View source for Spectrometer Optics First pass 48p8d

==== Step R1: Procedure with Sieve-slit ====
* Time estimate: 12 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 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.
 * <b>Before moving on to the next target, a GMp expert will determine online how many good electron events have been collected. </b>
<table border="1"  style="width:80%">
  <tr>
    <td>Target</td>
    <td>E<SUB>beam</SUB> [GeV]</td>
    <td>P<sub>0</sub> [GeV/c]</td>
    <td>Raster</td>
    <td>&theta;<SUB>e</SUB> [deg]</td>
    <td>Q<SUP>2</SUP> [GeV<SUP>2</SUP>]</td>
    <td>W [GeV]</td>
    <td> Rate [Hz] at 20 &mu;A</td>
    <td> hours at 20 &mu;A</td>
    <td> Good Electrons</td>
  </tr>
  <tr>
    <td>Optics</td>
    <td>2.301</td>
    <td>0.75</td>
    <td><b>Off</b></td>
    <td>48.74</td>
    <td>1.18</td>
    <td>1.617</td>
    <td>5.6</td>
    <td>5</td> 
    <td>100k events</td>
  </tr>
  <tr>	
    <td>4 cm Dummy</td>
    <td>2.301</td>	
    <td>0.75</td>	
    <td>1x1 mm<sup>2</sup></td>
    <td>48.74</td>	
    <td>1.18</td>	
    <td>1.617</td>	
    <td>3.5</td>	
    <td>4</td>	
    <td>50k events</td>	
  </tr>	
  <tr>	
    <td>Carbon single foil</td>
    <td>2.301</td>	
    <td>0.75</td>	
    <td><b>Off</b></td>
    <td>48.74</td>	
    <td>1.18</td>	
    <td>1.617</td>	
    <td>2.2</td>	
    <td>1.3</td>	
    <td>10.3k events</td>	
  </tr>
  <tr>	
    <td>15 cm LH2</td>
    <td>2.301</td>	
    <td>0.75</td>	
    <td>2x2 mm<sup>2</sup></td>
    <td>48.74</td>	
    <td>1.18</td>	
    <td>1.617</td>	
    <td>20.0</td>	
    <td>1.3</td>	
    <td>96k events</td>	
  </tr>	
</table>
<br>

==== Step R2: Delta Scan with Proton Elastic (without sieve slit)====
* Time estimate: 3 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 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 rate from inelastic events or from the target endcaps. 
 * The Q<sup>2</sup> for these settings is 1.96 GeV<sup>2</sup>.

<table border="1"  style="width:80%">
  <tr>
    <td>E<SUB>beam</SUB> (GeV)</td>
    <td>k' (GeV)</td> 
    <td>Raster</td>
    <td>&theta;<SUB>e</SUB> (deg)</td>
    <td>&Delta;P (%)</td>
    <td>Rate [Hz] at 20 &mu;A</td>
    <td>minutes at 20 &mu;A</td>
    <td>Good Electrons</td>
  </tr>
  <tr>
    <td>2.301</td>
    <td>1.304</td>
    <td>2x2 mm<sup>2</sup></td>
    <td>48.74</td>
    <td>-4</td>
    <td>176</td>
    <td>20</td>
    <td>210k events</td>
  </tr>
  <tr>
    <td>2.301</td>
    <td>1.279</td> 
    <td>2x2 mm<sup>2</sup></td>
    <td>48.74</td>
    <td>-2</td>
    <td>176</td>
    <td>20</td>
    <td>210k events</td>
  </tr>
  <tr>
    <td>2.301</td>
    <td>1.254</td> 
    <td>2x2 mm<sup>2</sup></td>
    <td>48.74</td>
    <td>0</td>
    <td>176</td>
    <td>50</td>
    <td>500k events</td>
  </tr>
  <tr>
    <td>2.301</td>
    <td>1.229</td> 
    <td>2x2 mm<sup>2</sup></td>
    <td>48.74</td>
    <td>+2</td>
    <td>176</td>
    <td>20</td>
    <td>210k events</td>
  </tr>
  <tr>
    <td>2.301</td>
    <td>1.203</td>  
    <td>2x2 mm<sup>2</sup></td>
    <td>48.74</td>
    <td>+4</td>
    <td>176</td>
    <td>20</td>
    <td>210k events</td>
  </tr>
</table>
<br>

