D2n Run Plan 2020
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Revision as of 15:42, 28 August 2020 by Brads (talk | contribs) (→SHMS Paddle Configuration Optimized for He3 Elastic Measurement)
Rough / High-level sketch of d2n kinematic settings
Reduced kinematics list to accommodate limited beam time (dropped 1/4 of kinematics)
--------- Running Conditions ----------
E_beam = 10.4 GeV/c I_beam = 30 uA P_beam = 0.80
--------- HMS ----------
E' theta x Q2 W
A -4.2 13.5 0.207 2.414 3.178
B -4.2 16.4 0.305 3.554 2.993
C -4.0 20.0 0.418 5.018 2.806
--------- SHMS ----------
E' theta x Q2 W
X -7.5 11.0 0.527 2.866 1.859
Y -6.4 14.5 0.565 4.240 2.036
Z -5.6 18.0 0.633 5.701 2.046
Run / Shift Schedule
- We started taking on Swing on Aug 7 (took a few days for beam to stabilize)
- Beam is scheduled to turn off 8am, Sept 21 (roughly 6 weeks) [1]
- Hall C Shift Schedule
Data Collection Status
- Data collection status is best monitored using
d2n_status_tableon cdaq@cdaql1
- Data collection status is best monitored using
[cdaq@cdaql1 ~]$ go_analysis pro cdaq@cdaql1:~/polhe3/production/hallc_replay$ d2n_status_table
d2n Collected Data Table [click me to expand]
- Fri 28 Aug 2020 08:12:11 AM EDT
Setting target P th pol n_runs IHWP IN OUT e- yield charge / goal status
Kin-A (hms) POL-HE3 -4.200 13.50 90 82 49.17% 50.83% 2.46e+08 5.91e+07 4.17 / 6.06 68.8%
Kin-A (hms) POL-HE3 -4.200 13.50 270 4 100.00% 0.00% 1.26e+07 6.14e+07 0.21 / 6.06 3.4%
Kin-A (hms) POL-HE3 -4.200 13.50 0 0 0.00 / 0.69 0.0%
Kin-A (hms) POL-HE3 -4.200 13.50 180 0 0.00 / 0.69 0.0%
Kin-A (hms) REF-N2 -4.200 13.50 N/A 13 0.00% 100.00% 2.34e+07 1.34e+08 0.18 / 0.22 79.7%
Kin-A (hms) REF-H2 -4.200 13.50 N/A 6 0.00% 100.00% 1.46e+07 6.85e+07 0.21 / 0.22 96.8%
Kin-A (hms) REF-HE3 -4.200 13.50 N/A 15 0.00% 100.00% 2.40e+07 5.39e+07 0.44 / 0.22 202.1%
Kin-A (hms) REF-VAC -4.200 13.50 N/A 9 0.00% 100.00% 8.35e+06 4.01e+07 0.21 / 0.22 94.5%
Kin-A (hms) C-OPTICS -4.200 13.50 N/A 10 0.00% 100.00% 1.68e+07 9.15e+07 0.18 / 0.08 228.8%
Kin-A (hms) EMPTY -4.200 13.50 N/A 5 0.00% 100.00% 3.83e+06 2.48e+07 0.15 / 0.08 193.3%
Kin-B (hms) POL-HE3 -4.200 16.40 90 0 0.00 / 6.13 0.0%
Kin-B (hms) POL-HE3 -4.200 16.40 270 0 0.00 / 6.13 0.0%
Kin-B (hms) POL-HE3 -4.200 16.40 0 0 0.00 / 0.61 0.0%
Kin-B (hms) POL-HE3 -4.200 16.40 180 0 0.00 / 0.61 0.0%
Kin-B (hms) REF-N2 -4.200 16.40 N/A 0 0.00 / 0.22 0.0%
Kin-B (hms) REF-H2 -4.200 16.40 N/A 0 0.00 / 0.22 0.0%
Kin-B (hms) REF-HE3 -4.200 16.40 N/A 0 0.00 / 0.22 0.0%
Kin-B (hms) REF-VAC -4.200 16.40 N/A 0 0.00 / 0.22 0.0%
Kin-B (hms) C-OPTICS -4.200 16.40 N/A 2 0.00% 100.00% 9.98e+05 8.42e+06 0.12 / 0.08 148.1%
Kin-B (hms) EMPTY -4.200 16.40 N/A 2 0.00% 100.00% 4.33e+05 3.37e+06 0.13 / 0.08 160.3%
Kin-C (hms) POL-HE3 -4.000 20.00 90 12 23.48% 76.52% 6.08e+06 8.80e+06 0.69 / 6.05 11.4%
