Commissioning Plan 2017

HMS/SHMS Magnet Cycling Procedures

HMS

• ALWAYS set DIPOLE by NMR coming DOWN from 900 A
• Set QUADS by initially setting to a current of 200 A above the set currents (or the maximum current of 1100 A for Q1 if set current + 200 > 1100), and then coming DOWN.

SHMS

• General principal: A magnet will be “on loop” if it has been taken to Imax (11 GeV) and stays on the descending branch of the hysteresis loop. Otherwise it is "off loop"
• Cycle procedure: Go to Imax and descend to target current.
• Action logic table

Status/Action	Magnet status is “on loop”	Magnet status is “off loop”
Increasing abs(p) at this polarity	Descend to target current	Cycle
Decreasing abs(p) at this polarity	Cycle	Cycle
Changing polarity	Set to 0 current, switch polarity, cycle	Set to 0 current, switch polarity, cycle

Beam energy of 2.2 GeV

Initial conditions

• HMS/SHMS angle surveys.
• Beamline BPM and Harp surveys. Check offsets in MCC database.
• HMS/SHMS Conditions:

HMS/SHMS collimator:	PION , COLLIMATOR
HMS/SHMS trigger:	SCIN 3/4, SCIN 3/4
HMS angle/momentum	25 deg, -1.6 GeV/c
SHMS angle/momentum	25 deg, -1.6 GeV/c

Beam Checkout with Superharps and Beam Position Monitors

• Experts: Mark Jones
• Expected time: 3 hours
• Initial measurement of beam spot size. Followed by calibration of girder BPMs
• Conditions:

beam current:	5 μA
fast raster:	off
target:	none

• Ask MCC to do superharp scan with superharps IHA3H07A and IHA3H07B and put entry in ELOG. Record the 3 BPMs positions (3H07A,3H07B,3H07C) during scan.
  • Want beam spot with sigma_x and sigma_y below 200 um ( beam pass 1-4) and below 300 um for beam pass 5.
    • If beam spot size is too large contact Run Coordinator to decide how to proceed.
    • If good beam spot size, then this will be first point in beam alignment
  • Determine the BPM offset from measure harp position
  • Are X (Y) from IHA3H07A and IHA3H07B at zero within 300 um?
    • If not ask MCC to center using the BPMs as relative guide.
• Calibrate Girder BPMs to the girder harps at 5uA
  • Ask MCC to move the beam horizontally by ±2 mm, and record at each setting both superharps and the three BPM's, both from MEDM/TCL and from the data stream after short runs.
  • Ask MCC to move the beam vertically by ±2 mm, and record at each setting both superharps and the three BPM's, both from MEDM/TCL and from the data stream after short runs.
• Calibrate Girder BPMs to the girder harps at 30uA
  • Ask MCC to move the beam horizontally by ±2 mm, and record at each setting both superharps and the three BPM's, both from MEDM/TCL and from the data stream after short runs.
  • Ask MCC to move the beam vertically by ±2 mm, and record at each setting both superharps and the three BPM's, both from MEDM/TCL and from the data stream after short runs.
• Calibrate Girder BPMs to the girder harps at 60uA
  • Ask MCC to move the beam horizontally by ±2 mm, and record at each setting both superharps and the three BPM's, both from MEDM/TCL and from the data stream after short runs.
  • Ask MCC to move the beam vertically by ±2 mm, and record at each setting both superharps and the three BPM's, both from MEDM/TCL and from the data stream after short runs.
• Check raster size use harp at 10uA
  • Take harp scans with a fast raster with varying size, say 2 by 2, 3 by 3, and 4 by 4 mm2.

Center beam on C-hole target

• Experts:
• Expected time: 1 hour
• Goal: Center beam on carbon hole target
• Conditions:

beam current:	5 μA
fast raster:	3x3mm
target:	carbon hole
HMS/SHMS collimator:	PION , COLLIMATOR
HMS/SHMS trigger:	SCIN 3/4, SCIN 3/4
HMS angle/momentum	25 deg, -1.6 GeV/c
SHMS angle/momentum	25 deg, -1.6 GeV/c

• Take singles data in both arms. Analyze using the raster script.
• Once beam centered on target, then can check the "halo" target.
• Record Girder BPMs. Will use these beam positions until beam centering with HMS.

