FF 20130409¶

Present:

• Chris Rogers
• Henry Nebrensky
• John Palin

During visit to MICE hall:

• Discussion on survey data
  • Survey produces xit format which appears to be proprietary binary format - requires Spatial Analyzer tool developed by New River Kinematics www.kinematics.com; DL survey crew have a licence, Jason Tarrant may also have a licence.
    • What if they go out of business?
  • Each new survey results in a new xit file
    • No clear dissemination/back up policy on these files
    • Outline agreement that copies of these should be stored on MOM laptop which is backed up
    • either emailed to MOM after each survey, or MOM can put them on a USB stick before surveyor leaves RAL
  • Did not discuss how survey should be documented; but documentation is probably required
  • Established that the survey coordinates are either left-handed or right-handed (and a conversion is not trivial) - but not which one. Presumably this comes through from the CAD model anyway.

• Discussion on survey details
  • Centre line D2-MICE-beamline
    • X axis (D2-MICE-beamline) defined by least squares fit to quadrupole mirror-plate apertures for Q4-9
    • define line-on-floor by looking at reference points on floor - brass plate under D2; floor target(sticker) in front of Q4; floor target(sticker) below the Ckovs
    • Z axis is defined by fitting to plane that includes line-on-floor and D2-MICE-beamline; and taking a line in that plane that is perpendicular to D2-MICE-beamline
  • Some discussion - how do we get a handle on where D1-D2 line is pointing wrt D2-MICE-beamline?
    • Proposed measuring around solenoid exit aperture and taking the mean to get a handle on solenoid downstream end placement
      • This requires removing the Proton Absorbers and possibly GVA1; hope to do this within the pneumatic proton absorber upgrade process. Hopefully PA apertures would end up aligned on beam centre
    • No clear technique for getting the upstream end placement
    • Noted that it was not clear that the D1-D2 line sits in the x-y plane as defined above; and this should not be assumed (if possible)
  • And finally
    • Emphasised that of all beamline components, TOF positions are most crucial to measure well.

For reference, note that the surveyor's co-ordinate system for the MICE Hall and Cooling Channel is as follows:

• X is along beamline with beam travelling in positive direction
• Y is across beamline; positive points south (towards MLCR)
• Z is vertical with up in positive direction