Spectrometer Optics First pass 48p75d

If you have questions call Vince Sulkosky or Kalyan Allada, Numbers are on white board

Integration with LHRS plan

LHRS step	RHRS step	Approximate beam time	Goals	Status
L1 (sieve)	R1 (sieve)	3h	60 uA DIS with sieve slit on optics foils and LH2	L1 Completed R1 in progress
L2 (sieve)		1-2h	Elastic Delta Scan on LH2, 10 uA	Completed
	R2 (no sieve)	3-4h	Elastic Delta Scan on LH2, 60 uA	Completed
L3 (sieve)	R3 (no sieve)	1h	Elastic dummy	R3 completed L3 skipped
L4 (no sieve)	R4 (no sieve)	1h	LHRS: elastic LH2, 60 uA RHRS: DIS on single carbon and optics, 60 uA	R4 Completed L4 not started

See Left HRS Optics Run Plan

Step R1: Procedure with Sieve-slit

• Time estimate: 3 hours

* Trained personnel will be required to install the 1-inch tungsten sieve-slit collimator onto the front face of the HRS.
* If you need to increase the spectrometer momentum setting, make sure you cycle Q2 and Q3 as per the cycling procedure.
* Take sieve-slit runs with the multi-foil carbon target (optics) for the inelastic kinematics in the table.
* Electron rates assume 9 carbon foils, only 37 out of 155 sieve holes per foil have events (~ 0.41 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.
* Before moving on to the next target, a GMp expert will determine online how many good electron events have been collected. 

Target	Ebeam [GeV]	P0 [GeV/c]	RQ1	Raster	θe [deg]	Q2 [GeV2]	W [GeV]	Rate [Hz] at 60 μA	hours at 60 μA	Good Electrons
Optics	2.217	1.0	200.41	Off	48.75	1.51	1.287	14	2	100k events
15 cm LH2	2.217	1.0	200.41	2 x 2 mm2	48.75	1.51	1.287	40.0	1.0	144k events

Step R2: Delta Scan with Proton Elastic (without sieve slit)

• 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 runs with the 15 cm liquid hydrogen target for the elastic kinematics in the table.
* There will be about a 40 minute 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 rate from inelastic events or from the target endcaps. 
* The Q2 for these settings is 1.86 GeV2.

Ebeam (GeV)	k' (GeV)	RQ1	Raster	θe (deg)	ΔP (%)	Rate [Hz] at 60 μA	minutes at 60 μA	Good Electrons
2.217	1.277	255.93	2 x 2 mm2	48.75	-4	650	10	390k events
2.217	1.253	251.11	2 x 2 mm2	48.75	-2	650	10	390k events
2.217	1.228	246.10	2 x 2 mm2	48.75	0	650	20	780k events
2.217	1.204	241.29	2 x 2 mm2	48.75	+2	650	10	390k events
2.217	1.179	236.28	2 x 2 mm2	48.75	+4	650	10	390k events

Step R3: Dummy Target Runs

• Go back to the ΔP = 0% elastic setting. Make sure the R-HRS P0 = 1.228 GeV.
• Move the target to "15 cm Dummy"
• Take R-HRS run with same setting as previous step.
• Take data with this setting for 1 hour

Ebeam (GeV)	k' (GeV)	RQ1	Raster	θe (deg)	ΔP (%)	Rate [Hz] at 40 μA	hours at 40 μA	Good Electrons
2.217	1.228	246.10	2 x 2 mm2	48.75	0	19.5	1	70k events

Step R4: Procedure without Sieve-slit

• Time estimate: 1 hour

* Take a run at the following kinematics without the sieve-slit collimator.
* If you need to increase the spectrometer momentum setting, make sure you cycle Q2 and Q3 as per the cycling procedure.
* Electron rates assume 9 carbon foils or 1 single carbon foil, 5 mSr acceptance, and 8% delta acceptance.
* A GMp expert will check the data quality.

Target	Ebeam [GeV]	P0 [GeV/c]	Right Q1 Current [A]	θe [deg]	Q2 [GeV2]	W [GeV]	Rate [Hz] at 60 μA	minutes at 60 μA	Good Electrons
Optics	2.217	1.0	200.41	48.75	1.51	1.287	250	15	220k events
Single Carbon	2.217	1.0	200.41	48.75	1.51	1.287	56	15	50k events

Step R5: Procedure without Sieve-slit

Target	Raster	Ebeam [GeV]	P0 [GeV/c]	Right Q1 Current [A]	θe [deg]	Minutes
15cm LH2	2 x 2 mm2	2.217	1.204	241.29	48.75	Run parallel with LHRS optics step L4