Initial HMS/SHMS Detector Checkout

• SHMS/HMS optics experts:
• HMS DC experts:
• Expected time: 1 hour
• Goal: Initial checkout of the HMS/SHMS detectors. Working well enough for carbon elastics data. Initial checkout of the SHMS/HMS tunes.
• Conditions:

beam current:	5-20 μA
fast raster:	off
target:	0.5% carbon
HMS/SHMS collimator:	PION , COLLIMATOR
HMS/SHMS trigger:	SCIN 3/4,SCIN 3/4
HMS angle/momentum	25 deg, -1.6 GeV/c
SHMS angle/momentum	25 deg, -1.6 GeV/c

• Need to have rough calibration of BCM1 and BCM2.
• First check trigger rates ( 4kHz at 20uA), background triggers rate
• Confirm the HMS DC tracking is working properly and efficiency is high.
• Compare HMS/SHMS focal plane plots to MC simulation.
• Adjust SHMS Q2 strength if needed.

BCM Calibration

• Experts: Dave Mack
• Expected time: ? hours
• Goal:
• Conditions:

beam current:	1-60 μA
fast raster:	off
target:	none

Beam Energy Measurement

• Experts: MCC,Mark Jones, Dave Mack
• Expected time: ? hours
• Goal: Measure beam energy for carbon elastics.
• Conditions:

beam current:	5uA
fast raster:	off
target:	none

• MCC procedure

Check SHMS/HMS Tune with sieve

• Experts:
• Expected time: ? hour
• Goal: Initial checkout of the HMS/SHMS detectors. Working well enough for carbon elastics data. Initial checkout of the SHMS/HMS tunes.
• Conditions:

beam current:	5-20 μA
fast raster:	off
target:	0.5% carbon
HMS/SHMS collimator:	SIEVE , CENTERED SIEVE
HMS/SHMS trigger:	SCIN 3/4,SCIN 3/4
HMS angle/momentum	25 deg, -1.6 GeV/c
SHMS angle/momentum	25 deg, -1.6 GeV/c

• Compare to MC plots.

Vertically center beam on HMS

• Experts:
• Expected time: ? hour
• Goal:
• Conditions:

beam current:	5-20 μA
fast raster:	off
target:	0.5% carbon
HMS/SHMS collimator:	SIEVE , CENTERED SIEVE
HMS/SHMS trigger:	SCIN 3/4,SCIN 3/4
HMS angle/momentum	25 deg, -1.6 GeV/c
SHMS angle/momentum	25 deg, -1.6 GeV/c

• Use the previous run, or if you are in the iteration process run at less than 10 μA current, use the Carbon optics target. Use a fast raster size of 1 by 1 mm2. The exact raster shape does not matter: the raster can even be off in this configuration. Take a short run (100K). Analyze and make an ntuple. Make the following plots: x vs y at the focal plane, xp vs yp at the target (you may have to use some Particle Id. and reconstruction cuts here!), and y at the target. You want to check the following: is the central leg of the ``spider" in x vs y at the focal plane straight? is the reconstructed y position close to y = 0? Is the central sieve slit hole close to (yp,xp) = (0,0)? If the xp position of the central sieve hole is close to 0, you probably are a bit off in vertical beam position after all, fix this. If you are far off (larger than 2 mr), check all your results carefully, did something go wrong in the vertical beam assignment? If the central leg of the ``spider" is close to vertical, you are close to having mid-plane symmetry for the spectrometer. You can vary the horizontal beam position a bit to check this. Note that the present quad alignment is such that the quad system is about 1 mm to the right of the line through the nominal pivot and the spectrometer angle, so the y position at the target can be a little bit negative, and the central leg of the spider can be slightly tilted. If the yp position of the central sieve hole is within 1 or 2 mr of the nominal zero position you are probably fine. The big uncertainty will be whether the targets are actually located at the nominal pivot (z = 0) position. If the target survey says otherwise, you expect (i) the central leg of the ``spider" not to be straight, (ii) the y reconstruction not to be perfect, and (iii) an offset in yp for the central sieve hole. If the three pieces of information are pretty much consistent with the survey assume you are done (note: the HMS sieve is at a distance of 1.66 meter of the target). You can consider checking this by using a hole target, or by rotating the spectrometer to a larger angle, and verifying that indeed things are consistent.

