D2n Run Plan 2020-1pass

See d2n 1-pass Running page for additional detail.

NOTES

• If the ps1 setting is > 5 (true prescale > 17), then the EDTM rate must be increased
  • See Hall C EDTM Pulser, use the dial to increase/decrease the rate -- Call the RC for instructions.
  • ps1=0..5 then set EDTM rate to 120 (Default)
  • ps1=6 then set EDTM rate to 240
  • ps1=7 then set EDTM rate to 480
• Hall C Shift Crew must monitor the 'Parity DAQ' and run the ./FlipPCvaluesHallC script on every IHWP change!!
  • Give Hall B a heads-up before the flips
  • See Charge Feedback Parity DAQ in the How-tos
• Every time the Reference Cell contents are changed Shift Crew must make a log entry AND replace the post-it note on the Reference Cell control panel!
• Record the pressure in your Shift Summary Log at both Start and End of each run
• Fast Raster Coil 'B' is off when at 1-pass so the "FRB" raster plots will be empty/spikes. That is OK.
  • The "FRA" Raster plots should look normal, however!

DONE Beam Energy Measurement (1 hour)

• Accelerator driven process -- will happen following initial beam checkout into the Hall

DONE Reference Cell Empty, Hydrogen (H2), Carbon Cross Sections (3--4 hours)

 Goals 
 - To measure carbon, hydrogen elastic cross sections as a cross check of data quality
 - To measure backgrounds from glass cell and beamline windows (Reference-VAC)

 Setup
 - Beam Current: 5--15 uA and DAQ rate-limited, raster always ON (4mm diameter)
 - Target:       Reference Cell: C-Foil, vacuum, and H2 @ 135 psig
 - Detectors:    All scintillator bars on

 Spectrometer Setup (with HMS 11.7 deg, SHMS 8.5 deg)
 - HMS setting: 11.7 deg, -2.08234 GeV/c (electron QE)  -- Jan 3He elastic settings
 - SHMS setting: 8.5 deg, -2.12860 GeV/c (electron QE setting, but focus on 3He elastic events) -- Jan 3He elastic settings

 Procedure
 - Set spectrometers at the required settings, ensure all scintillator bar HV is ON

 - Move to Carbon-Foil
 - Keep beam current the same as the above Empty Cell run, check rates and
   prescale factors (Save PS file if changed). Goal is to reach (3.5-4)kHz DAQ
   rate on both HMS and SHMS. If rates too low, increase the beam current but
   do not exceed 30uA. If rates too high, prescale it down and do NOT drop
   current below 10uA unless raw rates in the pretriggers exceed 500 kHz.
 - Take one 45-minute run (both arms)
 - While this run is going, you can evacuate the reference cell if necessary

 - Evacuate Reference Cell (to vacuum), record the pressure reading in the Start_Run entries.
 - Ask MCC for 10uA raster ON (4mm dia), check rates and prescale factors
   (Save PS file if changed). Goal is to reach (3.5-4)kHz DAQ rate on both HMS
   and SHMS. If rates too low, increase the beam current but do not exceed
   30uA. If rates too high, prescale it down and do NOT drop current below
   10uA unless raw rates in the pretriggers exceed 500 kHz.
 - Take one 45-minute run (both arms), make sure there are no less than 10,000 events for each of HMS and SHMS.
 - Record the pressure in your Shift Summary Log at both Start and End of each run

 - Fill Reference Cell to 135 psig of hydrogen gas;
 - Keep beam current the same as the above Empty Cell run, check rates and
   prescale factors (Save PS file if changed). Goal is to reach (3.5-4)kHz DAQ
   rate on both HMS and SHMS. If rates too low, increase the beam current but
   do not exceed 30uA. If rates too high, prescale it down and do NOT drop
   current below 10uA unless raw rates in the pretriggers exceed 500 kHz.
 - Take one 45-minute run (both arms), apply ztar and W cut and make sure H2 elastic
   events from the H2 gas are no less than 10,000 for each of HMS and SHMS.
 - Record the pressure in your Shift Summary Log at both Start and End of each run