Kin-C (hms) POL-HE3 -4.000 20.00 270 61 63.28% 36.72% 2.21e+07 8.53e+06 2.59 / 6.05 42.8%
Kin-C (hms) POL-HE3 -4.000 20.00 0 0 0.00 / 0.69 0.0%
Kin-C (hms) POL-HE3 -4.000 20.00 180 17 69.53% 30.47% 2.26e+06 3.05e+06 0.74 / 0.69 106.8%
Kin-C (hms) REF-N2 -4.000 20.00 N/A 10 0.00% 100.00% 6.65e+06 3.99e+07 0.17 / 0.22 75.8%
Kin-C (hms) REF-H2 -4.000 20.00 N/A 7 0.00% 100.00% 8.23e+05 2.65e+06 0.31 / 0.22 141.1%
Kin-C (hms) REF-HE3 -4.000 20.00 N/A 10 0.00% 100.00% 1.25e+06 2.90e+06 0.43 / 0.22 196.2%
Kin-C (hms) REF-VAC -4.000 20.00 N/A 6 0.00% 100.00% 3.46e+05 1.69e+06 0.20 / 0.22 92.9%
Kin-C (hms) C-OPTICS -4.000 20.00 N/A 8 0.00% 100.00% 7.49e+05 1.38e+06 0.54 / 0.50 108.6%
Kin-C (hms) EMPTY -4.000 20.00 N/A 9 0.00% 100.00% 2.10e+05 1.02e+06 0.21 / 0.50 41.1%
Setting target P th pol n_runs IHWP IN OUT e- yield charge / goal status
Kin-X (shms) POL-HE3 -7.500 11.00 90 96 45.83% 54.17% 5.06e+08 1.05e+08 4.81 / 6.06 79.3% Kin-X (shms) POL-HE3 -7.500 11.00 270 57 56.27% 43.73% 2.50e+08 1.13e+08 2.22 / 6.06 36.7% Kin-X (shms) POL-HE3 -7.500 11.00 0 0 0.00 / 0.69 0.0% Kin-X (shms) POL-HE3 -7.500 11.00 180 5 52.32% 47.68% 2.66e+07 9.56e+07 0.28 / 0.69 40.0% Kin-X (shms) REF-N2 -7.500 11.00 N/A 24 0.00% 100.00% 7.12e+07 2.75e+08 0.26 / 0.22 117.6% Kin-X (shms) REF-H2 -7.500 11.00 N/A 9 0.00% 100.00% 2.68e+07 1.01e+08 0.26 / 0.22 120.1% Kin-X (shms) REF-HE3 -7.500 11.00 N/A 12 0.00% 100.00% 3.74e+07 1.10e+08 0.34 / 0.22 154.6% Kin-X (shms) REF-VAC -7.500 11.00 N/A 8 0.00% 100.00% 1.76e+07 7.47e+07 0.24 / 0.22 107.3% Kin-X (shms) C-OPTICS -7.500 11.00 N/A 10 0.00% 100.00% 1.75e+07 9.00e+07 0.20 / 0.08 243.8% Kin-X (shms) EMPTY -7.500 11.00 N/A 9 0.00% 100.00% 8.24e+06 4.36e+07 0.19 / 0.08 236.2%
Kin-X-pos (shms) REF-HE3 7.500 11.00 N/A 3 0.00% 100.00% 2.82e+04 3.10e+05 0.09 / 0.22 41.5%
Kin-Y (shms) POL-HE3 -6.400 14.50 90 0 0.00 / 6.13 0.0% Kin-Y (shms) POL-HE3 -6.400 14.50 270 0 0.00 / 6.13 0.0% Kin-Y (shms) POL-HE3 -6.400 14.50 0 0 0.00 / 0.61 0.0% Kin-Y (shms) POL-HE3 -6.400 14.50 180 0 0.00 / 0.61 0.0% Kin-Y (shms) REF-N2 -6.400 14.50 N/A 0 0.00 / 0.22 0.0% Kin-Y (shms) REF-H2 -6.400 14.50 N/A 0 0.00 / 0.22 0.0% Kin-Y (shms) REF-HE3 -6.400 14.50 N/A 0 0.00 / 0.22 0.0% Kin-Y (shms) REF-VAC -6.400 14.50 N/A 0 0.00 / 0.22 0.0% Kin-Y (shms) C-OPTICS -6.400 14.50 N/A 2 0.00% 100.00% 1.21e+06 1.02e+07 0.12 / 0.08 147.9% Kin-Y (shms) EMPTY -6.400 14.50 N/A 2 0.00% 100.00% 7.35e+05 5.73e+06 0.13 / 0.08 160.4%
Kin-Z (shms) POL-HE3 -5.600 18.00 90 0 0.00 / 6.05 0.0% Kin-Z (shms) POL-HE3 -5.600 18.00 270 11 100.00% 0.00% 2.54e+06 4.54e+06 0.56 / 6.05 9.2% Kin-Z (shms) POL-HE3 -5.600 18.00 0 0 0.00 / 0.69 0.0% Kin-Z (shms) POL-HE3 -5.600 18.00 180 19 60.72% 39.28% 4.13e+06 4.74e+06 0.87 / 0.69 125.2% Kin-Z (shms) REF-N2 -5.600 18.00 N/A 0 0.00 / 0.22 0.0% Kin-Z (shms) REF-H2 -5.600 18.00 N/A 8 0.00% 100.00% 1.38e+06 4.55e+06 0.30 / 0.22 137.5% Kin-Z (shms) REF-HE3 -5.600 18.00 N/A 10 0.00% 100.00% 1.97e+06 4.69e+06 0.42 / 0.22 190.7% Kin-Z (shms) REF-VAC -5.600 18.00 N/A 6 0.00% 100.00% 7.02e+05 3.54e+06 0.20 / 0.22 90.0% Kin-Z (shms) C-OPTICS -5.600 18.00 N/A 7 0.00% 100.00% 7.37e+05 1.39e+06 0.53 / 0.50 105.7% Kin-Z (shms) EMPTY -5.600 18.00 N/A 4 0.00% 100.00% 1.13e+05 9.58e+05 0.12 / 0.50 23.7%
