Difference between revisions of "HRS Checkout (Experts)"
From Hall A Wiki
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</table> | </table> | ||
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| − | <li> With the above kinematics, take a run (at least 25K | + | <li> With the above kinematics, take a run (at least 25K electrons or 80 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. | ||
Revision as of 15:10, 31 January 2016
The detector checkout is best done using a fairly uniform illumination, which is provided for by 20 μA on the 15 cm LH2 target at the following kinematics:
E' = 1.0 GeV, θ = 48.8 degrees (W = 3.49 GeV, Q2 = 7.5 GeV2). The HRS electron rates should be about 5.2 Hz.
| Ebeam [GeV] | P0 [GeV/c] | θe [deg] | Collimator | Target | Fast Raster X x Y |
Beam Current | Trigger |
| 11.02 | 1.0 | 48.8 | None | 15 cm LH2 | 2 x 2 mm2 | 20 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.