DONE No Target Run

 Goals 
 - To measure beam-line window contributions alone

 Setup
 - Beam Current: 5--15 uA and DAQ rate-limited, raster always ON (4mm diameter)
 - Target:       NO TARGET
 - Detectors:    All scintillator bars on

 Spectrometer Setup (with HMS 11.7 deg, SHMS 8.5 deg)
 - Same as above

 Procedure
 - Take 30 minute run (both arms)

DONE 3He Reference Cell Runs (N2 and 3He Pressure Curves, False Asymmetries) (5hrs ideal, 3 hrs min)

** We did skip N2; only He3 was completed for this portion **
** NOTE: Call RC at this point.  We may skip the N2 setting 
            and just do the 3He if the target polarization is OK **

 Goals 
 - For empty cell, to determine window background for elastic setting
 - For N2, need 5 points at 0.5, 1.0, 2, 4 and 8 atm, 10,000 N2 elastic events for each pressure setting and each spectrometer.
 - For 3He, need 6 points at 1, 2, 4, 6, 8 and 10 atm, 10,000 3He elastic events for each pressure setting and each spectrometer.
 - Reference cell must be filled with 3He last, and do NOT pump the 3He gas out!
 - Time: couple of hours assuming 50% beam efficiency

 Setup
 - Beam Current: 5--10uA, raster always ON (4mm diameter). Do not drop currents below 10uA unless raw rates in the pretriggers exceed 500 kHz.
 - Target:       Reference Cell, Empty, filled with N2, filled with 3He (last)
 - Detectors:    We will need to keep only 2 scintillator bars ON to take mostly 3He elastic and limit quasi-elastic scattering events. 
 - Use these settings: Scintillator Settings
   A1n notes: hclog 3756736, hclog 3760238
   - HMS Detectors: turn off paddles 1-6 on 1X plane and paddles 1-6 on 2X plane
   - SHMS Detectors: keep only paddles 7,8 of 1X plane, and paddles 7,8,9 of 2X ON, all others off;
   - SHMS (continued): Also suggest for 1Y keep only 7 on, all others off, although this will depends on how well the collimators works

 Spectrometer Setup (with HMS 11.7 deg, SHMS 8.5 deg)
 - HMS setting: 11.7 deg, -2.08234 GeV/c (electron QE)  -- Jan 3He elastic settings
 - SHMS setting: 8.5 deg, -2.12860 GeV/c (electron QE setting, but focus on 3He elastic events) -- Jan 3He elastic settings

 Procedure
 - Set spectrometers at the required settings, target at the Reference Cell position.
 - Make sure the correct scintillator bars are ON.
 - Start at for 5 uA raster ON (4mm dia), check trigger rates and PS factors.
   Ideally we would like to see (3.5-4)kHz DAQ rates. If rates are too high,
   use Prescaling (save PS file if changed). If rates are too low, increase
   beam current but do not exceed 30uA.  Ensure that the livetimes are >80%
   in each arm.

 Nitrogen Pressure Curve
 - Evacuate cell to vacuum and take one 20-minute run.
 - Fill the cell (slowly) to 380 Torr with N2, take one 20-minute run.
 - Fill the cell (slowly) to 1 psig, take one 20-minute run.
 - Fill the cell to 15 psig, take one 20-minute run.
 - Fill the cell to 45 psig, take one 20-minute run.
 - Fill the cell to 75 psig, take one 20-minute run.
 - Fill the cell to 105 psig, take two 30-min runs and flip the IHWP in between

 He3 Pressure Curve
 - Done Evacuate cell to vacuum and take one 20-minute run.
 - Done Fill the cell (slowly) to 380 Torr with He3, take one 20-minute run.
 - Done Fill the cell (slowly) to 1 psig, take one 20-minute run.
 - Done Fill the cell to 15 psig, take one 20-minute run.
 - Done Fill the cell to 45 psig, take one 20-minute run.
 - Done Fill the cell to 75 psig, take one 20-minute run.
 - Done Fill the cell to 105 psig, take one 20-minute run.
 - Done Fill the cell to 135 psig, take 1 30-min run
   - Done Flip the IHWP and run the flipper script for the Parity DAQ Charge Feedback Parity DAQ
 - Done Fill the cell to 135 psig, take 1 30-min run

 - Important: After these runs are completed, do NOT pump out the 3He gas!

