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| | The Left HRS will be used during the SBS era for calibrating HCAL and possibly for a hypernuclear experiment. | | The Left HRS will be used during the SBS era for calibrating HCAL and possibly for a hypernuclear experiment. |
| − | Here's a talk about it: http://userweb.jlab.org/~rom/LHRS_BobM_17May21.pdf | + | Here's a talk about the Left HRS: http://userweb.jlab.org/~rom/LHRS_BobM_17May21.pdf |
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| | == [[Running the Left-HRS DAQ]] == | | == [[Running the Left-HRS DAQ]] == |
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| | == [[Detectors on Left HRS]] == | | == [[Detectors on Left HRS]] == |
| | == [[Analysis Software for Left HRS]] == | | == [[Analysis Software for Left HRS]] == |
| − | | + | == [[Controlling HV on Left HRS]] == |
| − | | + | |
| − | == <h4> Commissioning Plan for Left HRS </h4> == | + | |
| − | | + | |
| − | Before we use the Left HRS to commission HCAL, we need to spend some time checking the HRS itself.
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| − | Most checks of detector and the DAQ can be done with cosmics or with pulsers, but the two topics
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| − | where we need beam are: 1) Check the HV on the Cherenkov detectors (particles need to go in the right
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| − | direction, and 2) Check the magnetic optics (we can start with an optics database from the Tritium era.
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| − | | + | |
| − | Initially we'll have the HRS at about 90 degrees. We can run with beam and check detectors and look
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| − | at reconstructed angles at the target. We can do this parasitically or late at night when nobody
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| − | is in the hall. (We need the beam on target.). For the reconstructed angles, all is well if the
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| − | acceptance looks about right (a familiar rectangle) and we can compare to Monte Carlo. Later, when
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| − | we remove Bigbite, we can put in the sieve slits and check more carefully the optics. If the optics
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| − | are really bad (blurry hole pattern) we can do an optics calibration run plan. However, I doubt that
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| − | this is necessary.
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| − | | + | |
| − | <pre>
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| − | Rate calculations for e-P elastic scattering.
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| − | Assuming 15 cm LH2 target. 1 uA of beam.
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| − | | + | |
| − | Here I used some of the kinematics given in the HCAL run plan.
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| − | 4.4 GeV is not very practical.
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| − | Note, the sieve slit will cut the rate by a factor of 200.
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| − | | + | |
| − | E' is the momentum setting of the L-HRS for elastic.
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| − | | + | |
| − | E theta_HRS E' Rate
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| − | (GeV) (degrees) (GeV) (Hz for 1 uA beam)
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| − | | + | |
| − | 4.4 30.9 2.64 2.9 Hz/uA
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| − |
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| − | 4.4 34.1 2.44 1.3 Hz/uA
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| − | | + | |
| − | 4.4 61.1 1.29 0.018 Hz/uA
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| − | | + | |
| − | 4.4 64.3 1.20 0.014 Hz/uA
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| − | | + | |
| − | 4.4 67.5 1.13 0.010 Hz/uA
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| − | | + | |
| − | 4.4 70.7 1.06 0.008 Hz/uA
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| − | | + | |
| − | 2.2 30.9 1.65 216 Hz/uA ..... angle available when Bigbite removed (can run with sieve)
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| − | | + | |
| − | 2.2 34.1 1.57 100 Hz/uA
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| − | | + | |
| − | 2.2 40 1.42 29 Hz/uA
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| − | | + | |
| − | 2.2 45 1.30 11.7 Hz/uA
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| − | | + | |
| − | 2.2 80 0.75 0.27 Hz/uA .... run here at 40 uA (without sieve)
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| − | | + | |
| − | 2.2 90 0.66 0.15 Hz/uA
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| − | | + | |
| − | </pre>
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