Difference between revisions of "Fall 2016 LHRS optic plans"

From Hall A Wiki
Jump to: navigation, search
(→‎Step L1: Procedure with Sieve-slit)
(→‎Step L4: Proton Elastic Kinematics)
 
(36 intermediate revisions by 3 users not shown)
Line 1: Line 1:
 
==== Step L1: Procedure with Sieve-slit ====
 
==== Step L1: Procedure with Sieve-slit ====
−
* Time estimate: 6 hours
+
* Time estimate: 1 hour
  
 
  * Trained personnel will be required to install the 1-inch tungsten sieve-slit collimator onto the front face of the HRS.
 
  * Trained personnel will be required to install the 1-inch tungsten sieve-slit collimator onto the front face of the HRS.
Line 7: Line 7:
 
  * 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 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.
 
  * 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>Adjust the prescale factors to keep the DAQ deadtime below 10%</b>.
 
  * <b>Before moving on to the next target, a GMp expert will determine online how many good electron events have been collected. </b>
 
  * <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%">
 
<table border="1"  style="width:80%">
Line 37: Line 38:
 
     <td>2.217</td>
 
     <td>2.217</td>
 
     <td>1.0</td>
 
     <td>1.0</td>
−
     <td>3x3 mm<sup>2</sup></td>
+
     <td>2 x 2 mm<sup>2</sup></td>
 
     <td>17.5</td>
 
     <td>17.5</td>
 
     <td>0.20</td>
 
     <td>0.20</td>
Line 48: Line 49:
 
<br>
 
<br>
  
−
==== Step L2: Delta Scan with Proton Elastic (without sieve slit)====
+
==== Step L2: Delta Scan with Proton Elastic (with sieve slit)====
−
* Time estimate: 3-4 hours
+
* Time estimate: 1.5 hours
  
−
  * Trained personnel will be required to remove the 1-inch tungsten sieve-slit collimator from the front face of the HRS.
+
  * Keep the 1-inch tungsten sieve-slit collimator on the front face of the left HRS.
 
  * Take runs with the 15 cm liquid hydrogen target for the elastic kinematics in the table.
 
  * 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.
+
  * Wait until the left 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.
 
  * 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.  
+
  * 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 1.86 GeV<sup>2</sup>.
+
* <b>Adjust the prescale factors to keep the DAQ deadtime below 10%</b>.
 +
  * The Q<sup>2</sup> for these settings is 0.41 GeV<sup>2</sup>.
  
 
<table border="1"  style="width:80%">
 
<table border="1"  style="width:80%">
Line 62: Line 64:
 
     <td>E<SUB>beam</SUB> (GeV)</td>
 
     <td>E<SUB>beam</SUB> (GeV)</td>
 
     <td>k' (GeV)</td>  
 
     <td>k' (GeV)</td>  
 +
    <td>LQ1 (A)</td>
 
     <td>Raster</td>
 
     <td>Raster</td>
 
     <td>&theta;<SUB>e</SUB> (deg)</td>
 
     <td>&theta;<SUB>e</SUB> (deg)</td>
 
     <td>&Delta;P (%)</td>
 
     <td>&Delta;P (%)</td>
−
     <td>Rate [Hz] at 60 &mu;A</td>
+
     <td>Rate [Hz] at 10 &mu;A</td>
−
     <td>minutes at 60 &mu;A</td>
+
     <td>minutes at 10 &mu;A</td>
 
     <td>Good Electrons</td>
 
     <td>Good Electrons</td>
 
   </tr>
 
   </tr>
 
   <tr>
 
   <tr>
 
     <td>2.217</td>
 
     <td>2.217</td>
−
     <td>1.277</td>
+
     <td>2.078</td>
−
     <td>3x3 mm<sup>2</sup></td>
+
     <td>433.45</td>
 +
    <td>2 x 2 mm<sup>2</sup></td>
 
     <td>17.5</td>
 
     <td>17.5</td>
 
     <td>-4</td>
 
     <td>-4</td>
−
     <td>650</td>
+
     <td>10,000 (2500 Hz with ps = 4) </td>
 
     <td>10</td>
 
     <td>10</td>
−
     <td>390k events</td>
+
     <td>1M events</td>
 
   </tr>
 
   </tr>
 
   <tr>
 
   <tr>
 
     <td>2.217</td>
 
     <td>2.217</td>
−
     <td>1.253</td>  
+
     <td>2.038</td>  
−
     <td>3x3 mm<sup>2</sup></td>
+
     <td>425.11</td>
 +
    <td>2 x 2 mm<sup>2</sup></td>
 