 Things to watch for
 - These reference cell runs must be taken with exactly the same spectrometer and scintillator settings as polarized 3He elastic asymmetry runs (see next).
 - Beam current should not be below 10uA (BCM accuracy) and should not be above 30uA (glass cell safety).
 - For each gas pressure setting (except for empty cells), need 10,000 events from gas alone (apply ztar cuts) for each of HMS and SHMS.

DONE Reference Cell He3 Cross Sections (1 hour)

 - Reference Cell should already be set to 135 psig of He3 gas;
 - Turn ON all scintillator paddles
 - Check rates and prescale factors (Save PS file if changed). Goal is to reach (3.5-4)kHz DAQ
   rate on both HMS and SHMS. If rates too low, increase the beam current but
   do not exceed 30uA. If rates too high, prescale it down and do NOT drop
   current below 10uA unless raw rates in the pretriggers exceed 500 kHz.
 - Take one 45-minute run (both arms)
 - Record the pressure in your Shift Summary Log at both Start and End of each run

Polarized 3He Runs, 3He elastic and QE longitudinal Asymmetries (16 hours)

 Goals 
 - To measure physics longitudinal asymmetry of 3He elastic (on SHMS) and QE (on HMS) scattering. 
 - If precision is high, this cross checks PbPt from Moller and Target Polarimetry. 
 - If precision is low, at the minimum we should determine the sign of asymmetries.
 - Experts must watch EDTM rate (Brad).

 Setup
 - Beam Current: 10--15uA, raster always ON (4mm diameter)
 - Target:      Polarized 3He Cell
 - Target spin direction: 180 deg (to start)
 - See Target Field Runplan for coil currents settings.
 - Time: total 12--16 hours of data taking, flip beam IHWP every ~4 hours. Do
   target NMR every 4--5 hours (ask TO), but always before and after the full data taking.

 Spectrometer Setup (with HMS 11.7 deg, SHMS 8.5 deg)
 - HMS setting: 11.7 deg, -2.08234 GeV/c (electron QE)  -- January setting
 - SHMS setting: 8.5 deg, -2.12860 GeV/c (electron QE setting, but focus on 3He elastic events) -- January setting

 - Use these settings when requested below: Scintillator Settings
   - All bars are ON to start with
   - HMS Detectors: turn off paddles 1-6 (or 1-9) on 1X plane and paddles 1-6 (or 1-9) on 2X plane
   - SHMS Detectors: keep only paddles 7,8 of 1X plane, and paddles 7,8,9 of 2X ON, all others off;
   - SHMS (continued): Also suggest for 1Y keep only 7 on, all others off, although this will depends on how well the collimators works
   A1n notes: hclog 3756736, hclog 3760238

 Procedure
 - Set target at the Polarized 3He Cell position, spin 180 deg. (should be the current setting)

 - Done Take an NMR/pNMR before starting this section

 - Ask MCC for 10 uA raster ON (4mm dia), check trigger rates. Goal is to reach (3.5-4)kHz DAQ rates.
 - If rates too high, adjust PS factors (save PS file if changed!) and/or drop beam current 
   but do not go below 10uA unless raw rates in the pretriggers exceed 500 kHz.
 - If rates too low (unlikely), increase beam current but do not exceed 30uA.