Kin-Z-pos (shms) REF-HE3 5.600 18.00 N/A 0 0.00 / 0.22 0.0%
- The above table is also posted to the HCLog every shift with the subject "Recent SHMS and HMS run list".
- You can use the
Hall C Run List Summarieslink under the HCLog Useful Links sidebar on the right as a shortcut.
- The runtimes and estimated yields are based on Rate Estimate Updates (19 Mar 2020) by Wolfgang
- (NOTE: Ignore the primed kinematics in the file, they are not relevant anymore.)
Special Runs
Miscelaneous Calibrations
BCM Calibration-- Complete https://logbooks.jlab.org/entry/3824242Beam Energy Measurement-- Completed (10390 +- 4 MeV/c) https://logbooks.jlab.org/entry/3830781Bulls Eye Scan-- Done for A1n (do we want a repeat?)- Positive polarity (CSB) running (See notes below)
- Optics Running (Optional, See notes below)
- 1-pass running (See dedicated section below)
Optics Running (OPTIONAL)
- We took all of the critical Optics data we need back in March. (These have been analyzed.)
- [OPTIONAL] Additional Optics running
- Kin-X (SHMS) P = -7.500, Th = 11.00 (Sieve, No-Sieve) (6--8 hours)
- Kin-B (HMS) P = -4.200, Th = 16.40 (No-Sieve) (1 hour)
- NOTE: (We would take the above runs together and likely just take both Sieve
and No-Sieve in each arm.
Notes for Near Term Running
NOTE: This will be updated frequently
Positron Running (Charge Sym BG study)
- Simona showed a nice plot from the Hall C F2 running of their CSB correction at 21deg vs E'.
That indicates the e+:e- correction is indeed quite small (she'll send out the F2 data to the group) - That argues that all we need to measure are rates -- much simpler/faster.
- Mike Nycz provided some data from Marathon as well
- For rates only, it looks like it would be better to use the SHMS instead since its polarity can be reversed remotely
- We will juggle the positive running in Kin-Z with taking longitudinal data on Thu/Fri (Aug 20, 21) - Warning (Aug 20): The positive SHMS running seems to have impacted the target much more than anticipated. - Took positive SHMS running for Kin-X (+7.500 11.00deg) on OWL, Aug 20 -- Done - WANT positive SHMS running for Kin-Z (+5.600 18.00deg) -- TBD
Longitudinal Running
- Every kinematic requires roughly 10--12 hours of longitudinal running
- We will attempt some longitudinal running for this kinematic pair (Kin-A, Kin-X) starting
Thursday swing following the Moller (Aug 20)
- We will have to come back to these kinematics next week!
