Commissioning

Survey
One survey before commissioning, for spectrometer angle at $20^\circ$, beamline girder and target.

Beam Tuning
Should be done through Compton Chicane;

OTR Measurement
One OTR (O??? Transition Radiation) measurement should be down right after beam tuning to obtain beam profile, 30 minutes;

Compton Set-up
Hopefully will take less than 8 hours;

BPM Calibration
Check BeO target position, one set of BPM/Harp measurement, 1 hour;

Charge asymmetry measurement
One should be done during commissioning, 1$\sim$2 hour(s);

Moller measurement
One should be done during commissioning, (first one) 3 hours;

Mott measurement
One should be done during commissioning, 1 hour;

Beam energy measurements - ep and ARC
One ep(2E-4) measurement, 1 hours;
One ARC (full, 2E-4) measurement, 1 hour;
ARC (bdl, 2E-3) measurement does not take extra beam time.

Detector Check-out
Should be done parasitically to the Compton setup, BPM, Moller, and beam energy measurement, use optics target;

Optics runs
With sieve slits in, $^{12}$C target, no raster, beam current 5$\mu A$, elastic, 5 minutes, or total number of events no less than 28K;
With sieve slits in, $^{12}$C target, no raster, beam current 5$\mu A$, quasi-elastic, 5 minutes, or total number of events no less than 20K;
With open collimator, $^{12}$C target, raster on, beam current 25$\mu A$, quasi-elastic, to check false asymmetry, 1 hour;

Acceptance runs
With open collimator, $^{12}$C target, raster on, beam current 25$\mu A$, do a momentum scan at elastic P$_0$, (1$\pm$0.02)P$_0$ and (1$\pm$0.04)P$_0$. Run 5 minutes for each point, or total number of events no less than 20K for each point;

Elastic Runs - for asymmetry and xsection
Polarized $^3$He target, parallel polarization, open collimator, raster on (4mm diameter), 13.3 hours, number of events in elastic peak no less than 1.8M, or total number of events no less than 2.5M. Polarization of the beam and the target needs to be reversed half way.

To reverse the polarization of the beam and the target, the following procedure needs to be followed:

• Take 2.5 hours data with target holding field at present direction (either 0$^\circ$ or 180$^\circ$, target half-wave plate(s) out;
• Call MCC to reverse the beam polarization, take 2.5 hours data;
• Rotate target holding field by 180$^\circ$, put target half-wave plate(s) in, take 2.5 hours data;
• Call MCC to reverse the beam polarization, take 2.5 hours data;

Delta Asymmetry Runs - determine sign of transverse asymmetry
Polarized $^3$He target, transverse asymmetry, open collimator, raster on (4mm diameter), 0.5 hour, number of events in delta resonance peak no less than 120K. (Polarization of the beam and the target needs to be reversed half way?)

Reference Cell Runs
The following runs should be with open collimator, raster on (4mm diameter), beam current 15$\mu A$.

For each pressure curve, should measure 4 points at 2.5, 5.0, 7.5 and 10.0 atm. To save $^3$He gas, $^3$He should be the last one to be measured.

Using N$_2$, measure pressure curve at elastic, For each pressure, take 2 minutes data or total number of events in elastic peak no less than 20K. Changing pressure takes 5 minutes so the total time will be 0.5 hour;
One run using N$_2$, measure false asymmetry at quasi-elastic; 20 minutes or total number of events in elastic peak no less than 25M;
(optional) One run using $^4$He, measure cross section at elastic, for normalization; 2 minutes or total number of events in elastic peak no less than 20K;
Using $^3$He, measure pressure curve at elastic, and check normalization; Take 8 minutes data at 2.5 atm, 4 minutes at 5.0 atm, 3 minutes at 7.5 atm and 2 minutes at 10.0 atm, respectively. Or for each pressure total number of events in elastic peak should be no less than 20K. Changing pressure takes 5 minutes so the total time will be 40 minutes;

Compton measurement
Will continuously run compton polarimeter during the experiment.

BCM calibration - optional
One BCM calibration takes 2 hours. However, one full BCM calibration has been done at the beginning of April (2 hours and Hall-A only, 100 $\mu A$). So we probablly do not need to do BCM calibration during E99-117.