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Physics Shift Report

Dates: 04-10-2017 - 08-10-2017
Shifter: Christoper Hunt
Run Numbers: 09845 - 09904

Analysis Objectives

Run Number Table

Objective Analysis Code Channel Setting Run Numbers
lH2 Scattering S14a Field Off 3-170+M3-Test1 9854, 9856, 9859, 9861, 9882
S14b Field Off 3-200+M3-Test2 9855, 9857, 9858, 9860, 9881
S14c Field Off 3-140+M3-Test3 9862, 9863, 9864, 9865, 9875, 9876, 9877, 9878, 9879, 9880
lH2 Emittance Evolution H30a 2017-02-5 3-140+M3-Test3 9867
H30b 2017-02-5 4-140+M3-Test2 9868, 9871, 9873, 9874
H30c 2017-02-5 10-140+M3-Test4 9869, 9870
H31a 2017-02-6 3-140+M3-Test3 9883, 9888, 9893, 9897, 9903
H31b 2017-02-6 4-140+M3-Test2 9884, 9885, 9889, 9894, 9898, 9904
H31c 2017-02-6 10-140+M3-Test4 9886, 9887, 9890, 9891, 9892, 9895, 9896, 9899, 9900, 9901, 9902
Momentum Scan/Alignment H29a 2017-02-4 3-170+M3-Test1 9845, 9850
H29b 2017-02-4 3-200+M3-Test2 9846, 9848, 9849, 9851
H29c 2017-02-4 3-120+M3-Test1 9847, 9852

Notes

Runs containing a field flip in SSDM2:
09867 - 09874

Elog, CDB, and Reconstruction

Elog entries: All ok.

CDB uploaded: All ok.

Online reconstruction: All ok.

Notes

M2D Flip

Friday 6th Oct.
Suspicious readings from the FC force metres, and a reduced transmission led the experts to believe that SSDM2 was powered in reverse.

Day was spent trying to validate that assumption using reconstructed tracks.

The residual between projected phi-angles and reconstructed phi-angles was used to exmine the data. In theory, if a coil is flipped, the particle track spends some time rotating in the opposite direction than it otherwise would. Therefore the reconstructed phi-angle would differ from the predicted. ( phi = atan2(py, px) )

Previous data sets showed residuals centred very close to zero - indicating that the number of rotations was approximately as expected.

Data from run 09867 showed a notable deviation from zero which was removed when a geometry containing a field flip was introduced. This was more than enough proof for the magnet experts to proceed in flipping the current leads to M2.

General

  • There is a PMT power supply issue in the EMR plane 26. This is known about by the experts so no problem.
  • lH2 Geometry within the reconstruction was fixed half way through the Physics Shifter cycle. (Runs 09895-09896) Take care with track extrapolation.
  • Noticed that Pion Ref Run 09853 shows a suprisingly well focussed beam at TOF2. This is presumably a fluke of the optics+initial beam parameters?

Updated by Hunt, Christopher over 4 years ago · 11 revisions