Reference Cell Running
- Every kinematic requires roughly 12 hours of Reference cell running
- REF-Hydrogen, REF-Nitrogen, REF-Vacuum, REF-He3
- NOTE: Make He3 the last ref-cell fill before a major change, so we 're-use' the He3
in the next setting.
Remaining Reference Cell running at current settings (Updated 4pm, Aug 20)
Kin-A Kin-C Kin-X - REF-Hydrogen 97% 0%* 92% (collected) - REF-Nitrogen 80% 76%* 154% (collected) - REF-Vacuum 83% --%* 86% (collected) - REF-He3 202% --% 155% (collected)
Pol 3-He Cell Changes
See also: Production Target Cell Information
- Replaced Austin with Briana on Aug 21--24
- Tommy being remounted; will be next available cell
- Butterball will be prepped next
- NOTE: Butterball is quite short (21mm short vs. 3mm tolerance; associated issues must be addressed)
1-pass Running • Starting Mon, Aug. 31; Ending Thu, Sep 3
- Pass change deferred for 8am Monday, Aug 31 - See D2n_Run_Plan_2020#1-pass_Running below for details
5-pass Production Procedure
- SHMS and HMS runs are independent, but are run in pairs that should reflect similar rates (when possible)
- Run time for each of the 3 kinematic pairs is roughly 125 PAC hours, ~10 calendar days/pair
- Minimize the number of NMR measurements to preserve target polarization
- This generally means minimizing target direction changes, since each change usually imposes an 'as-is' NMR, and then a post-rotation NMR.
- General considerations
- Flip IHWP every 4--8 hours (coordinate with Hall A) - Ensure Charge Asym Feedback is running/working (watch the stripcharts and coordinate with Hall A) - Take NMR meas. every ~5 hours - Schedule a Moller run roughly every week - Target spin rotations/tests should be done immediately prior to the Moller so target has time to spin back up
- Reference cell runs needed for all Kinematics (nominal 2--4 hours per kinematic)
- Reference cell Nitrogen [135 psig] (Insert when we need time to spin up Polarized Cell) - Reference cell Hydrogen [135 psig] (Insert when we need time to spin up Polarized Cell) - Reference cell Vacuum [0 Torr] (Insert when we need time to spin up Polarized Cell) - Reference cell He3 [135 psig] (NOTE: Make best use of He3 by running this last in first kinematic, then first in next kinematic!)
- Polarized 3He Target • Transverse (90, 270) • Total run time 8--10 days
- Flip target spin after 3--4 days - Run 3--4 more days with the opposite target spin
- Polarized 3He Target • Longitudinal (0, 180) • Total run time ~1--2 days
- Flip IHWP at 1/2 way into each run block (~4 hours if possible) - ~11 hours @ 0deg - ~11 hours @ 180deg
1-pass Running
Still cleaning this up, but all the major items should be represented here.
- Pass change to 1-pass
- 8am Monday, August 31
- Pass change to 5-pass
- 8am Thursday, September 3
- That is a nominal 64 hours (assuming 8 hours for pass change)
A1n 1-pass running notes
- https://hallcweb.jlab.org/wiki/index.php/1-pass_calibration_for_A1n_(Jan_2020)
- https://hallcweb.jlab.org/wiki/index.php/1-pass_calibration_for_A1n
- Elastic Run Summaries from A1n period: SHMS, HMS
Verify the following before 1-pass period
- Is it worth taking a Moller measurement at 1-pass (Dave G., et al)
- Is there any reason we must run with SHMS at 8.5 degrees?
- 8.5 degrees is tricky to get to (requires experts in-hall to rotate so tight to beamline)
- May require experts in Hall to rotate spectrometer away from beamline too (downtime for access)
- 11.0 degrees has better FoM for asyms
- A1n had the SHMS at 11.7deg -- why that particular angle?
