Spectrometer Optics 2pass 48p8d

Procedure without Sieve-slit

• Time estimate: 1 hour

* Take a run at the following kinematics without the sieve-slit collimator.
* Start with initial right HRS spectrometer tune with the SOS quad in place of right Q1.
* If you need to increase the spectrometer momentum setting, make sure you cycle Q2 and Q3 as per the cycling procedure.
* Electron rates assume 5 carbon foils or 2 Al dummy foils, 5 mSr acceptance, and 8% delta acceptance.
* A GMp expert will check the data quality and decide, if the right HRS tune needs to be adjusted to change the size of the acceptance.
* This process will be repeated until the spectrometer tune is satisfactory.

Target	Ebeam [GeV]	P0 [GeV/c]	Right Q1 Current [A]	θe [deg]	Q2 [GeV2]	W [GeV]	Rate [Hz] at 20 μA	minutes for 50k events at 20 μA
Optics	2.301	0.75	153.36	48.74	1.18	1.617	70.5	12
4 cm Dummy	2.301	0.75	153.36	48.74	1.18	1.617	37.4	22

Procedure with Sieve-slit

• Time estimate: 11 hours

* Trained personnel will be required to install the 1-inch tungsten sieve-slit collimator onto the front face of the HRS.
* Take a sieve slit run with the multi-foil carbon target for the inelastic kinematics in the table.
* If you need to increase the spectrometer momentum setting, make sure you cycle Q2 and Q3 as per the cycling procedure.
* Electron rates assume 5 carbon foils, only 37 out of 155 sieve holes per foil have events (~ 0.4 mSr acceptance), and 8% delta acceptance.
* Electron rates assume 2 aluminum foils, only 43 out of 155 sieve holes per foil have events (~ 0.47 mSr acceptance), and 8% delta acceptance.
* Electron rates assume 15 cm LH2 target, only 45 out of 155 sieve holes have events (~ 0.49 mSr acceptance), and 8% delta acceptance.

Target	Ebeam [GeV]	P0 [GeV/c]	Right Q1 Current [A]	θe [deg]	Q2 [GeV2]	W [GeV]	Rate [Hz] at 20 μA	hours at 20 μA
Optics	2.301	0.75	153.36	48.74	1.18	1.617	5.6	5 (for 100k events)
4 cm Dummy	2.301	0.75	153.36	48.74	1.18	1.617	3.5	4 (for 50k events)
15 cm LH2	2.301	0.75	153.36	48.74	1.18	1.617	20.0	1 (for 72k events)

Delta Scan with Proton Elastic

• Time estimate: 3-4 hours

* Trained personnel will be required to remove the 1-inch tungsten sieve-slit collimator from the front face of the HRS.
* Take a run with the 15 cm liquid hydrogen target for the elastic kinematics in the table.
* There will be a time lapse between settings until the right dipole reaches the desired momentum and is stable.
* If you need to increase the spectrometer momentum setting, make sure you cycle Q2 and Q3 as per the cycling procedure.
* Rate estimates only include elastic electrons and does not include inelastic rate or rate from the target endcaps. 
* The Q2 for these settings is 1.65 GeV2.

Ebeam (GeV)	k' (GeV)	θe (deg)	ΔP (%)	Rate [Hz] at 20 μA	minutes for 220k events at 20 μA
2.301	1.304	48.74	-4	176	21
2.301	1.279	48.74	-2	176	21
2.301	1.254	48.74	0	176	21
2.301	1.229	48.74	+2	176	21
2.301	1.203	48.74	+4	176	21

For each ΔP (%) setting, we want to take 3 runs with different Q1 currents:

For ΔP = -4%, we want the following Q1 currents:

1. -5%: 247.6764 A
2. -4%: 250.2835 A
3. +5%: 273.7476 A

For ΔP = -2%, we want the following Q1 currents:

1. -5%: 243.0224 A
2. -4%: 245.5805 A
3. +5%: 268.6037 A

For ΔP = 0%, we want the following Q1 currents:

1. -5%: 238.1660 A
2. -4%: 240.6730 A
3. +5%: 263.2361 A

For ΔP = +2%, we want the following Q1 currents:

1. -5%: 233.5119 A
2. -4%: 235.9699 A
3. +5%: 258.0921 A

For ΔP = +4%, we want the following Q1 currents:

1. -5%: 228.8579 A
2. -4%: 231.2669 A
3. +5%: 252.9482 A

Proton Elastic Run and Dummy Target Runs

• Go back to the ΔP = 0% elastic setting. Make sure the R-HRS P0 = 1.254 GeV and Q1 current = ? A (-4%)
• Take data with this setting for 1 hour

Ebeam (GeV)	k' (GeV)	θe (deg)	ΔP (%)	Rate [Hz] at 20 μA	minutes for 1M events at 20 μA
2.301	1.254	48.74	0	176	~ 105 mins

• Move the target to "Dummy"
• Take R-HRS run with same setting as previous step. We need at least 200 K events.