Verify Quadrupole Settings SHMS

• Experts:
• Expected time: ? hour
• Goal:
• Conditions:

beam current:	5-20 μA
fast raster:	off
target:	0.5% carbon
HMS/SHMS collimator:	SIEVE , CENTERED SIEVE
HMS/SHMS trigger:	SCIN 3/4,SCIN 3/4
HMS angle/momentum	25 deg, -1.6 GeV/c
SHMS angle/momentum	25 deg, -1.6 GeV/c

• Now that we know the beam-interaction point, we start looking at the SHMS. Use the Carbon optics target and beam raster pattern as before, and the collimator (no sieve slit needed yet). For SHMS, the point-to-point optics at the focal plane will look skewed as the horizontal bend magnet will ruin the regular symmetry of the spectrometer optics, so x and y will be coupled. Thus, for the SHMS you may have to compare simulated focal plane patterns with measurements to be able to judge if quadrupole fields differ from expected although you can do much with just looking at the focal plane pattern. First verify that we have obtained a point-to-point focus with the extrapolated quadrupole settings, by looking at plots of hsxfp vs. hsyfp. The SHMS should have a “tilted” hour glass pattern for a point target source, with the waist of the hourglass at (0,0). If not, vary the quadrupole settings in small steps (try 0.2, 0.5 or 1% steps. Q2 is most sensitive and 0.2% steps should be sufficient for Q2 – the gradient of motion of the hourglass waist is roughly 2 cm per % Q2 change. For Q1 it is about -0.4 cm per % Q1 change), until the golden tune (this is defined as the SHMS quadrupole settings that most closely reproduces the simulated sieve slit patterns at the focal plane) is obtained. Measure a spectrum with high statistics (>>100K) to use for later off-line checks and to continue the second phase of detector checkout – this is needed before starting the sieve slit runs. Check the time-to-distance maps, align the wire chamber positions in software and enable linked stub fitting, check the detector positions, check the timing and calibration constants (shower counter gains, pedestals, timing offsets, pulse height corrections, attenuation lengths, efficiencies, position dependencies). Optimize tracking properties. Make sure that <math>\Theta</math> and <math>\Phi</math> spectra are wide as expected. Construct <math>x</math>, <math>y</math>, <math>\Theta</math>, and <math>\Phi</math> spectra at the nominal focal plane. Does everything look reasonable? Check tracking with one wire chamber set against tracking with two wire chamber sets. Reconstruct target quantities.
• You can also use these plots to help guide the setting of the quadrupoles.

Establish Initial SHMS Tune

• Experts:
• Expected time: ? hour
• Goal:
• Conditions:

beam current:	5-20 μA
fast raster:	off
target:	0.5% carbon
HMS/SHMS collimator:	SIEVE , CENTERED SIEVE
HMS/SHMS trigger:	SCIN 3/4,SCIN 3/4
HMS angle/momentum	25 deg, -1.6 GeV/c
SHMS angle/momentum	25 deg, -1.6 GeV/c

• Use the SHMS sieve slit with the middle vertical column centered in combination with the Carbon optics target. Use a current of less than 20 μA. Preferentially, the fast raster should be off for this series of measurements. However, a small fast raster size of 1 by 1 mm2 should also work. Measure a short Carbon spectrum of perhaps 100K events. Produce an ntuple, and do the following: make a spectrum of x vs y at the nominal focal plane. What you should see is a tilted ``spider" with 9 legs. The center of the spider/hourglass should be at (x,y) = 0 if everything went right. If not, check the beam interaction point and check the quadrupole magnet settings. Because the HB magnet destroys the mid-plane symmetry of the SHMS, you likely will need to compare simulated focal plane patterns with measurements to be able to judge if quadrupole fields are o.k. If you do see a difference you can try to change the quadrupole settings by say 0.1% and measure a new run and produce an ntuple to compare. If the patterns look similar we are done with establishing the Standard SHMS tune beyond the dispersion.