==== Step R3: Dummy Target Runs ====

* Go back to the &Delta;P = 0% elastic setting. Make sure the R-HRS P0 = 1.254 GeV.
* Move the target to "15 cm Dummy"
* Take R-HRS run with same setting as previous step. We need at least 100 k events.
* Take data with this setting for 1 hour
<br>
<table border="1"  style="width:80%">
 <tr>
    <td>E<SUB>beam</SUB> (GeV)</td>
    <td>k' (GeV)</td> 
     <td>Raster</td> 
    <td>&theta;<SUB>e</SUB> (deg)</td>
    <td>&Delta;P (%)</td>
    <td>Rate [Hz] at 20 &mu;A</td>
    <td>hours at 20 &mu;A</td>
    <td>Good Electrons</td>
  </tr>
 <tr>
    <td>2.301</td>
    <td>1.254</td> 
    <td>2x2 mm<sup>2</sup></td>
    <td>48.74</td>
    <td>0</td>
    <td>13.2</td>
    <td>1</td>
    <td>50k events</td>
  </tr>
</table>

<br>

==== 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 5 carbon foils or 2 Al dummy foils, 5 mSr acceptance, and 8% delta acceptance.
 * <b>A GMp expert will check the data quality.</b>
 <br>

<table border="1"  style="width:80%">
  <tr>	
    <td>Target</td>
    <td>E<SUB>beam</SUB> [GeV]</td>	
    <td>P<sub>0</sub> [GeV/c]</td>	
    <td>Right Q1 Current [A]</td>
    <td>&theta;<SUB>e</SUB> [deg]</td>	
    <td>Q<SUP>2</SUP> [GeV<SUP>2</SUP>]</td>	
    <td>W [GeV]</td>	
    <td> Rate [Hz] at 20 &mu;A</td>
    <td> minutes at 20 &mu;A</td>
    <td>Good Electrons</td>
  </tr>	
  <tr>	
    <td>Optics</td>
    <td>2.301</td>	
    <td>0.75</td>	
    <td>153.36</td>
    <td>48.74</td>	
    <td>1.18</td>	
    <td>1.617</td>	
    <td>70.5</td>	
    <td>12</td>	
    <td>50k events</td>	
  </tr>	
  <tr>	
    <td>4 cm Dummy</td>
    <td>2.301</td>	
    <td>0.75</td>	
    <td>153.36</td>
    <td>48.74</td>	
    <td>1.18</td>	
    <td>1.617</td>	
    <td>37.4</td>	
    <td>22</td>
    <td>50k events</td>	
  </tr>	
</table>
<br>

==== Step R5: Cross-wire Target Run ====
* Time estimate: 5 hours (includes access to install wire target and left HRS Sieve-slit)

 * After the above runs are completed, ask for the target group (call Dave Meekins) to insert the cross-wire target (we are not allowed to do it).
 * '''Target expert will need to go to the Hall and manually move the target in position, so ask for controlled access before starting this step'''  
 * At the same time have the Techs or A. Camsonne install the left HRS sieve-slit.  <b>The right HRS sieve-slit remains off</b>.
 * Take a run with the cross-wire target with 2x2 mm<sup>2</sup> rastered beam, and verify that the beam is centered on the cross-wire target using spot++.
 * If the beam in not centered, then ask MCC to move the beam until the rastered beam spot is centered on the wires.
 * Once beam is centered on the cross-wire target, have MCC turn off the raster.  Make sure the spectrometers still have rates above cosmics by checking <br>the scaler rates.
 * Take a run with the with <b>raster off</b>.
 * Electron rates assume 200 &mu;m of tungsten, the rate is only for the central hole of the sieve slit (~ 0.023 mSr acceptance), and 8% delta acceptance.
 * <b>A GMp expert will determine when enough good electron events have been collected.</b>

<table border="1"  style="width:80%">
  <tr>
    <td>Spectrometer</td>
    <td>Target</td>
    <td>Raster</td>
    <td>E<SUB>beam</SUB> [GeV]</td>
    <td>P<sub>0</sub> [GeV/c]</td>
    <td>&theta;<SUB>e</SUB> [deg]</td>
    <td>Q<SUP>2</SUP> [GeV<SUP>2</SUP>]</td>
    <td>W [GeV]</td>
    <td>Rate [Hz] at 1 &mu;A</td>
    <td>minutes at 1 &mu;A</td>
    <td> Good Electrons</td>
  </tr>
  <tr>
    <td>Left HRS</td>
    <td>200 &mu;m tungsten wire</td>
    <td><b>Off</b></td>
    <td>2.301</td>
    <td>0.75</td>
    <td>48.74</td>
    <td>1.18</td>
    <td>1.617</td>
    <td>3.28</td>
    <td>30</td>
    <td>5.9k events</td>
  </tr>
  <tr>
    <td>Left HRS</td>
    <td>200 &mu;m tungsten wire</td>
    <td><b>Off</b></td>
    <td>2.301</td>
    <td>0.75</td>
    <td>48.74</td>
    <td>1.18</td>
    <td>1.617</td>
    <td>3.28</td>
    <td>30</td>
    <td>5.9k events</td>
  </tr>
</table>
<br>
* After finishing this step ask for Controlled access and call the target expert to move the wire-target out of the way. Also call Hall-A Tech on-call to remove the R-HRS sieve-slit.
<br>