Minutes of HERA Meeting
16.09.2003
HERA
F.Willeke summarized HERA operation of last week.
- The GO/GG magnets were again warmed up last Wednesday. NEG and TSP pumps
were regenerated and activated again. The desorbed gas load was not
significantly less that in the previous week. The results were discussed
in the background task-force meeting. It was decided to continue with the
program, i.e. 12 GeV beam bake-out was done for 3 instead of 4 weeks.
- The positron orbit (files) was re-optimized, ORB measurements and
finding collisions, before starting beam conditioning at 27.5GeV.
- On the weekend collisions were obtained without problems in the south IP.
The luminosity
signal at H1 showed some strange behavior. It is not clear whether the
beams were colliding properly. Reproducing collisions yesterday was
difficult. There was a large beam offset at the north IP.
- Since last week the 7th RF station has been operating again. It was
operated at low power without problems. The interlock is being tested
today.
- New bipolar chopper power supplies for the GO/GG correction coils
are commissioned during the break today.
HERMES
- Shifts started yesterday. Re-commissioning of both polarimeters has
started. Stable positron beam (about 10mA) was requested.
ZEUS
- The calorimeter should be closed whenever possible in order to
establish the orbit correction procedure.
H1
- The luminosity monitor is working properly. The energy threshold was
reduced from 5 to 2GeV on the weekend to increase the sensitivity.
It will be set back to 5GeV.
- Shifts will start on Friday. The chamber gas will be flushed again.
Schedule
- Stable positron beam at 27.5GeV for polarimeter commissioning (about 10mA, 120 bunches plus one isolated bunch) until Wednesday evening or Thursday.
- Continue with polarization studies and 27.5GeV bake-out after polarimeter
commissioning is completed. In addition small intensity proton beam at
920GeV.
- Schedule for open day: dump positron beam 28.09. 06:00hrs, no beam operation Saturday to Monday night, tunnel will be closed 29.09. 15:00hrs, interlocks
set 22:00hrs.
HERMES is the coordinating experiment.
Uwe Schneekloth