Tune SHMS with Carbon Elastic

• Experts:
• Expected time: ? hour
• Goal:
• Conditions:

beam current:	5-20 μA
fast raster:	off
target:	0.5% carbon
HMS/SHMS collimator:	SIEVE , CENTERED SIEVE
HMS/SHMS trigger:	SCIN 3/4, SCIN 3/4
HMS angle/momentum	12. deg, 2.2 GeV/c
SHMS angle/momentum	7.5 deg, 2.1 GeV/c

• Verify beam centered

Dispersion Calibration

• Experts:
• Expected time: ? hour
• Goal:
• Conditions:

beam current:	5-20 μA
fast raster:	off
target:	0.5% carbon
HMS/SHMS collimator:	PION , COLLIMATOR
HMS/SHMS trigger:	SCIN 3/4, SCIN 3/4
HMS angle/momentum	12. deg, 2.2 GeV/c
SHMS angle/momentum	7.5 deg, 2.1 GeV/c

• Install the sieve slit. Shift the elastic peak of Carbon across the focal plane by making 4% changes in the momentum setting (from +25 to -15% going down). Determine the dispersion matrix elements. Verify occasionally that the beam is centered.

Get X and Y Magnifications: Beam Sweep

• Use the central momentum setting, the sieve slit, and the thin Carbon target. Simulate a rastered beam by moving the beam up and down, left and right by a few mm (as much as we can have, but probably 2-3 mm suffices). Determine the influence on aberrative matrix elements.

Sieve Slit Measurements with C Optics “Extended” Target

• Lower the central momentum setting of SHMS to -1.2 GeV/c again. Put the sieve slit in. First verify that the beam is centered on the BeO target. Now we need to mimic an extended target. Presumably, this means measuring two separate runs, for
  • The triple optics target, with carbon foils at -10, 0 and +10 cm
  • The double optics target, with carbon foils at -5 and +5 cm

Take runs with at least 100 counts for each visible hole. Determine the angular matrix elements. As described, we simulate a 10 cm target length (as viewed by SHMS at a 30 degree scattering angle). Scan over +/- 1 cm (or whatever we used in an earlier step) to verify the effect of beam rastering on the angular matrix elements.

Target boiling study

• Experts:
• Expected time: hour
• Goal: Verify beam spot size
• Conditions:

beam current:	5-60 μA
fast raster:	1x1mm
target:	10cm LH2, 10cm LD2, 10cm dummy
HMS/SHMS collimator:	PION , COLLIMATOR
HMS/SHMS trigger:	SCIN 3/4, SCIN 3/4
HMS angle/momentum	25. deg, -1.6 GeV/c
SHMS angle/momentum	25. deg, -1.6 GeV/c

Beam energy of 6.4 GeV

Initial conditions

• HMS/SHMS Conditions:

HMS/SHMS collimator:	PION , COLLIMATOR
HMS/SHMS trigger:	SCIN 3/4, SCIN 3/4
HMS angle/momentum	15 deg, -3.0 GeV/c
SHMS angle/momentum	15 deg, -3.0 GeV/c

Superharp Scan

• Experts: Mark Jones
• Expected time: 1/2 hour
• Goal: Verify beam spot size
• Conditions:

beam current:	5 μA
fast raster:	off
target:	none

• Ask MCC to do superharp scan with superharps IHA3H07A and IHA3H07B and put entry in ELOG. Record the 3 BPMs positions (3H07A,3H07B,3H07C) during scan.
  • Want beam spot with sigma_x and sigma_y below 200 um ( beam pass 1-4) and below 300 um for beam pass 5.
• Verify Girder BPM position to Harp positions.

SHMS Tune Verification

• Experts:
• Expected time:
• Goal:
• Conditions:

beam current:	5-20 μA
fast raster:	off
target:	0.5% carbon
HMS/SHMS collimator:	PION , COLLIMATOR
HMS/SHMS trigger:	SCIN 3/4, SCIN 3/4
HMS angle/momentum	15. deg, -3.0 GeV/c
SHMS angle/momentum	15. deg, -3.0 GeV/c

