Minutes of the HERA Meeting 14.2.2006

HERA startup (F. Willeke):

p startup without problems, faster than scheduled.
New p BPMs N and S taken into operation.
Sat 11.2.06: power main station C failed (cat tripped filter)
  Kryo control affected. Critical since one TTF cavity must stay cold.
  Hall West lost power. Several electronic components damaged upon restart.
  Recovery took until Sun.
Had to skip studies with new low beta optics: postponed.
New proton long feedback taken into operation, shorter bunches observed
(1.8 ns FWHM -> 1.2 ns), but growing again during 5h at 920 GeV. Needs p RF
gain adjustments to prevent growth.
Shorter bunches -> reduced hour glass effect -> 6% more lumi with 18 cm
beta*_v^p optics.
First multibunch damper operated at a high energy p machine, developed
within 1 year: a nice success.

Ongoing: optimize e inj. eff.

Next: establish collisions with last year's optics, but with some
improvements: some wrong quad strength corrected, more sextupole circuits.
Start with 60 bunches, 15 mA e-.

Try e RF conditioning: move tuners to mimic field config. from beam loading.


ZEUS:
Detector ready.
Would like to have stable e- beam at 12 GeV for calib, at 27.6 GeV for
background study.


Hermes:
Installed extra temp sensors on water cooling for the target cell.
No new measurements on target cell heating due to lack of e- beams.

F.Willeke: request to study possible modifications.
R. Heuer: study limitations with spare cell in the lab.

Request to test effect of solenoid on e and p beams: ramp up with beam
on Wed.


Hermes is coordinating experiment.

Daniel Pitzl