     <td>17.5</td>
 
     <td>17.5</td>
 
     <td>-2</td>
 
     <td>-2</td>
−
     <td>650</td>
+
     <td>10,000 (2500 Hz with ps = 4)</td>
 
     <td>10</td>
 
     <td>10</td>
−
     <td>390k events</td>
+
     <td>1M events</td>
 
   </tr>
 
   </tr>
 
   <tr>
 
   <tr>
 
     <td>2.217</td>
 
     <td>2.217</td>
−
     <td>1.228</td>  
+
     <td>1.998</td>  
−
     <td>3x3 mm<sup>2</sup></td>
+
     <td>416.76</td>
 +
    <td>2 x 2 mm<sup>2</sup></td>
 
     <td>17.5</td>
 
     <td>17.5</td>
 
     <td>0</td>
 
     <td>0</td>
−
     <td>650</td>
+
     <td>10,000 (2500 Hz with ps = 4)</td>
−
     <td>20</td>
+
     <td>10</td>
−
     <td>780k events</td>
+
     <td>1M events</td>
 
   </tr>
 
   </tr>
 
   <tr>
 
   <tr>
 
     <td>2.217</td>
 
     <td>2.217</td>
−
     <td>1.204</td>  
+
     <td>1.958</td>  
−
     <td>3x3 mm<sup>2</sup></td>
+
     <td>408.42</td>
 +
    <td>2 x 2 mm<sup>2</sup></td>
 
     <td>17.5</td>
 
     <td>17.5</td>
 
     <td>+2</td>
 
     <td>+2</td>
−
     <td>650</td>
+
     <td>10,000 (2500 Hz with ps = 4)</td>
 
     <td>10</td>
 
     <td>10</td>
−
     <td>390k events</td>
+
     <td>1M events</td>
 
   </tr>
 
   </tr>
 
   <tr>
 
   <tr>
 
     <td>2.217</td>
 
     <td>2.217</td>
−
     <td>1.179</td>   
+
     <td>1.918</td>   
−
     <td>3x3 mm<sup>2</sup></td>
+
     <td>400.08</td>
 +
    <td>2 x 2 mm<sup>2</sup></td>
 
     <td>17.5</td>
 
     <td>17.5</td>
 
     <td>+4</td>
 
     <td>+4</td>
−
     <td>650</td>
+
     <td>10,000 (2500 Hz with ps = 4)</td>
 
     <td>10</td>
 
     <td>10</td>
−
     <td>390k events</td>
+
     <td>1M events</td>
 
   </tr>
 
   </tr>
 
</table>
 
</table>
Line 124: Line 132:
 
==== Step L3: Dummy Target Runs ====
 
==== Step L3: Dummy Target Runs ====
  
−
* Go back to the &Delta;P = 0% elastic setting. Make sure the L-HRS P0 = 1.228 GeV.
+
* Go back to the &Delta;P = 0% elastic setting. Make sure the L-HRS P0 = 1.998 GeV.
 
* Move the target to "15 cm Dummy"
 
* Move the target to "15 cm Dummy"
−
* Take R-HRS run with same setting as previous step.
+
* Take L-HRS run with same setting as previous step.
−
* Take data with this setting for 1 hour
+
* Take data with this setting for 10 minutes
 
<br>
 
<br>
 
<table border="1"  style="width:80%">
 
<table border="1"  style="width:80%">
Line 133: Line 141:
 
     <td>E<SUB>beam</SUB> (GeV)</td>
 
     <td>E<SUB>beam</SUB> (GeV)</td>
 
     <td>k' (GeV)</td>  
 
     <td>k' (GeV)</td>  
 +
    <td>LQ1 (A)</td>
 
     <td>Raster</td>  
 
     <td>Raster</td>  
 
     <td>&theta;<SUB>e</SUB> (deg)</td>
 
     <td>&theta;<SUB>e</SUB> (deg)</td>
 
     <td>&Delta;P (%)</td>
 
     <td>&Delta;P (%)</td>
−
     <td>Rate [Hz] at 40 &mu;A</td>
+
     <td>Rate [Hz] at 10 &mu;A</td>
−
     <td>hours at 40 &mu;A</td>
+
     <td>minutes at 10 &mu;A</td>
 
