Plan for CMS HCAL run in 25 nsec test beam 2003

Created on May 21st, 2003 by D.L. after detailed proposal by S.K. - still open for discussion and change .

The main issue for this run is sychronisation of different data paths, i.e. synchronization between RBXs, RMs and individual channels. Next issue is detailed measurement of the calorimeter response as a function of the trigger phase.

Before the start of the beam:

  1. Set up two wedges with electronics and laser/LED system.
    Also setup and test all beam line elements (beam and muon counters, beam chambers etc).
    A critical element is the trigger counters with TDC for phase measurement.
  2. Pedestal runs to check all channels and noise level;
  3. Laser injection to all tiles to measure relative timing;
  4. Adjust timing of all channels based on the laser pulse measurement;
  5. Re-measure the timing with laser to confirm the adjustment.
Install and commission as much hardware for the August run as possible.

25 nsec beam run:

  1. Check all beam line elements and their signals with data;
  2. Phi-eta scan with electrons ( 100 GeV ), muons ( 225 GeV ) and pions ( 300 GeV ) with one or two different settings of "LHC clock" (global timing).
    The scan should include beam at near boundary of phi slices. (eta-phi scan)
  3. At a few fixed eta-phi point(s), change the global timing by one or two nsec steps. (timing scan)
  4. At a few fixed eta-phi point(s), change beam energy (energy scan)
  5. Periodical laser runs to check the stability of timing during the 25 nsec run period.
  6. Adjust HPD HV for equal gain, IF we see large difference in HPD QE*gains.

After the 25 nsec beam run:

Wire source runs (at least twice, in order to check its reproducibility).

Since we will not have ECAL in May, it will probably be difficult to understand e/mu/pi contamination in each beam setting. Resolution and linearity measurements as a function of beam energy and timing might be difficult.