Project

General

Profile

FF 2014-11-26

Meeting on Wednesday 26th November, at RAL. We will be in room R66 G.06 (the room used for the hall meeting).

Time Title Presenter File
10:00 Step IV Data Taking and Papers Chris Rogers Preparing_for_Step_IV_Data.pdf
10:20 Track Reconstruction Resolution at Step IV David Adey Adey_Tracker_AnalysisWorkshop_141126.pdf
10:40 Track Reconstruction Resolution at Step IV Melissa Uchida Tracker_Alignment_analysis_26_11_14.pdf
11:00 Particle ID at Step IV Celeste Pidcott PIDatStepIV.pdf
11:20 Measurement of Magnetic Alignment Chris Rogers Measuring_Magnet_Alignment.pdf
11:40 Discussion All
13:00 Lunch All
13:30 Hall Meeting (for those that are interested) All
14:30 Field Mapping Status Victoria Blackmore slides (pdf, NB gifs won't animate)
14:50 Quality of Transported Beam Chris Hunt beam_transport_quality.pdf
15:10 Online Analysis tools Chris Rogers online_analysis_tool.pdf
15:30 Offline Analysis tool Chris Hunt offline_analysis_tool.pdf
15:50 Batch processing and physics block challenge Ryan Bayes Simulations.pdf
16:10 Discussion All

The atmosphere is intended to be ad-hoc - so don't consider this such a rigid structure.

Phone Details

Where possible we will use the regular MICE phone bridge (which has free phone numbers).

Between 15:00 and 16:00 the MAUS crew will take over. We can divert to this number

We can use this number if there are any other interruptions/conflicts.

Briefing

  • Step IV Data Taking, Proposed Papers - Chris Rogers
    • Best plot prize?
  • Track reconstruction at Step IV David Adey, Melissa Uchida
    • What will be the resolution in x,y,px,py,pz?
    • What measurements are required to demonstrate this resolution? Do we talk about e.g. matching between upstream and downstream tracker here?
    • job list...
  • Particle ID at Step IV Celeste Pidcott
    • What will be the efficiency and purity of beam PID?
    • How do we demonstrate this efficiency/purity? Fight upstream and downstream? Select at D2 for measurement?
    • job list...
  • Measurement of Magnetic Alignment Chris Rogers
    • Field mapping status and "dead reckoning" procedure Victoria Blackmore
    • How do we measure the magnetic alignment? What magnet settings? Any issues e.g. hysteresis, long term stability, current dependent alignment? Chris Rogers, Chris Hunt
    • job list...
  • Quality of transported beam Chris Hunt
    • Beam selection procedure Chris Rogers
    • What beam parameters do we want to measure?
    • Resolutions on measured parameters?
    • job list...
  • Support
    • Online analysis tool Chris Rogers
    • Offline analysis tool Chris Hunt
    • Batch processing status Ryan Bayes
    • Beamline settings Jaroslaw Pasternak
If time:
  • Skeleton outline of "First observation of normalised emittance reduction" paper Chris Rogers

Remember aim is to get a list of measurements/plots and a "job list"; first pass on the data required to support this paper.

Notes

It was a very useful and provocative meeting. Rogers notes:

Summary of Actions

These are general actions, they are general and hence mostly on Rogers... specific actions are contained in the subheadings as "Job List" (and I think folks mostly know what they are doing).

  • ACTION (Pasternak/Rogers): determine magnetic settings routine - do we imagine "equivalent coil"? Implement iron in MAUS? Run everything through OPERA?
  • ACTION (Pasternak/Rogers): determine standard magnetic settings for commissioning e.g. magnet currents for 420 mm beta in solenoid mode
  • ACTION (Pasternak/Rogers): determine standard beamline settings
  • ACTION (Dobbs/Rogers): specify MAUS implementation of "estimate of the error on the field as a function of position" in detail and implement
  • ACTION (Someone): would like to know how well the bobbin on which the coils are wound is aligned to the SS bores
  • ACTION (Rogers): arrange a "magnet bolting down meeting" to determine how Physics group does the handover of the magnet axes and how the installation will work
  • ACTION (Rogers): Need to consider how we staff the "accelerator physics" during running
  • ACTION (Rogers): Xboa specification document
  • ACTION (Rogers): Bring in Dobbs MAUS analysis framework to xboa?
  • ACTION (Rogers/delegate): need an accelerator physics helper for the analysis of existing batch simulations

General Comments

  • We need full current settings, including effect of iron. We need some mechanism (responsible person) to generate such field maps on a case-by-case basis; presumably need access to Opera
    • ACTION (Rogers/Pasternak): determine magnetic settings routine - do we imagine "equivalent coil"? Implement iron in MAUS? Run everything through OPERA?
    • ACTION (Rogers/Pasternak): determine standard magnetic settings for commissioning e.g. magnet currents for 420 mm beta in solenoid mode
  • We need an estimate of the error on the field as a function of position. Feature request that this should be available from the field API (presumably MAUS)
    • ACTION (Dobbs/Rogers): specify this in detail and implement

Step IV Data Taking and Papers - Chris Rogers

Consider adding subsections:

  • Confirmation of input beams, discuss diffuser design and beam matching through the diffuser
  • Energy loss in windows (probably as subsection of "quality of transported beams")

