Difference between revisions of "Commissioning Run Plan"

Revision as of 13:37, 14 October 2014

For the Fall of 2014 assume:

• Maximum beam current = 20 μA but for short times it can go higher for boiling studies and BCM calibration.
• 7.3 GeV @ 4 pass, 5.5GeV @ 3 Pass and 3.7 GeV @ 2 pass. No five pass beam in the Fall of 2014.
• Angle restrictions with DVCS calorimeter in place:
  1. HRS-BL: 17.9 to 45 degrees
  2. HRS-BR: 46.2 to 74.5 degrees

Pre-beam Checklist

Trigger Checkout (Experts)

* Checkout trigger timing
* Checkout of EDTM (Barak Schmookler)
* Think about adding 60, 100, 150, and 200 ns wide electronic deadtime scalers.
  This has been found to be a robust method for determining electronic deadtime in Hall C and we should think about adding something similar for GMP.

HRS Detector Checkout (Detector Experts)

* Take a long cosmics run with all detectors on.
* Look for dead and hot wires in the wire chambers against an earlier plot to look for any possible inconsistencies in wiring.  Check these against 
  those listed in the current analysis parameters. (Yang Wang)
* Look at ADC distributions for the hodoscopes Gas Cherenkovs and lead glass calorimeters.  Are they all firing? (Barak Schmookler, Longwu Ou)
* Look at TDC distributions for hodoscopes and Gas Cherenkovs.  Is the timing reasonable, any multiple peaks, within timing range, etc? 
  (Barak Schmookler, Longwu Ou)

Commissioning and Calibrations

The following items should be performed during the first 1-1.5 shifts with beam on target:

* Initial trigger checkout with beam.  Check timing and PID thresholds.
* Initial detector checkout with beam.
* Initial checks of beam position and raster.

HRS Checkout (Experts)

The detector checkout is best done using a fairly uniform illumination, which is provided for by 20 μA on the central Carbon target at the following kinematics:

E' = 3.056 GeV, θ = 19 degrees (W² = 2.53 GeV, Q² = 2.43 GeV²). The HRS electron rates should be about 270 Hz.

1. With the above kinematics, take a run (at least 100K events or 10 minutes) and verify that all detector channels are working.
2. Using the same run, produce a ROOT tree, and do the following: make a spectrum of x vs. y at the focal plane. What you should see is a "spider" with 5 legs. The non-straightness of the central legs indicates there is an offset in the Z or Y direction. If you don't see a "spider" or something resembling it, then of of the polarities of the HRS magnets is set wrong (or a magnet is off).
3. Check that the signals are well timed.
4. Determine correct thresholds.
5. Verify all scalers are incrementing.
6. Check for double pulsing and time the wire chamber signals.
7. Are the scintillator signals for on scale in the scintillator ADCs?
8. PID threshold checks.

HRS Detector Calibrations

Beamline

Spectrometer Optics

Luminosity Scans - Low Rate (Target Boiling)