- Ensure the 1-pass analysis scripts are ready (Scott, Chao); Chao reports that is ready to go now
- Review the 'Scint. bar configuration' notes below
Notes on 1-pass elastic scripts [click me to expand]
[Notes from Chao] Subject: RE: Online Plots for 1-Pass Elastic Experiment
For performance I have temporarily commented the elastic analysis in the scripts:
in "hallc_online/analysis/hcfull":
script_file = '../hallc_online/analysis/elastic/el_asym_{}.cxx'.format(args.command.lower())
script_args='{},{},\"{}\"'.format(args.run, -1, args.mode)
analysis_cmd = "root -b -q '{}+({})'".format(script_file, script_args)
- os.system(analysis_cmd) <- this line
in "hallc_online/util/post_plots_to_logbook": -a "${ODIR}"/MON_OUTPUT/ANLYSIS_HISTOS/${2}/PID_variables2.png
# -a "${ODIR}"/MON_OUTPUT/ANLYSIS_HISTOS/${2}/elastic1.png <- this line
# -a "${ODIR}"/MON_OUTPUT/ANLYSIS_HISTOS/${2}/elastic2.png <- this line
Please uncomment them for the auto-posting
The elastic asymmetry runs were determined with the momentum setting (-p) and angle (-a) setting in "hallc_online/bin/make_elastic_asym_plots":
python3 analysis/elastic/asym_elastic.py HMS -p 2.17 -a 11.7 -t 0.1 --estimate=0.0503 --factor-qe=0.65 --date-start=2020-08-01
python3 analysis/elastic/asym_elastic.py SHMS -p 2.17 -a 8.5 -t 0.1 --estimate=0.026 --factor-qe=0.80 --date-start=2020-08-01
here "--date-start" is used to separate d2n elastic runs from a1n elastic runs.
The scripts for elastic runs are ready, and I have added them for the auto-posting.
There will be two elastic plots in the analysis post for each run, showing the elastic cuts.
These posted plots are generated by the scripts
"~/polhe3/production/hallc_online/analysis/elastic/el_asym_(s)hms.cxx"
At the end of each shift, the summary post (recent SHMS and HMS run list) will show the total asymmetry from all the elastic runs.
Currently I am using the A1n elastic settings, please let me know if any changes are needed.
Or you can change the settings in "~/polhe3/production/hallc_online/bin/make_elastic_asym_plots", as:
python3 analysis/elastic/asym_elastic.py HMS -p 2.17 -a 11.7 -t 0.1 --estimate=0.0503 --factor-qe=0.65 --date-start=2020-08-01
python3 analysis/elastic/asym_elastic.py SHMS -p 2.17 -a 8.5 -t 0.1 --estimate=0.026 --factor-qe=0.80 --date-start=2020-08-01
Please check the following instruction for the script's arguments:
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
Necessary Prep work during Hall Controlled Access (schedule with RadCon in advance)
- Install collimators (JP, RadCon) [2]
- Check on EPR photo-diode status, likely replace it (RadCon)
- Ensure fast raster is reconfigured correctly (Expert: Jones, Gunning)
- "Have MCC click on the button on the Expert page for 1 coil (instead of 2 coils). Ensure "gbeam_pass1_jan2020.param" is used for analysis"
SHMS/HMS scintillator bars settings for He3 Elastic and QE runs
A1n paddle studies for 3He elastics in SHMS, and QE in HMS
HMS Paddle Config Optimized for QE Measurement
(From first_epics_HV.results https://logbooks.jlab.org/entry/3762316)
- Turn OFF paddles 01 through 09 in h1x (both sides: '+' and '-')
- Turn OFF paddles 01 through 09 in h2x (both sides: '+' and '-')
- Only this set of HMS h1x and h2x paddles should be ON
h1x10(+) through h1x16(+)
h1x10(-) through h1x16(-)
h2x10(+) through h2x16(+)
h2x10(-) through h2x16(-)
- Keep all y paddles ON (unchanged)
- The HMS_all HV GUI after this action should be consistent with the A1n QE settings at https://logbooks.jlab.org/entry/3762307
SHMS Paddle Configuration Optimized for He3 Elastic Measurement
(From first_epics_HV.results https://logbooks.jlab.org/entry/3762329)
- Turn OFF all 1x and 2x paddles ((both sides: '+' and '-') EXCEPT 07, 08 in 1x, and 07, 08, 09 in 2x
- Only this set of s1x and s2x channels should be ON
s1x07+(L) s1x07-(R) s1x08+(L) s1x08-(R) s2x07+(L) s2x07-(R) s2x08+(L) s2x08-(R) s2x09+(L) s2x09-(R)
- Keep all y paddles ON (unchanged)
HMS Paddle Optimization for 3He Elastics Measurement
TBD
Run Plan for 1-pass
- Detailed plans heavily lean on excellent notes from A1n period
Moller Measurement (4--8 hours; Must or Like?)