     <td>Good Electrons</td>
 
     <td>Good Electrons</td>
 
   </tr>
 
   </tr>
 
  <tr>
 
  <tr>
 
     <td>2.217</td>
 
     <td>2.217</td>
−
     <td>1.228</td>  
+
     <td>1.998</td>  
−
     <td>3x3 mm<sup>2</sup></td>
+
     <td>416.76</td>
 +
    <td>2 x 2 mm<sup>2</sup></td>
 
     <td>17.5</td>
 
     <td>17.5</td>
 
     <td>0</td>
 
     <td>0</td>
−
     <td>19.5</td>
+
     <td>460</td>
−
     <td>1</td>
+
     <td>10</td>
−
     <td>70k events</td>
+
     <td>270k events</td>
 
   </tr>
 
   </tr>
 
</table>
 
</table>
Line 154: Line 164:
 
<br>
 
<br>
  
−
==== Step L4: Procedure without Sieve-slit ====
+
==== Step L4: Proton Elastic Kinematics ====
 
* Time estimate: 1 hour
 
* Time estimate: 1 hour
  
−
  * Take a run at the following kinematics without the sieve-slit collimator.
+
  * <b>Trained personnel will be required to remove the 1-inch tungsten sieve-slit collimator from the front face of the HRS</b>.
 +
* <b>Hall A Technical staff will need to move the left HRS from 17.5 degrees to 42 degrees</b>.
 
  * If you need to increase the spectrometer momentum setting, make sure you cycle Q2 and Q3 as per the cycling procedure.
 
  * 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.
+
  * Elastic electron rates assume 15 &mu;A on 15 cm LH2 target, 5 mSr acceptance.
 +
* Use the following prescale factors: ps1=1, ps2=1, ps3=1, ps8=100. All other triggers should have zero prescale factor.
 +
* The 15 cm dummy and carbon pointing runs need to be taken at the elastic setting.  So keep the momentum as is.  
 
  * <b>A GMp expert will check the data quality.</b>
 
  * <b>A GMp expert will check the data quality.</b>
−
<br>
 
  
 
<table border="1"  style="width:80%">
 
<table border="1"  style="width:80%">
 
   <tr>
 
   <tr>
 
     <td>Target</td>
 
     <td>Target</td>
 +
    <td>Raster</td>
 
     <td>E<SUB>beam</SUB> [GeV]</td>
 
     <td>E<SUB>beam</SUB> [GeV]</td>
 
     <td>P<sub>0</sub> [GeV/c]</td>
 
     <td>P<sub>0</sub> [GeV/c]</td>
−
    <td>Right Q1 Current [A]</td>
+
     <td>&theta;<SUB>e</SUB> [deg]</td>
−
     <td>&theta;<SUB>e</SUB> [deg]</td>
+
    <td>Q1 current [A]</td>
 
     <td>Q<SUP>2</SUP> [GeV<SUP>2</SUP>]</td>
 
     <td>Q<SUP>2</SUP> [GeV<SUP>2</SUP>]</td>
−
     <td>W [GeV]</td>
+
     <td> Electron Rate [Hz] at 60 &mu;A</td>
−
    <td> Rate [Hz] at 60 &mu;A</td>
+
     <td><b>Minutes</b> at 60 &mu;A</td>
−
     <td> minutes at 60 &mu;A</td>
+
−
    <td>Good Electrons</td>
+
 
   </tr>
 
   </tr>
 
   <tr>
 
   <tr>
−
     <td>Optics</td>
+
     <td>15 cm LH2</td>
 +
    <td>2 x 2 mm<sup>2</sup></td>
 
     <td>2.217</td>
 
     <td>2.217</td>
−
     <td>1.0</td>
+
     <td>1.366</td>
−
     <td>173.808</td>
+
     <td>42.0</td>
−
     <td>17.5</td>
+
     <td>284.93</td>
−
     <td>1.51</td>
+
     <td>1.57</td>
−
     <td>1.287</td>
+
    <td>1700</td>
−
     <td>250</td>
+
    <td>10 (for 1M events)</td>
−
     <td>15</td>
+
  </tr>
−
     <td>220k events</td>
+
<tr>
 +
    <td>15 cm Dummy</td>
 +
  <td>2 x 2 mm<sup>2</sup></td>
 +
    <td>2.217</td>
 +
     <td>1.366</td>
 +
     <td>42.0</td>
 +
     <td>284.93</td>
 +
    <td>1.57</td>
 +
    <td>55 at 40 &mu;A</td>
 +
     <td>35 (115k events) </td>
 