 * Done Take 1 60-minute run (ALL BARS ON)

 - Done Turn off HMS scintillator bars as described above
 - Done Turn off SHMS scintillator bar as described above
 * Done Take 3 60-minute runs
   - Immediately check that you turned off the paddles you intended in the online monitor! See HCLOG 3851420

 - Done Take an NMR/pNMR

 - Done  Call MCC and ask beam IHWP to be flipped.  Need to inform other halls prior to the switch.
 - Done  Follow the instructions to run the 'Flipper script' in the Parity DAQ charge feedback system! See Charge Feedback Parity DAQ in the How-tos
 * Take 4 60-minute runs

 - Take an NMR/pNMR

 - Rotate target to Longitudinal/0; Update coil settings as needed

 * Take 4 60-minute runs

 - Take an NMR/pNMR
 - Call MCC and ask beam IHWP to be flipped.  Need to inform other halls prior to the switch.
 - Follow the instructions to run the 'Flipper script' in the Parity DAQ charge feedback system! See Charge Feedback Parity DAQ in the How-tos

 * Take 3 60-minute runs

 - Turn all bars ON
 * Take 1 60-minute run (ALL BARS ON)

 - Take an NMR/pNMR

 Things to watch online
 - Ensure the correct scintillator bars are on (We need 3He elastic events in SHMS and QE events in HMS)
 - Apply z cuts to isolate events scattered from 3He gas (We do not want events from the glass windows!)
 - Apply W or dp cuts to isolate 3He elastic (SHMS) or QE(HMS) events from others.
 - For HMS, run online script to ensure we see physics asymmetry. Plot asymmetry as function of nu (=E-E'). 
 - For SHMS, run online script to ensure we see physics asymmetry. Plot asymmetry as function of W(3He). 

 Predictions
 - QE asymmetry (HMS) predictions are given in hclog 3759756. 
 - Elastic 3He asymmetry (SHMS) is predicted to be 2.5% on SHMS, with Pb=0.8, Pt=0.5 and fN2=0.9 gives Ameas=0.9%.
 - Important: would like to have more than 6% of the full rate on SHMS to come from 3He elastic.

Polarized 3He Elastic Longitudinal Asymmetry (until end of 1-pass running)

3He Asyms for 2.18 GeV/c (S. Barcus, S. Li)

• Continue with the Pol He3 Elastic group's run plan and continue stepping the SHMS out in angle) until we run out of beam time.

  • Rotate target back to 180deg
  • SHMS set to 11.0 deg to start, -2.08234 GeV/c (? Confirm)
  • HMS will rotate to 18.5 deg, -2.12860 GeV/c (? Confirm) and park there for remaining 3He Elastic Asym running

• Settings to be confirmed by Shujie, Scott

• new runplan (0918) TBD

• Note: These values are all estimates. Optimize current and prescale values (using the el_clean trigger ps3) to produce a data rate of ~4 kHz!

1 pass runplan

Kinematics	Angle (degree)	Ep (GeV)	Current (uA)	length (beam on hours)	Prescale Setting (PS3)	estimated rate (total)
HMS Kin-1A	11.7	2.0823	5	D2n Systematics	1	2219
HMS Kin-1D	17	2.0823	30	Remaining time	0	2003
SHMS Kin-2A	8.5	2.1289	5	D2n Systematics	3	3045
SHMS Kin-2C	11	2.1289	5	2	1	2643
SHMS Kin-2D	15	2.1289	20	2	0	3971

 Goals 
 - To measure physics longitudinal asymmetry of 3He elastic scattering to (2-3)% relative, cross check PbPt from Moller and Target Polarimetry

 Setup
 - Beam Current: 5--10uA, raster always ON (4mm diameter)
 - Target:      Polarized 3He Cell, Reference Cell
 - Target spin direction: 180deg only
 - See Target Field Runplan for coil currents settings.
 - Detectors:    We will need to keep only a few scintillator bars ON to accept 3He elastic and limit quasi-elastic scattering events. 
   - HMS Detectors: turn off paddles 1-6 on 1X plane and paddles 1-6 on 2X plane
   - SHMS Detectors: keep only paddles 7,8 of 1X plane, and paddles 7,8,9 of 2X ON, all others off;
   See Scintillator Settings
 - Parity check: Inform Hall A prior to taking data to make sure they set the charge asymmetry feedback cutoff at 2uA.
 - Time: total 8 hours of data taking with even split between IHWP settings
   Full target polarimetry measurements at the start and the end, plus pNMR
   (pulsed NMR) only every two hours or after each target spin flip.