My inclination is to skip the Moller at 1-pass (Brad)
- Notes from Dave Gaskell
If we don't change the Wien angle for 1 pass running, Hall C should receive 97.5% of maximum polarization (which is about 87.5% now, so Hall C would get 85.3%). At 1 pass and close to maximum polarization, we are very insensitive to absolute beam energy and Wien angle. Even incorporating a 3 degree uncertainty in the Wien angle would only change the polarization about 1.3%. Few MeV differences in the beam energy, much less. Anyway - I don't think there's much risk in skipping the 1 pass Moller measurement in Hall C. A super-conservative estimate of the polarization uncertainty would be 4%. Conservative: 3%.
- 5-pass Hall C Wien settings from recent Moller: https://logbooks.jlab.org/entry/3820002
Polarized 3He Cell Density Measurement (1 hour plus time for setup)
Goals - To determine 3He and N2 density in cell Briana Setup - Beam Current: 10uA, raster always ON (4mm diameter) - Target: Polarized 3He Cell "Briana", polarized in 180 deg.
Spectrometer Setup - HMS setting: 11.7 deg, -2.1483 GeV/c (electron 3He elastic) for density of "Briana". - SHMS setting: 8.5 deg, -2.12860 GeV/c (electron QE) for collimator check and asymmetry. - HMS Detectors: Turn OFF HMS h1x01 thru h1x09 and h2x01 thru h2x09, see hclog 3755438 - SHMS Detectors: follow QE/el measurement setup below.
Procedure - Set spectrometers at the required settings, target at the Polarized 3He Cell position; - Check that scintillator bars in HMS and SHMS are as specified above. - Ask MCC for 10 uA raster ON (4mm dia). Adjust prescale factor to limit the DAQ rate to 3.5-4kHz. (Do NOT drop below 10uA. If rates are low, increase beam current but do not exceed 30 uA.) - Take two 30-min runs at this setting. (see below)
Things to watch for - We need at least 10k events each from 3He elastic and N2 elastic peaks. - Run Chao's script to pull out # of events for 3He elastic and N2 elastic and post in hclog; - If we don't expect to achieve 10k events within one hour, contact RC. - For SHMS, post ytar(ztar) histogram in hclog. This shows effects of the new collimator. - Chao will run analysis remotely to extract 3He elastic fraction on SHMS.
Polarized 3He Delta Transverse Asymmetry (4-8hr)
Goals - To determine the sign of transverse asymmetry of Delta resonance on HMS and SHMS. - On SHMS we will also take QE events which help to determine sign of transverse asymmetry. - Experts must watch EDTM rate (Brad or Sylvester)
Setup - Beam Current: 5-30uA, raster always ON (4mm diameter) - Beam IHWP: should be switched half-way - Target: Polarized 3He Cell - Detectors: All scintillator bars ON. - Parity check: Inform Hall A to make sure they set the Qasym feedback cutoff at 2uA. - Spectrometer Setup (with HMS 11.7, SHMS 8.5 deg) - HMS setting: 11.7 deg, -1.75830 GeV/c (electron W=1.232) - SHMS setting: 8.5 deg, -1.79736 GeV/c (electron W=1.232)
Pol 3He Target Setup (TO and Target Expert) - Target spin direction: pointing either beam-left or beam-right viewing downstream. - See Target Field Runplan for coil currents settings (note: in this spreadsheet, target spin 90 is beam-left and 270 is beam-right, i.e. opposite of target field controller screen).
Procedure - Set target at Polarized 3He Cell position, spin pointing either beam-left or beam-right. - Check and make sure all scintillator HVs are ON (both HMS and SHMS). - Perform one set of polarimetry (NMR, EPR if possible) measurements before taking data. - Ask for 5uA raster ON, check rates and set prescale factors (Save them if changed!). - Goal is (3.5-4)kHz DAQ rates on both HMS, SHMS. - If rates too low (unlikely), can increase current to reach the desired rates but do not exceed 30uA.