   </tr>
 
   </tr>
 
   <tr>
 
   <tr>
 
     <td>Single Carbon</td>
 
     <td>Single Carbon</td>
 +
    <td>Off</td>
 
     <td>2.217</td>
 
     <td>2.217</td>
−
     <td>1.0</td>
+
     <td>1.366</td>
−
     <td>173.808</td>
+
    <td>42.0</td>
−
     <td>17.5</td>
+
     <td>284.93</td>
−
     <td>1.51</td>
+
     <td>1.57</td>
−
     <td>1.287</td>
+
     <td>200</td>
−
     <td>56</td>
+
    <td>10 (for 120k events)</td>
−
     <td>15</td>
+
  </tr>
−
     <td>50k events</td>
+
</table>
 +
<br>
 +
 
 +
== Step L5: LHRS 12C overlap white spectra with optics target ==
 +
 
 +
* To be run during with R-HRS optics runs
 +
* Make sure Raster is OFF
 +
* Set prescale so that LT > 70%
 +
* No need to cycle magnets when lowering momentum
 +
 
 +
<table border="1"  style="width:80%">
 +
  <tr>
 +
    <td>Target</td>
 +
    <td>Raster</td>
 +
    <td>E<SUB>beam</SUB> [GeV]</td>
 +
    <td>P<sub>0</sub> [GeV/c]</td>
 +
    <td>Q1 current [Amps]</td>
 +
    <td>&theta;<SUB>e</SUB> [deg]</td>
 +
    <td><b>Minutes</b> at 50 &mu;A</td>
 +
  </tr>
 +
  <tr>
 +
    <td>Optics foils</td>
 +
    <td> OFF </td>
 +
    <td>2.217</td>
 +
     <td>1.080</td>
 +
     <td>225.277</td>
 +
     <td>42.0</td>
 +
     <td>20 (or > 1M events)</td>
 +
    </tr>
 +
<tr>
 +
    <td>Optics foils</td>
 +
    <td> OFF</td>
 +
    <td>2.217</td>
 +
    <td>1.015 </td>
 +
    <td>211.719</td>
 +
    <td>42.0</td>
 +
    <td>20 (or > 1M events)</td>
 +
  </tr>
 +
<tr>
 +
    <td>Optics foils</td>
 +
    <td> OFF</td>
 +
    <td>2.217</td>
 +
    <td> 0.954</td>
 +
    <td>198.995 </td>
 +
    <td>42.0</td>
 +
    <td>20 (or > 1M events)</td>
 +
  </tr>
 +
<tr>
 +
    <td>Optics foils</td>
 +
    <td> OFF</td>
 +
    <td>2.217</td>
 +
    <td> 0.897 </td>
 +
    <td> 187.105 </td>
 +
    <td>42.0</td>
 +
    <td>20 (or > 1M events)</td>
 +
  </tr>
 +
<tr>
 +
    <td>Optics foils</td>
 +
    <td> OFF </td>
 +
    <td>2.217</td>
 +
    <td> 0.843</td>
 +
    <td>  175.841</td>
 +
    <td>42.0</td>
 +
    <td>20 (or > 1M events)</td>
 +
  </tr>
 +
<tr>
 +
    <td>Optics foils</td>
 +
    <td> OFF </td>
 +
    <td>2.217</td>
 +
    <td> 0.792</td>
 +
    <td> 165.203</td>
 +
    <td>42.0</td>
 +
    <td>20 (or > 1M events)</td>
 +
  </tr>
 +
<tr>
 +
    <td>Optics foils</td>
 +
    <td> OFF </td>
 +
    <td>2.217</td>
 +
    <td> 0.745 </td>
 +
    <td> 155.400</td>
 +
    <td>42.0</td>
 +
    <td>20 (or > 1M events)</td>
 +
  </tr>
 +
<tr>
 +
    <td>Optics foils</td>
 +
    <td> OFF </td>
 +
    <td>2.217</td>
 +
    <td> 0.700</td>
 +
    <td>146.013 </td>
 +
    <td>42.0</td>
 +
    <td>20 (or > 1M events)</td>
 
   </tr>
 
   </tr>
 
</table>
 
</table>
 
<br>
 
<br>

Latest revision as of 15:34, 17 October 2016

Step L1: Procedure with Sieve-slit

  • Time estimate: 1 hour
* 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.
* Adjust the prescale factors to keep the DAQ deadtime below 10%.
* 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] Raster θe [deg] Q2 [GeV2] W [GeV] Rate [Hz] at 60 μA minutes at 60 μA Good Electrons
Optics 2.217 1.0 Off 17.5 0.20 1.72 540 32 1M events
15 cm LH2 2.217 1.0 2 x 2 mm2 17.5 0.20 1.72 4600 10.0 2.7M events


