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Beam momentum measurement using TOFs: progress report. Analysis Meeting, February 2008 Mark Rayner – Oxford/RAL. Beams/scenarios to investigate. Particle composition of beam Muons/pions/protons 100% muon beams in current simulations Varying emittances and amplitude distributions - PowerPoint PPT Presentation
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Analysis Meeting – [email protected] – Slide 1
Beam momentum measurement using TOFs: progress report
Analysis Meeting, February 2008Mark Rayner – Oxford/RAL
Analysis Meeting – [email protected] – Slide 2
Beams/scenarios to investigate
• Particle composition of beam– Muons/pions/protons
• 100% muon beams in current simulations
• Varying emittances and amplitude distributions– Effect of the beam line varies with particle amplitude
• Using a ‘realistic’ beam from Kevin in current simulations
• Stochastic processes – ON/OFF in G4MICE
• Energy loss – ON/OFF in G4MICE
• Include detector performance?– Just MC– G4MICE TOF reconstructed space points
• Peculiar problems: >144 space points in TOF0!• Will be addressed by TofTrack Class work
– Progress may need to be post CM20 when Malcolm returns from Fermilab
Analysis Meeting – [email protected] – Slide 3
G4MICE: Stage 2 Volumes
25cm
50cm
75cm
-14m -6m-8m-10m-12m0cm
Active Area Tof-0 Cherenkov Active area Tof-1
75cm
40cm
20cm
70cm
1m 20cm 75cm
65cm
21cm20cm18cm
Upstream Shield
Q7 Q8 Q9
Special Virtual Planes
-14.55m-14.05m
-9.65m
5cm
-13.7m
-14.4m
-14.6m
-11.4m -7.9m-6.39m
-6.53m
-6.67m
25cm
Analysis Meeting – [email protected] – Slide 4
Scattering: ON, energy loss: ON Scattering: OFF, energy loss: ON
Scattering: ON, energy loss: OFF Scattering: OFF, energy loss: OFF
Analysis Meeting – [email protected] – Slide 4
Analysis Meeting – [email protected] – Slide 5
Scattering: ON, energy loss: ON Scattering: OFF, energy loss: ON
Scattering: ON, energy loss: OFF Scattering: OFF, energy loss: OFF
Analysis Meeting – [email protected] – Slide 5
Analysis Meeting – [email protected] – Slide 6
Scattering: ON, energy loss: ON Scattering: OFF, energy loss: ON
Scattering: ON, energy loss: OFF Scattering: OFF, energy loss: OFF
Analysis Meeting – [email protected] – Slide 6
Analysis Meeting – [email protected] – Slide 7
Energy loss and transmittance
Scattering: ON, energy
loss: ON
Scattering: OFF, energy
loss: ONScattering: ON, energy
loss: OFF
Scattering: OFF, energy
loss: OFF
All muonsOnly muons which get through TOF1
Analysis Meeting – [email protected] – Slide 10
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 – [email protected] – Slide 12
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 – [email protected] – Slide 14
Transverse phase space: horizontal
x / cmpx / MeV
-40 cm – 40 cm-100 MeV – 100 MeV
x
px
Analysis Meeting – [email protected] – Slide 15
Transverse phase space: vertical
y / cmpy / MeV
-40 cm – 40 cm-100 MeV – 100 MeV
y
py
Analysis Meeting – [email protected] – Slide 17
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
