15:00 in the ATLAS building

Phone Details


  • Field mapping (Victoria/John Cobb/Jo Langford)
  • Theoretical magnet parameters and effect of iron (Jaroslaw/Victoria)
  • Transfer matrix and magnet alignment (Sophie/Chris Rogers)
  • Beamline commissioning (Victoria/Jaroslaw)
    • Contingency if DS is not available in 2016
    • Beamline commissioning data in December?
  • Optics without M1 at SSD (Chris Rogers/Scott Berg)
    • Tracking (Ao/Ryan/Chris Hunt/Chris Rogers)
    • Ao's work as presented attachment:StepIV_noM1_update_Dec17.pdf
    • Ao's work with 150 mm aperture in SciFi region attachment:StepIV_noM1_update_Dec17_SciFi.pdf
    • Algorithm to calculate the phase space volume (vs RMS emittance)
    • Track fitting/extrapolation for indirect emittance measurement
  • Bayesian analysis (Rob Ryne)
  • Demonstration of Ionisation Cooling paper (Jaroslaw/JB Lagrange)
  • Demonstration of Ionisation Cooling optics w/o Match Coil 1 in downstream Spectrometer Solenoid (Dave Neuffer)
  • Demonstration of Ionisation Cooling alignment and tolerances (Alan Young)
  • Date of next meeting
    • 7th January optics review special?
    • 14/15 January optics review


Hall probes
  • Time is negative
  • Hall probe closest to end plate is "-67"
  • Rogers: compare hall probe with field during the ramp
Transfer matrix and optical alignment
  • Looking at straight tracks data and calculating transfer matrix, compare with theory
Step IV optics
  • ACTION BROSS: revised SSD limits with previous quench limit and safety factor
  • Bross: Need to add the fiducial cuts
  • Pasternak: use emittance of 140/200*6
    • Rogers: send an explanation?
  • Tracker beampipe 200 mm should be 150 mm
  • Hybrid mode: Bross - from hardware pov no problem; may require additional training
    • Risk that we may get additional training
  • Rogers raised issue on M2 operation
    • Alan Bross: does not believe that running M2 increases the risks
    • Jaroslaw Pasternak: concerns about risk to push emittance measurement to the end
    • Jaroslaw Pasternak: can we get good enough transmission? Ao has run simulations that show we can
  • John Cobb: we have not shown that we have a solution
    • There is no plot that we can stand behind at the 100 % level
    • Scott has demonstrated that we increase the phase space density
    • Rogers: we need to do the full reconstruction and analysis chain for an optimised run
    • Scott: and we should do the full analysis that shows particles didn't scatter out of the aperture to produce amplitude increase (or whatever)
    • Bross: we will need to have a crisp answer to the discussion at the review
  • Bross: further comments for Ao are welcome (by email)

Demo_Ionisation_Cooling_Alignment_ARY_171215.pdf (582 KB) Rogers, Chris, 17 December 2015 13:57

Statistical_error_on_4d_emittance.pdf - Statistical errors? (144 KB) Blackmore, Victoria, 17 December 2015 14:51

Analysing_and_interpreting_Hall_probe_data.pdf (329 KB) Pasternak, Jaroslaw, 17 December 2015 14:59