request stable proton beam next week.

Schedule

• Study of HERMES target magnet: next positron fill.
• Tomorrow 8:00 to 12:00hrs: access.
• Tomorrow afternoon: positron beam only
• Continue setting up collisions in south and north IPs.

                Uwe Schneekloth