Detailed Detector Checkout

• Experts:
• Expected time: ? hour
• Goal:
• Conditions:

beam current:	5-20 μA
fast raster:	off
target:	0.5% carbon
HMS/SHMS collimator:	SIEVE , CENTERED SIEVE
HMS/SHMS trigger:	SCIN 3/4,SCIN 3/4
HMS angle/momentum	25 deg, -1.6 GeV/c
SHMS angle/momentum	25 deg, -1.6 GeV/c

Wire Chamber

• SHMS Run plan:
• HMS Run plan:

Shower Counter Calibration Run

• SHMS Run plan:
• HMS Run plan:

Scintillator

• SHMS Run plan:
• HMS Run plan:

Cerenkov

• SHMS Heavy Gas Cherenkov: calibration plan
• HMS Run plan:

Aerogel

• SHMS Run plan:

Set Discriminator Thresholds for (P.Id.) Trigger

• Experts:
• Expected time:
• Goal:
• Conditions:

beam current:	5-20 μA
fast raster:	off
target:	0.5% carbon
HMS/SHMS collimator:	PION , COLLIMATOR
HMS/SHMS trigger:	SCIN 3/4, SCIN 3/4
HMS angle/momentum	15. deg, -3.0 GeV/c
SHMS angle/momentum	15. deg, -3.0 GeV/c

Defocused Run HMS and SHMS

• Experts:
• Expected time:
• Goal:
• Conditions:

beam current:	5-20 μA
fast raster:	off
target:	0.5% carbon
HMS/SHMS collimator:	PION , COLLIMATOR
HMS/SHMS trigger:	SCIN 3/4, SCIN 3/4
HMS angle/momentum	15. deg, -3.0 GeV/c
SHMS angle/momentum	15. deg, -3.0 GeV/c

Beam Energy Measurement

• Experts: MCC,Mark Jones, Dave Mack
• Expected time: ? hours
• Goal: Measure beam energy for carbon elastics.
• Conditions:

beam current:	5uA
fast raster:	off
target:	none

• MCC procedure

1H or 12C(eep) [3 hr]

• Experts:
• Expected time:
• Goal:
• Conditions:

beam current:	20-50 μA
fast raster:	1x1mm2
target:	3% carbon, 10cm LH2
HMS/SHMS collimator:	PION , COLLIMATOR
HMS/SHMS trigger:	SCIN 3/4, SCIN 3/4
HMS angle/momentum	27.5 deg, -3.609 GeV/c
SHMS angle/momentum	27.5 deg, +3.609 GeV/c

1H or 12C(e, e’ π) [2 hr]

• Experts:
• Expected time:
• Goal:
• Conditions:

beam current:	20-50 μA
fast raster:	1x1mm2
target:	3% carbon, 10cm LH2
HMS/SHMS collimator:	PION , COLLIMATOR
HMS/SHMS trigger:	SCIN 3/4, SCIN 3/4
HMS angle/momentum	16.8 deg, -3.8 GeV/c
SHMS angle/momentum	20.0 deg, +2.7 GeV/c

1H(e’K) and 1H(e, e’K) [3 hr]

• Experts:
• Expected time:
• Goal:
• Conditions:

beam current:	20-50 μA
fast raster:	1x1mm2
target:	10cm LH2
HMS/SHMS collimator:	PION , COLLIMATOR
HMS/SHMS trigger:	SCIN 3/4, SCIN 3/4
HMS angle/momentum	25.0 deg, -2.6 GeV/c
SHMS angle/momentum	15.0 deg, +3.6 GeV/c

Coincidence Checkout [16 hrs]

• Experts:
• Expected time:
• Goal:
• Conditions:

beam current:	20-50 μA
fast raster:	1x1mm2
target:	10cm LH2
HMS/SHMS collimator:	PION/SIEVE , COLLIMATOR/CENTERED SIEVE
HMS/SHMS trigger:	SCIN 3/4, SCIN 3/4
HMS angle/momentum	27.5 deg, -3.609 GeV/c
SHMS angle/momentum	27.5 deg, +3.609 GeV/c

• We will take a set of 1H(e,e’p) measurements to check the angle and dp/p offsets for the spectrometers. Use a current of 50 μA if possible. Rotate both HMS and SHMS to -27.5° again (or keep them there if already at that angle). Keep both HMS and SHMS at a central momentum of -3.609 GeV/c. First use the sieve slit on the SHMS side and the central Carbon optics target. Use the Particle Id. trigger, and measure about 2K singles in SHMS (that should take about one hour). Now install the 10 cm hydrogen target and measure about 2K singles in SHMS (that is again about one hour). Now take a coincidence spectrum in the same situation, again a measurement of about one hour. Remove the sieve slit on the SHMS side and use the large collimator. Measure a coincidence spectrum for one hour (rate should be 4 Hz, so this will get >10K statistics). Now install the sieve slit on the HMS side and measure another coincidence spectrum for a few hours (a few K statistics).