 Procedure
 - Verify the correct Scintillator bars are ON.
   - Scintillator Bar Settings
 - Move target to Polarized 3He Cell position, spin polarization at 180 deg.
 - Perform one full set of NMR, (EPR?), pNMR polarimetry measurements before taking data, and every 4 hours thereafter
 - Set SHMS and SHMS DAQs to use EL_clean (T3) triggers unless unprescaled T1 rates are < 3.5 kHz
 - Ask MCC for 10uA raster ON (4mm dia), check trigger rates. Goal is to reach
   3.5kHz--4kHz DAQ rates. If rates too high, adjust PS factors (save PS file if
   changed!). If rates too low (unlikely), increase beam current but do not
   exceed 30uA.

 - Want at least 2--4 hours of beam on target for inital(8.5 deg) point; flip IHWP at half-way mark

 Things to watch online
 - Ensure the correct scintillator bars are on (We need 3He elastic events!)
 - Apply z cuts to isolate events scattered from 3He gas (We do not want events from the glass windows!)
 - Apply W or dp cuts to isolate 3He elastic events from others.
 - Run online script to ensure we see physics asymmetry. HMS and SHMS should
   see the same asymmetry. Asymmetry should flip sign with beam IHWP switch
   and target spin flip.

 - Expected asymmetries (3He elastic only): Aphys=5.0% Ameas~2% at 11.7 deg, or Aphys=5.8% Ameas=2.3% at 12.5 deg, if using Pt=50%, Pb=85%, N2 dilution 0.92.
 - Expected uncertainties dA/A=2% (goal) or 3% (minimum).

Important Scripts

• Elastic Electron Count Script:
  • Location: /home/cdaq/polhe3/production/hallc_online/analysis/elastic/el_asym_(s)hms.cxx
  • Description: These scripts count the number of elastic electrons in a data run after applying various cuts.
  • Usage: To use these scripts with the correct relative paths they must be executed from the ~/polhe3/production/hallc_online directory. They can be executed as 'root -b -q "analysis/elastic/el_asym_shms.cxx(11091)"'.
  • Output: The analysis plots can be found in ~/polhe3/production/hallc_replay/MON_OUTPUT/ANALYSIS_HISTOS/run#_analyzed/.
• Elastic Asymmetry Script:
  • Location: /home/cdaq/polhe3/production/hallc_online/analysis/elastic/asym_elastic.py
  • Description: This script will calculate the elastic asymmetry for runs listed in /home/cdaq/polhe3/production/hallc_online/database/(S)HMS_run_table.csv. The momentum and angle arguments will display only runs with settings near those given. The elastic counts used for this calculation come from calling the el_asym_(s)hms.cxx scripts mentioned above. Acceptance cuts for elastic electrons can be changed in those scripts.
  • Output: The plot of the asymmetries is written to ~/polhe3/production/hallc_online/progress/asym_elastic_(s)hms.png.
    • Usage: 'python3 asym_elastic.py SHMS -p 2.17 -a 8.5 -t 0.1 --estimate=0.026 --factor-qe=0.80 --date-start=2020-01-12'

Positional Arguments:

arm Spectrometer Arm (HMS or SHMS)

Optional Arguments:

-h, --help show this help message and exit

-p MOMENTUM momentum setting (GeV)

-a ANGLE angle setting (degree)

-t TOLERANCE absolute tolerance for settings

--date-start START start date

--date-end END end date

--counts-min CMIN minimum event counts for valid elastic runs

--estimate ESTIMATE estimated asymmetry for this setting (without any corrections)

--factor-qe F_QE dilution factor from Quasi-Elastic asymmetries

--run-script run count script if output does not exist

• Paddle Optimization Script:
  • Location: /home/cdaq/polhe3/production/hallc_online/analysis/hodo/draw_paddles_(s)hms.cxx
  • Usage: From /home/cdaq/polhe3/production/hallc_online/ execute 'root -b -q "analysis/hodo/draw_paddles_shms.cxx(9788)"'.
  • Output: The analysis plots can be found in ~/polhe3/production/hallc_online/paddle_plots/.