- If we have 4 hours of beam time:
- Take two 60-minute (beam ON at least 30 min each) runs. - Switch beam IHWP position (need to inform other halls in advance). Either from IN to OUT or from OUT to IN. - Take two 60-minute (beam ON at least 30 min each) runs. - Perform one set of polarimetry (NMR, EPR if possible) measurements.
- If we have 8 hours of beam time:
- Take four 60-minute (beam ON at least 30 min each) runs. - Perform one NMR measurement. Verify target is still polarized. - Switch beam IHWP position (need to inform other halls in advance). Either from IN to OUT or from OUT to IN. - Take four 60-minute (beam ON at least 30 min each) runs. - Perform one set of polarimetry (NMR, EPR if possible) measurements.
Things to watch online - Apply y or z cuts to isolate events scattered from 3He gas. - Apply 1.1<W<1.35 GeV cut to isolate the Delta resonance. - Run online script to ensure we see physics asymmetry. Plot asym vs. W and nu. - HMS and SHMS should see opposite signs of asymmetries (but not the same magnitudes).
- Expected asymmetries for Delta(1232): Ameas=0.67% at 11.7deg and 0.46% at 8.5 deg if Pt=50%, Pb=85%, N2 dilution 0.92. - Expected asymmetries for QE are given in hclog 3759756 (ignore Aperp2, SHMS will see Aperp always, up to a sign) - Expected rate: 5kHz at 1uA, about 10% (5% w/o collimators) would be Delta(1232) from 3He gas for HMS (SHMS), see hclog 3758839 analysis of 11.7 deg data taken previously. - Counts needed to reach 10% on Ameas relative: 2.2M on HMS or 4.7M on SHMS. If Pt below 50%, scaleup by (50%/Pt)^2. - Expected time to reach 10% on Ameas relative: 1.6 pac hours for HMS, 5.6 pac hours for SHMS (with all paddles on and w/o collimators. Adding target collimators on the SHMS side will help significantly).
Polarized 3He Runs, 3He elastic and QE longitudinal Asymmetries (8-16 hours)
NOTE: SHMS setting should have better FoM at 11 degrees,
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: 5-30uA, raster always ON 4(mm diameter) - Target: Polarized 3He Cell - Target spin direction: 180 deg - See Target Field Runplan for coil currents settings. - Parity check: Inform Hall A prior to taking data to make sure they set the Qasym feedback cutoff at 2uA. - Time: total 8-16 hours of data taking, flip beam IHWP every 4 hours. Do target NMR every two hours and 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) - SHMS setting: 8.5 deg, -2.12860 GeV/c (electron QE setting, butfocus on 3He elastic events) - HMS Detectors: turn off paddles 1-6 on 1X plane and paddles 1-6 on 2X plane, see hclog 3756736. - SHMS Detectors: keep only paddles 7,8 of 1X plane, and paddles 7,8,9 of 2X ON, all others off; see hclog 3760238 - SHMS (continued): Also suggest for 1Y keep only 7 on, all others off, although this will depends on how well the collimators works.
Procedure - Set target at the Polarized 3He Cell position, spin 180 deg. - Verify HMS scintillator bar status the same as suggested above; - Verify SHMS scintillator bar status the same as suggested above; - Perform one full set of polarimetry (NMR, EPR if possible) measurements before taking data. - 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 5uA. - If rates too low (unlikely), increase beam current but do not exceed 30uA.
- Take 4 60-minute runs (assuming 50% beam efficiency). Perform NMR every 2 hours.
- Call MCC and ask beam IHWP to be inserted (or taken out). Need to inform other halls prior to the switch. - Take 8 60-minute runs (assuming 50% beam efficiency). Perform NMR every 2 hours.
- Call MCC and ask beam IHWP to be inserted (or taken out). Need to inform other halls prior to the switch. - Take 4 60-minute runs (assuming 50% beam efficiency). Perform NMR every 2 hours.
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.
3He Reference Cell Runs (N2 and 3He Pressure Curves, False Asymmetries) (5hrs ideal, 3 hrs min)
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: 10-30uA, raster always ON (4mm diameter). Do not drop currents below 10uA. - 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.
Procedure - Set spectrometers at the required settings, target at the Reference Cell position; - Make sure the correct two scintillator bars are ON; - Reference cell should already be filled with 135 psi He3 (**IF this will work**)
- Ask for 10 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.
