Procedure without Sieve-slit
* 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.
* Rates assume 5 carbon 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.
Ebeam [GeV] |
P0 [GeV/c] |
θe [deg] |
Q2 [GeV2] |
W [GeV] |
Rate [Hz] at 20 μA |
minutes for 235k events at 20 μA |
1.9 |
0.75 |
43.7 |
0.79 |
1.500 |
197 |
20 |
Procedure with Sieve-slit
* 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.
* Repeat the above with the beam position shifted so that you see a vertical shift by one row.
* Rates assume 5 carbon foils, only 25 out of 63 sieve holes have events (~ 0.265 mSr acceptance), and 9% delta acceptance.
* Note: if the right HRS minimum angle is 35 degrees instead of 33 degrees, then the rate will be ~ 50 Hz instead.
Ebeam [GeV] |
P0 [GeV/c] |
θe [deg] |
Q2 [GeV2] |
W [GeV] |
Rate [Hz] at 20 μA |
minutes for 100k events at 20 μA |
2.0 |
0.95 |
33.0 |
0.61 |
1.496 |
66 |
25 |
Delta Scan with Hydrogen Elastic
* Trained personnel will be required to remove the 1-inch lead sieve-slit collimator onto 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.
Ebeam (GeV) |
k' (GeV) |
θe (deg) |
ΔP (%) |
Rate [Hz] at 20 μA |
minutes for 10k events at 20 μA |
2.0 |
1.5478 |
33.0 |
-4 |
12 |
14 |
2.0 |
1.518 |
33.0 |
-2 |
12 |
14 |
2.0 |
1.4882 |
33.0 |
0 |
12 |
14 |
2.0 |
1.4585 |
33.0 |
+2 |
12 |
14 |
2.0 |
1.4287 |
33.0 |
+4 |
12 |
14 |
Elastic from Hydrogen
* If you need to increase the spectrometer momentum setting, make sure you cycle Q2 and Q3 as per the cycling procedure.
* Elastic electron-proton measurement. Assuming a 15 cm LH2 target, a spectrometer acceptance of 5 msr and elastic from Eric's rate program
to compute the cross-section.
Ebeam (GeV) |
k' (GeV) |
θe (deg) |
Q2 (GeV2) |
Rate [Hz] at 20 μA |
minutes for 40k events at 20 μA |
2.0 |
1.488 |
33.0 |
0.96 |
12 |
55 |