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Beam momentum measurement using TOFs: progress report. Analysis meeting, 22 January 2008 Mark Rayner – Oxford/RAL. MICE Beam Line Design, Kevin Tilley, 16-XI-07. Beam parameters at Tof-0. Kevin’s realistic TURTLE beam of muons has been propagated starting at TOF0 by the G4MICE simulation code. - PowerPoint PPT Presentation
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Analysis meeting: Beam momentum measurements using TOFsTuesday, 22 January 2008
Slide 1 of 10m.rayner1@physics.ox.ac.
uk
Beam momentum measurement using TOFs: progress report
Analysis meeting, 22 January 2008
Mark Rayner – Oxford/RAL
Analysis meeting: Beam momentum measurements using TOFsTuesday, 22 January 2008
Slide 2 of 10m.rayner1@physics.ox.ac.
uk
Beam parameters at Tof-0
MICE Beam Line Design, Kevin Tilley, 16-XI-07
Kevin’s realistic
TURTLE beam of muons has
been propagated starting at
TOF0 by the G4MICE
simulation code
Analysis meeting: Beam momentum measurements using TOFsTuesday, 22 January 2008
Slide 3 of 10m.rayner1@physics.ox.ac.
uk
Stage 2 G4MICE simulation
• 100 muons from Kevin’s realistic TURTLE beam:100 muons from Kevin’s realistic TURTLE beam:– Blue – positively charged particles, mainly Blue – positively charged particles, mainly
mu+mu+– Red – negatively charged particles, mainly Red – negatively charged particles, mainly
e-e-– Green – neutral particles, mainly photons Green – neutral particles, mainly photons
TOF0 CherenkovQ7 Q8 Q9 TOF1 Tracker 1
Analysis meeting: Beam momentum measurements using TOFsTuesday, 22 January 2008
Slide 4 of 10m.rayner1@physics.ox.ac.
uk
TOF0 & Cherenkov
Analysis meeting: Beam momentum measurements using TOFsTuesday, 22 January 2008
Slide 5 of 10m.rayner1@physics.ox.ac.
uk
Quadrupoles 7, 8 and 9
Analysis meeting: Beam momentum measurements using TOFsTuesday, 22 January 2008
Slide 6 of 10m.rayner1@physics.ox.ac.
uk
TOF1 & Tracker 1
Analysis meeting: Beam momentum measurements using TOFsTuesday, 22 January 2008
Slide 7 of 10m.rayner1@physics.ox.ac.
uk
Amplitude analysis of muons surviving to TOF1
Analysis meeting: Beam momentum measurements using TOFsTuesday, 22 January 2008
Slide 8 of 10m.rayner1@physics.ox.ac.
uk
Momentum reconstruction
• Reconstruction class TofTrack being added to G4MICE– In close collaboration with Malcolm– Very simple to begin with– Designed to be useful before trackers are operating– Details to follow at CM20– The following work is a look beyond that at the difficulties of
doing something more sophisticated
• The following numbers are Monte Carlo truth…– Designed to illustrate the intrinsic difficulties in reconstructing
momentum given TOF0 and TOF1 data• No time measurement error• No transverse position measurement error
• Neglect corner clippers– Use hit with most photoelectrons
Analysis meeting: Beam momentum measurements using TOFsTuesday, 22 January 2008
Slide 9 of 10m.rayner1@physics.ox.ac.
uk
Path between Tof-0 and Tof-10.48 m
Tof-1(same design for Tof-2)
Tof-0
0.48 m
Actual path
Straight line
between space points
Straight line
between Tof centres
muons
r0=(t0, x0, y0,z0)|MC
r| = {(x1-x0)2+(y1-y0)2}
Some definitions:
pMC
TOF1Pcrude guess
= |m
where = (r1-r0)/[(t1-t0)c]
pMC
TOF1
pCrude guess
Correctionfactor =
r1=(t1, x1, y1,z1)|MC
Analysis meeting: Beam momentum measurements using TOFsTuesday, 22 January 2008
Slide 10 of 10m.rayner1@physics.ox.ac.
uk
Prospects for momentum reconstruction
Analysis meeting: Beam momentum measurements using TOFsTuesday, 22 January 2008
Slide 11 of 10m.rayner1@physics.ox.ac.
uk
Extra Slides
Analysis meeting: Beam momentum measurements using TOFsTuesday, 22 January 2008
Slide 12 of 10m.rayner1@physics.ox.ac.
uk
Transverse phase space: horizontal
x / cmpx / MeV
-40 cm – 40 cm-100 MeV – 100 MeV
x
px
Analysis meeting: Beam momentum measurements using TOFsTuesday, 22 January 2008
Slide 13 of 10m.rayner1@physics.ox.ac.
uk
Transverse phase space: vertical
y / cmpy / MeV
-40 cm – 40 cm-100 MeV – 100 MeV
y
py
Analysis meeting: Beam momentum measurements using TOFsTuesday, 22 January 2008
Slide 14 of 10m.rayner1@physics.ox.ac.
uk
Longitudinal phase space
Analysis meeting: Beam momentum measurements using TOFsTuesday, 22 January 2008
Slide 15 of 10m.rayner1@physics.ox.ac.
uk
Momentum measurement uncertainty
• p = m0 c – assume PID ascertains m0
• Timing uncertainty– Technical challenge: progress being made in Milano
• One counter = scintillator with 2 PMTs– “…a conservative request for single counters timing resolution is 60–70
ps”» MICE Note 145
• Other factors:– 2 planes per station
» Rotated so as to yield ‘space points’– Multiple space points per muon possible/likely
• t1–t0 will be larger still
• Path length uncertainty– Software challenge: challenges remain…
• Multiple scattering in Tof-0, Cerenkov, Tof-1 and air• Focusing in quadrupoles Q7, Q8 and Q9• Limited transverse position resolution
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