[Mott] commissioning plan

[Joseph Grames]

I'm sorry....replace "March" with "February".  I've gotten too far ahead of myself.  :)

----- Original Message -----
From: "Joseph Grames" <grames at jlab.org>
To: mott at jlab.org
Sent: Wednesday, February 5, 2014 4:42:53 PM
Subject: [Mott] commissioning plan

Dear Colleagues,

With today's successful demonstration of 2.2GeV/pass CEBAF will change gears for the next ~month to allow for other activities.  The good news is this includes opportunities over the next ~couple of weeks for Mott commissioning.  While it's too early to forecast the entire period, we are firmly scheduled each day March 10-14 on SWING shift.  Riad, Marty and I will staff these shifts.  The schedule beyond this remains TBD, but has a firm end point of March 20 at 7am.   Our plan is to evaluate our progress next week before biting off more than we can, or are ready, to accomplish in any given day.  We will send out a daily summary and post results to our electronic logbooks for those who would like to participate/comment remotely.

In the meantime, Riad, Marty and refined our goals for next week:

PART I - Configuration
======================
1. Choose rep rate - identify whether 31MHz or 63MHz provides best beam quality at Mott target vs. seed bias and prebuncher
2. Test Mott setup script - completes revision of software to eliminate cryounit changes and integrate target motion 
3. Set TDC timing delay - ensures signal and background events occur similarly from each detector package
4. Repeat PMT HV setup - increase and match PMT signal gain following recent repair of down-dE
5. Final DAQ punchlist - generate punch list of remaining DAQ labeling/cosmetic issues
6. Analysis macro development - produce high quality, high statistics run to generate analysis parameters for systematic studies
7. Beam setup - Set energy KE=5.0MeV crested, polarization transverse (X or Y), helicity reversal 30Hz, real-time, quartet
8. Mott setup - Dump dipole degaussed, 1 micron gold foil
9. Sign-off - Before moving on, a clear assessment of signal/DAQ setup, rates and instrumental asymmetries

PART II - Systematics (coincident energy + TOF spectra to yield rate, physics asymmetry, instrumental asymmetry)
================================================================================================================
1. Beam position - deflect at target Left, Right, Up, Down, Center; estimate position from target ladder
2. Beam intensity - linearity and dead time study over allowed range 0-2 uA
3. Beam spot size - adjust MQJ0L02/MQJ0L02A for aspect ratio and size by factor two
4. Beam energy - change KE is finite steps (4.5MeV, 4.75MeV, 5.00MeV, 5.25MeV, 5.50MeV)
5. Beam energy spread - change cavity phase off crest while retaining KE=5.00MeV (-10deg, -5deg, 0deg, +5deg, +10deg)
6. Stability - long run (~2 hours) to study stability with statistics ~0.25% in 5min bin
7. Target reproducibility - compare pairs of foils (two 1um Au, two 0.5um Au)
8. HC Intensity - test response for intensity asymmetry applied by laser (IA)
9. HC Position/Angle - test response for position difference applied by magnets (HELMAG)
10. Sign-off - Before moving on a reasonable assessment of leading order term (intensity) and systematic issues for future investigation.

PART III - Survey
=================
1. Survey foils - collect ~similar statistics on Au, Ag, Cu to characterize foil and dump events




 







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