Difference between revisions of "HRS Checkout (Experts)"
From Hall A Wiki
| (9 intermediate revisions by one other user not shown) | |||
| Line 1: | Line 1: | ||
The detector checkout is best done using a fairly uniform illumination, which is | The detector checkout is best done using a fairly uniform illumination, which is | ||
| − | provided for by 20 μA on the | + | provided for by 20 μA on the optics target at the following kinematics: |
| − | + | The Right HRS electron rates should be about 119 Hz, and the left HRS electron rates should be about 9.8 kHz.<br> | |
| − | + | <b>Make sure to adjust the prescale factors to obtain a reasonable deadtime < 10%. </b> | |
<table border="1" style="width:80%"> | <table border="1" style="width:80%"> | ||
<tr> | <tr> | ||
| + | <td>HRS </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> | ||
| Line 16: | Line 17: | ||
</tr> | </tr> | ||
<tr> | <tr> | ||
| − | <td> | + | <td><b>Right</b></td> |
| + | <td>2.217</td> | ||
| + | <td>0.85</td> | ||
| + | <td>48.75</td> | ||
| + | <td>None</td> | ||
| + | <td>Optics</td> | ||
| + | <td>2 x 2 mm<sup>2</sup></td> | ||
| + | <td>20 μA</td> | ||
| + | <td>S0&&S2m</td> | ||
| + | </tr> | ||
| + | <tr> | ||
| + | <td><b>Left</b></td> | ||
| + | <td>2.217</td> | ||
<td>1.0</td> | <td>1.0</td> | ||
| − | <td> | + | <td>17.5</td> |
<td>None</td> | <td>None</td> | ||
| − | <td> | + | <td>Optics</td> |
<td>2 x 2 mm<sup>2</sup></td> | <td>2 x 2 mm<sup>2</sup></td> | ||
<td>20 μA</td> | <td>20 μA</td> | ||
| Line 27: | Line 40: | ||
</table> | </table> | ||
<ol> | <ol> | ||
| − | <li> With the above kinematics, take a run (at least | + | <li> With the above kinematics, take a run (at least 200K electrons or 30 minutes) and verify that all detector channels are working. |
<li> Using the same run, produce a ROOT tree, and do the following: make a spectrum of x vs. y at the focal plane. What you should see is a "spider" with 5 legs. The non-straightness of the central legs indicates there is an offset in the Z or Y direction. If you don't see a "spider" or something resembling it, then of of the polarities of the HRS magnets is set wrong (or a magnet is off). | <li> Using the same run, produce a ROOT tree, and do the following: make a spectrum of x vs. y at the focal plane. What you should see is a "spider" with 5 legs. The non-straightness of the central legs indicates there is an offset in the Z or Y direction. If you don't see a "spider" or something resembling it, then of of the polarities of the HRS magnets is set wrong (or a magnet is off). | ||
<li> Check that the signals are well timed. | <li> Check that the signals are well timed. | ||
Latest revision as of 22:02, 10 October 2016
The detector checkout is best done using a fairly uniform illumination, which is provided for by 20 μA on the optics target at the following kinematics:
The Right HRS electron rates should be about 119 Hz, and the left HRS electron rates should be about 9.8 kHz.
Make sure to adjust the prescale factors to obtain a reasonable deadtime < 10%.
| HRS | Ebeam [GeV] | P0 [GeV/c] | θe [deg] | Collimator | Target | Fast Raster X x Y |
Beam Current | Trigger |
| Right | 2.217 | 0.85 | 48.75 | None | Optics | 2 x 2 mm2 | 20 μA | S0&&S2m |
| Left | 2.217 | 1.0 | 17.5 | None | Optics | 2 x 2 mm2 | 20 μA | S0&&S2m |
- With the above kinematics, take a run (at least 200K electrons or 30 minutes) and verify that all detector channels are working.
- Using the same run, produce a ROOT tree, and do the following: make a spectrum of x vs. y at the focal plane. What you should see is a "spider" with 5 legs. The non-straightness of the central legs indicates there is an offset in the Z or Y direction. If you don't see a "spider" or something resembling it, then of of the polarities of the HRS magnets is set wrong (or a magnet is off).
- Check that the signals are well timed.
- Determine correct thresholds.
- Verify all scalers are incrementing.
- Check for double pulsing and time the wire chamber signals.
- Are the scintillator signals on scale in the ADCs?
- PID threshold checks.
