hera_minutes_020219.html

The re-installation of the modified absorbers NR and SR was completed last week. The new vertical collimators (NL/SL 6) were installed on Thursday.
The GO and GG magnets were cooled down again starting on Friday. (GO south had to be warmed up again due to a cryogenics problem, was cold again yesterday).
The interlock was set yesterday afternoon. First positron beam injection started last night. Beam was stored early this morning with H1 and ZEUS solenoids and HERA B magnet on.
BPMs at the IRs are being studied today.
A new massaging procedure of the proton machine magnets is in preparation. It will include the electron machine magnets. The goal is to reduce the refill time by about 1 hour.
The grounding scheme of the power supply of the GO south magnet was modified. The magnet still trips at 563A. An intermediate optics (GO quad at 540A) was prepared.

There was some delay closing the detector. Supports of the position sensors of GO and beam pipe had to be modified. The detector was closed on Monday.
The IR magnets were re-surveyed during the access. Results are not yet available.
The SPACAL is ready for background monitoring.
HV of tracking chamber can be turned on starting on Thursday.

The GO magnet was vertically adjusted (0.2 and 0.4mm) during the access.
The detector was closed on Friday.
Some high background spikes were observed in the MVD radiation monitor during injection attempts last night.
HV of tracking chamber can be turned on starting on Thursday.
A few hours of stable positron beam is required to check the luminosity monitor.

The Silicon detector was installed as scheduled.
The target is ready to operate.
Will provide background information.
The beam loss monitor is ready (signal is sent to HERA, beam abort is not yet implemented).

F.Willeke announced a meeting to present topics, e.g. alignment, calculation of synchrotron radiation, field measurements of magnets, which could be pursued by individuals from the experiments.

Uwe Schneekloth