PC-2015-07-10¶

Present:
Celeste Pidcott
Tanaz Mohayai
Dimitrije Maletic
John Nugent
Paul Soler

Celeste Pidcott:

• Analysis algorithm - Tim Carlisle's thesis; take a beam going through the absorber and propagate its upstream tracker reference plane p vector through the fields to the absorber; propagate it backwards through the downstream field; use propagated vectors
• Sources of error
  • PID
  • Tracker resolution:- beam momentum dependence?
  • Misalignment of the tracker
  • Knowledge of magnetic fields
  • Windows and Helium in the tracker
  • Knowledge of the absorber density/thickness profile of the absorber
    • lH2 temperature + window geometry
    • Lithium Hydride density profile
• Beam characteristics
  • "high statistics for an empty channel"
  • "high statistics for a full channel"

John Nugent:

• Analysis - fit straight tracks upstream and downstream; propagate them forwards and backwards, take dot product between the two vectors, consider other materials as a systematic; angle between the two vectors is a measure of the scattering
• Sources of error
  • Tracker to tracker misalignment
    • Liaise with Chris Hunt; straight tracks is crucial step
    • Paul Soler consider doing a "global fit" alignment i.e. invert the matrix
    • ACTION: Rogers to make a "catch-up" meeting with Chris Hunt
  • Remnant fields
    • ACTION: Rogers to send references to Nugent regarding the expansion of fields off-axis
  • Windows and Helium in the tracker
  • Knowledge of the absorber density/thickness profile of the absorber
    • lH2 temperature + window geometry
    • Lithium Hydride density profile
  • Momentum measurement with the TOF
    • Victoria Blackmore is resurrecting Mark Rayner's TOF track finding routine
  • Tracker angle exposed 60 mrad on the tracker vs 70 mrad RMS distribution width
• Beam characteristics
  • Trigger should be TOF2
    • Clip the high-angle scatters
  • 3 pi setting, 140, 200, 240

Tanaz Mohayai:

• Analysis - material physics measurements
  • Longitudinal emittance
  • dE/dx measurements; use the energy loss as a function of position to measure the energy loss
  • Looking at MAUS, running the simulation

Date of next meeting
Friday 17th July 15:00 BST