Elastic p(ep) Checkout

• Experts:
• Expected time:
• Goal:
• Conditions:

beam current:	20-50 μA
fast raster:	1x1mm2
target:	10cm LH2
HMS/SHMS collimator:	PION , COLLIMATOR
HMS/SHMS trigger:	SCIN 3/4, SCIN 3/4
HMS angle/momentum	27.5 deg, -3.609 GeV/c
SHMS angle/momentum	27.5 deg, +3.609 GeV/c

• Take runs to acquire roughly 10K events for HMS (use the large pion collimator!) at angles of 27.5°, 28.8°, 30.1°, 24.9°, and 26.2°. For SHMS at identical angles but also at angles of 31.8°, 33.5°, 35.2° and 23.2°. Roughly, at the central setting you need 45 minutes to acquire 10K statistics, and less at the lower angles, but perhaps 1.5 hour at 30.1°, and up to 5 hours at the largest SHMS angle of 35.2°.

Sieve slit measurement with C Optics “Extended” Target – Part I

• Experts:
• Expected time:
• Goal:
• Conditions:

beam current:	20-50 μA
fast raster:	off
target:	optics targets
HMS/SHMS collimator:	Sieve , Centered Sieve
HMS/SHMS trigger:	,
HMS angle/momentum	25. deg, -3.0 GeV/c
SHMS angle/momentum	25. deg, -3.0 GeV/c

Sieve slit measurement with C Optics “Extended” Target – Part II

• Experts:
• Expected time:
• Goal: Calibrate HMS ytgt, yptar and xptar for 10cm target.
• Conditions:

beam current:	20-50 μA
fast raster:	off
target:	optics targets
HMS/SHMS collimator:	Sieve , Centered Sieve
HMS/SHMS trigger:	,
HMS angle/momentum	50. deg, -2.0 GeV/c
SHMS angle/momentum	25. deg, -2.0 GeV/c

Check spectrometer pointing

• Experts:
• Expected time:
• Goal: Measure the HMS/SHMS spectrometer pointing
• Conditions:

beam current:	20-50 μA
fast raster:	off
target:	3% carbon
HMS/SHMS collimator:	Sieve, Centered sieve
HMS/SHMS trigger:	,
HMS angle/momentum	12.-60 deg, -3.0 GeV/c
SHMS angle/momentum	7.5-40 deg, -3.0 GeV/c

Beam energy of 8.8 GeV

Beam Energy Measurement

• Experts: MCC,Mark Jones, Dave Mack
• Expected time: ? hours
• Goal: Measure beam energy for carbon elastics.
• Conditions:

beam current:	5uA
fast raster:	off
target:	none

• MCC procedure

SHMS Tune Verification

• Experts:
• Expected time:
• Goal:
• Conditions:

beam current:	5-20 μA
fast raster:	off
target:	3% carbon
HMS/SHMS collimator:	PION , COLLIMATOR
HMS/SHMS trigger:	SCIN 3/4, SCIN 3/4
HMS angle/momentum
SHMS angle/momentum

Beam energy of 10.6 GeV

Beam Energy Measurement

• Experts: MCC,Mark Jones, Dave Mack
• Expected time: ? hours
• Goal: Measure beam energy for carbon elastics.
• Conditions:

beam current:	5uA
fast raster:	off
target:	none

• MCC procedure

SHMS Tune Verification

• Experts:
• Expected time:
• Goal:
• Conditions:

beam current:	5-20 μA
fast raster:	off
target:	3% carbon
HMS/SHMS collimator:	PION , COLLIMATOR
HMS/SHMS trigger:	SCIN 3/4, SCIN 3/4
HMS angle/momentum
SHMS angle/momentum