Difference between revisions of "HRS Checkout (Experts)"
From Hall A Wiki
| 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 | + | provided for by 5 μA on the optics target at the following kinematics: |
| − | E' = | + | E' = 0.75 GeV, θ = 48.0 degrees (W = 2.38 GeV, Q<sup>2</sup> = 2.2 GeV<sup>2</sup>). The |
| − | HRS electron rates should be about 5 | + | HRS electron rates should be about 4.5 Hz. |
<table border="1" style="width:80%"> | <table border="1" style="width:80%"> | ||
<tr> | <tr> | ||
| Line 16: | Line 16: | ||
</tr> | </tr> | ||
<tr> | <tr> | ||
| − | <td> | + | <td>4.481</td> |
| − | <td> | + | <td>0.75</td> |
| − | <td>48. | + | <td>48.0</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> | + | <td>5 μA</td> |
<td>S0&&S2m</td> | <td>S0&&S2m</td> | ||
</tr> | </tr> | ||
Revision as of 13:18, 4 February 2016
The detector checkout is best done using a fairly uniform illumination, which is provided for by 5 μA on the optics target at the following kinematics:
E' = 0.75 GeV, θ = 48.0 degrees (W = 2.38 GeV, Q2 = 2.2 GeV2). The HRS electron rates should be about 4.5 Hz.
| Ebeam [GeV] | P0 [GeV/c] | θe [deg] | Collimator | Target | Fast Raster X x Y |
Beam Current | Trigger |
| 4.481 | 0.75 | 48.0 | None | Optics | 2 x 2 mm2 | 5 μA | S0&&S2m |
- With the above kinematics, take a run (at least 25K electrons or 80 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.