Step L2: Delta Scan with Proton Elastic (with sieve slit)

  • Time estimate: 1.5 hours
* Keep the 1-inch tungsten sieve-slit collimator on the front face of the left HRS.
* Take runs with the 15 cm liquid hydrogen target for the elastic kinematics in the table.
* Wait until the left 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.
* Adjust the prescale factors to keep the DAQ deadtime below 10%.
* The Q2 for these settings is 0.41 GeV2.
Ebeam (GeV) k' (GeV) LQ1 (A) Raster θe (deg) ΔP (%) Rate [Hz] at 10 μA minutes at 10 μA Good Electrons
2.217 2.078 433.45 2 x 2 mm2 17.5 -4 10,000 (2500 Hz with ps = 4) 10 1M events
2.217 2.038 425.11 2 x 2 mm2 17.5 -2 10,000 (2500 Hz with ps = 4) 10 1M events
2.217 1.998 416.76 2 x 2 mm2 17.5 0 10,000 (2500 Hz with ps = 4) 10 1M events
2.217 1.958 408.42 2 x 2 mm2 17.5 +2 10,000 (2500 Hz with ps = 4) 10 1M events
2.217 1.918 400.08 2 x 2 mm2 17.5 +4 10,000 (2500 Hz with ps = 4) 10 1M events


Step L3: Dummy Target Runs

  • Go back to the ΔP = 0% elastic setting. Make sure the L-HRS P0 = 1.998 GeV.
  • Move the target to "15 cm Dummy"
  • Take L-HRS run with same setting as previous step.
  • Take data with this setting for 10 minutes


Ebeam (GeV) k' (GeV) LQ1 (A) Raster θe (deg) ΔP (%) Rate [Hz] at 10 μA minutes at 10 μA Good Electrons
2.217 1.998 416.76 2 x 2 mm2 17.5 0 460 10 270k events


Step L4: Proton Elastic Kinematics

  • Time estimate: 1 hour
* Trained personnel will be required to remove the 1-inch tungsten sieve-slit collimator from the front face of the HRS.
* Hall A Technical staff will need to move the left HRS from 17.5 degrees to 42 degrees.
* If you need to increase the spectrometer momentum setting, make sure you cycle Q2 and Q3 as per the cycling procedure.
* Elastic electron rates assume 15 μA on 15 cm LH2 target, 5 mSr acceptance.
* Use the following prescale factors: ps1=1, ps2=1, ps3=1, ps8=100. All other triggers should have zero prescale factor.
* The 15 cm dummy and carbon pointing runs need to be taken at the elastic setting.  So keep the momentum as is. 
* A GMp expert will check the data quality.
Target Raster Ebeam [GeV] P0 [GeV/c] θe [deg] Q1 current [A] Q2 [GeV2] Electron Rate [Hz] at 60 μA Minutes at 60 μA
15 cm LH2 2 x 2 mm2 2.217 1.366 42.0 284.93 1.57 1700 10 (for 1M events)
15 cm Dummy 2 x 2 mm2 2.217 1.366 42.0 284.93 1.57 55 at 40 μA 35 (115k events)
Single Carbon Off 2.217 1.366 42.0 284.93 1.57 200 10 (for 120k events)


Step L5: LHRS 12C overlap white spectra with optics target

  • To be run during with R-HRS optics runs
  • Make sure Raster is OFF
  • Set prescale so that LT > 70%
  • No need to cycle magnets when lowering momentum
Target Raster Ebeam [GeV] P0 [GeV/c] Q1 current [Amps] θe [deg] Minutes at 50 μA
Optics foils OFF 2.217 1.080 225.277 42.0 20 (or > 1M events)
Optics foils OFF 2.217 1.015 211.719 42.0 20 (or > 1M events)
Optics foils OFF 2.217 0.954 198.995 42.0 20 (or > 1M events)
Optics foils OFF 2.217 0.897 187.105 42.0 20 (or > 1M events)
Optics foils OFF 2.217 0.843 175.841 42.0 20 (or > 1M events)
Optics foils OFF 2.217 0.792 165.203 42.0 20 (or > 1M events)
Optics foils OFF 2.217 0.745 155.400 42.0 20 (or > 1M events)
Optics foils OFF 2.217 0.700 146.013 42.0 20 (or > 1M events)


Retrieved from "https://hallaweb.jlab.org/wiki/index.php?title=Fall_2016_LHRS_optic_plans&oldid=30871"