- Reference cell should already be filled with 135 psi He3 - Next proceed to 3He pressure curve measurement. For each setting, follow rate/prescaling criteria above. For each run, record the pressure reading in the Start_Run and End_Run entries. - Start with cell at 135 psig with 3He gas, take one 20-min run. - Drop pres. the cell to 105 psig with 3He gas, take one 20-min run. - Drop pres. the cell to 75 psig atm with 3He gas, take one 20-min run. - Drop pres. the cell to 45 psig with 3He gas, take one 20-min run. - Drop pres. the cell to 15 psig with 3He gas, take one 20-min run. - Drop pres. the cell to 1 psig with 3He gas, take one 20-min run. - Evacuate cell to vacuum and take one 20-minute run.
- Fill Reference Cell with N2 gas to 105 psig. (8 atm; Why not 135 psig?) - Keep the same beam current as above, check trigger rate. 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.
- Take two 45-minute runs. Record the pressure reading in the Start_Run and End_Run entries. - Ask MCC to change the beam IHWP plate status, for example from IN to OUT or from OUT to IN. - Take two 45-minute run. Record the pressure reading in the Start_Run and End_Run entries. - Next proceed to remaining pressure settings. For each setting, follow rate/prescaling criteria above. For each run, record the pressure reading in the Start_Run and End_Run entries. - Pump/vent the cell to 45 psig, take one 20-minute run. - Pump/vent the cell to 15 psig, take one 20-minute run. - Pump/vent the cell (slowly) to 1 psig, take one 20-minute run. - Pump/vent the cell (slowly) to 380 Torr, take one 20-minute run.
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.
Reference Cell Hydrogen (H2) Cross Section (1--2 hours)
Goals - To measure hydrogen elastic cross section as a cross check of data quality - To measure backgrounds from glass cell and beamline windows (Reference-VAC)
Setup - Beam Current: up to 30uA and DAQ rate-limited, raster always ON (4mm diameter) - Target: Reference Cell: vacuum and filled with H2 to 135 psig - Detectors: All scintillator bars on
Procedure - Set spectrometers at the required settings, target at the Reference Cell position; - Pump out 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. - Take one 20-minute run, make sure there are no less than 10,000 events for each of HMS and SHMS. - Record the pressure in End_Run entries.
- 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. - Take one 20-minute run, 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 reading in the Start_Run and End_Run entries.
Things to watch online - Ensure all scintillator bars are ON - For 10atm H2 filled cell, apply ytar or ztar cuts to isolate events scattered from H2 gas (We do not want events from the glass windows!), and apply W cuts to select only H2 elastic. Note the elastic peak is not at dp=0 because the spectrometers are set at 3He elastic. - Run online script to ensure we collect no less than 10,000 H2 elastic (with ytar or ztar and W cuts) for each of HMS and SHMS
Polarized 3He Elastic Longitudinal Asymmetry (8hrs -- end of 1-pass running)
- Pol He3 Elastic group's simulations suggest that we start with the SHMS at 11deg (instead of 8.5deg).
- That shows an equal or better FoM, and we are less exposed to the high-rate backgrounds, and will /not/ require extra staff support and time to rotate SHMS to that angle.
- Collect our baseline Pol He3 Elastic asym at 11 deg, then continue with the Pol He3 Elastic group's run plan (stepping the SHMS out in angle) until we run out of beam time.
- HMS would be parked at around 18.5 degrees for the bulk of the 3He Elastic Asym running
- Pol He3 Elastic group's simulations suggest that we start with the SHMS at 11deg (instead of 8.5deg).
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: 10-30uA, raster always ON (4mm diameter) - Target: Polarized 3He Cell, Reference Cell - Target spin direction: 0-deg, 180-deg - See Target Field Runplan for coil currents settings. - Detectors: We will need to keep only 2 scintillator bars ON to accept 3He elastic and limit quasi-elastic scattering events. - 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, 2 hours each at target spin/beam IHWP =0/IN,0/OUT,180/IN,180/OUT. If beam time is less than 8 hours, reduce time at each spin/IHWP setting. 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. - 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 5 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 (3.5-4)kHz 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 hours of beam on target for inital (11.0 deg) point; flip IHWP at half-way mark - If pNMR is well understood, and if 0 degree target performance is well understood, then it would be good to take runs with target at 0deg as well
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).
