Difference between revisions of "Spectrometer Optics First pass 48p75d"

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(Integration with LHRS plan)
(Integration with LHRS plan)
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<td> LHRS: elastic LH2, 60 uA<br>
 
<td> LHRS: elastic LH2, 60 uA<br>
 
RHRS: DIS  on single carbon and optics, 60 uA</td>
 
RHRS: DIS  on single carbon and optics, 60 uA</td>
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<td><b>R4 Completed</b><br>L4 not started</td>
 
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Revision as of 16:01, 16 October 2016

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