Tracker - David Adey

  • Look at hit efficiency, reconstruction efficiency; this can be done more or less internally to the tracker
    • Note that detector + reconstruction efficiency needs to be added to the "track reconstruction at Step IV" as a measurement; mainly a concern downstream, but we should report upstream also.
  • Look at position residual by comparing track position with view hit
  • No algorithm to understand momentum residual
    • Suggested compare upstream and downstream trackers (relies on good understanding of the fields)
  • No beam settings or requirements proposed
    • Suggest high emittance beam to check large r fibres, use LED where stats are low
    • Low pz spread can be advantageous; select in TOF
  • Job list
    • Fix Kalman fit
    • Look at dependency on Bz, presumably using "standard" alignment tolerances 1 mm 1 mrad on the bobbin (all coils)
    • If required, add non-axial Bz to reconstruction routines (requires new calculation of propagator matrix, may be significant refit

Global - Melissa Uchida

  • Discussion on how we align trackers
  • Trackers installed by;
    • Taking a vector which is normal to the plane made by the survey pillars
    • Aligning this vector to the centre of the magnet bore opening (beam pipe)
    • Projecting the vector down the beam pipe to the tracker
    • ACTION: would like to know how well the bobbin on which the coils are wound is aligned to the bore
  • Propose job list:
    • Back of envelope calculations
    • Massive MC job - some discussion as to how "massive" this should be
    • Data analysis
    • Magnetic scan to determine magnetic axis
      • Ill-defined for me (Rogers) what this means
  • Missing:
    • Alignment of TOFs
    • Alignment to KL/EMR
    • (Alignment to Ckov)

PID - Celeste Pidcott

  • Propose varying D1 to obtain beams with different admixtures of pions, muons and clearly separated pion peaks
    • Use D2 to select the appropriate momentum band
    • Use the mixed pion/muon log likelihood and tracker vs TOF PID variable
    • Figure out e.g. how many pions are misidentified as muons
  • Propose using upstream vs downstream
    • Check PID upstream == PID downstream
    • Where particles have decayed, check that number of decays matches the particle lifetime

Field Mapping - Victoria Blackmore

  • Have a calculation of the field map in FC1 ( 0.0022 radian tilt in x, etc); some cross-checks still needed
  • Now FC2, SSU, SSD should be easy, right?
  • ACTION (Rogers): arrange a "magnet bolting down meeting" to determine how Physics group does the handover of the magnet axes and how the installation will work

Measuring Magnet Alignment

  • Use beam based alignment technique
  • To get measurable displacements, need to change magnet currents by 10% or more
  • Settings
    • Mainly go with low emittance setting and watch beam centroid move
    • High emittance setting for transfer matrix changes - but looks hard
    • Scan around "nominal setting" which corresponds to some baseline optics
    • Scan around "optimal setting" designed to give biggest kick per coil
    • Check for non-linearity in the coils
    • Hysteresis check - flip polarity?
    • Check for reproducibility; daily reference settings
  • Job list
    • Figure out analytical behaviour
    • Figure out analysis routine, compare with "laptop study"
    • Run batch MC with "standard" misalignment set
    • Consider modelling non-linearities etc

Quality of Transported Beam

  • Chris Hunt had lots of things on his slides
  • Need to descope - focus on
    1. Kalman fit
    2. Measuring beam optics functions and emittances (with errors); and transmission
  • Beam optics measurements will be with empty lH2 absorbers
  • Job list
    • Determine errorss on measured parameters
    • Look at source of errors
    • MC of "standard" setting

Online Analysis Tool - Chris Rogers

  • Specification for online analysis tool
    • In addition to slides; we DO want beam selection routines; we DO want non-axial stuff; we DO NOT want undecays
  • Wish to support Rogers and Blackmore routines
    • If one doesn't work out, we fall back to the other
    • Request Rogers routines to have the "sliders" approach - fast turnaround etc
    • Request Rogers routines to fix the geometry
  • No decision as to primary routine
  • ACTION (Rogers): Need to consider how we staff the "accelerator physics"
    • Do we want an on-call system... or something

Offline Analysis Tool - Chris Hunt

  • Agreed that we continue to use xboa
  • Agreed that it should continue to be a 3rd party library in MAUS
  • Request that the C++ part should be enhanced
  • ACTION (Rogers): Specification document; think about resource requirements, do we do an event loop or hold everything in memory, etc
  • ACTION (Rogers): Bring in Dobbs framework
  • ACTION (Rogers/Dobbs): Run analysis validation as part of the batch reco (and MC?)

Simulation - Ryan Bayes

  • Ryan outlined the simulation status
  • ACTION (Rogers/delegate): need an accelerator physics helper for the analysis of existing simulations
  • Ryan requested priorities
    1. Commissioning/alignment (as per this meeting)
    2. First observation of normalised emittance reduction using MICE
    3. Everything else (priorities TBD)

Preparing_for_Step_IV_Data.pdf (69.6 KB) Rogers, Chris, 21 November 2014 09:03

online_analysis_tool.pdf (51.7 KB) Rogers, Chris, 21 November 2014 10:07

Adey_Tracker_AnalysisWorkshop_141126.pdf (603 KB) Adey, David, 26 November 2014 00:11

Tracker_Alignment_analysis_26_11_14.pdf (313 KB) George, Melissa, 26 November 2014 01:25

PIDatStepIV.pdf (436 KB) Pidcott, Celeste, 26 November 2014 09:17

Measuring_Magnet_Alignment.pdf (362 KB) Rogers, Chris, 26 November 2014 09:55

analysis_workshop_presentation.odp - Field mapping (8.92 MB) Blackmore, Victoria, 26 November 2014 12:55

Simulations.pdf (188 KB) Bayes, Ryan, 26 November 2014 14:03

beam_transport_quality.pdf (212 KB) Hunt, Christopher, 26 November 2014 14:08

offline_analysis_tool.pdf (87.1 KB) Hunt, Christopher, 26 November 2014 14:09

mapping_presentation.pdf (488 KB) Blackmore, Victoria, 27 November 2014 10:11