Feb 25, 2018
Discuss quad scan plan from Bill and Eric
Target magnet alignment test from Simona
Meeting URL https://bluejeans.com/388466836
Meeting ID 388 466 836
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- Software update:
Merged Eric’s geometry update (#7) and mapped solenoid (#8) branches into the master
- Pending update:
Solenoid misalignment (idealFieldsWithMappedSolenoid_2). Currently using hard coded misalignment values. Set the initial values to zero for now. Will let messenger take care of the input values in the future.
Geometry updates: Dipole entrance screws
- Target magnet deflection test (Simona):
First test was done with a lock running on the downstream BPMs. Second test: Clearly shown downstream position changes as the target magnet current increases. Found out later that Raster A was ON. Downstream x positions suffer from jitter much more compared to y pos. Will have follow-up with Bob. X position shows much asymmetric variation. Need to understand data (Simona will discuss with Yves). Eric’s simulation studies with 1 mm shift (in x and y) and 1 mrad angle offset show that the effect on A_zz is minimal. Will have detailed look with the cemetery plot.
- Simulation updates:
Bill: https://mollerpol.jlab.org/DocDB/0000/000020/001/feb25th2019.pdf Revisited quad scans with the geometry update from the survey. Run plan tables for the quad scans were shown (three quads, one quad solutions) Started looking at the BCM calibration data. BCM frequency needs to be checked w.r.t Faraday Cup measurements or Unser current. However, the unser signal will be too noisy for the low current.
Eric: https://hallaweb.jlab.org/dvcslog/moller/88 Solenoid misalignment simulation: simulation with misaligned field. Tested with conservative misalignment for 1 mm offset (in x and y) as well as 1 mrad angle offset. Effect on A_zz is < ~0.2%. Will have detailed look with the cemetery plot. Updated geometry from the survey. Expect to have a few additional fixes on the detector geometry from further discussion with Bill. Quad scan tables will be sent out.
Low current Moller DAQ data: https://logbooks.jlab.org/entry/3659384.
Previous scan (30-25-20uA steps): https://logbooks.jlab.org/entry/3656464