CM23 Harbin January 2009 TOF Emittance Measurement 1
Beam Characterization with the TOFs
Mark Rayner
CM23 Harbin
CM23 Harbin January 2009 TOF Emittance Measurement 2
Saturday 13th December Shiftrun # 850 - 854 855 856 - 858 860 865 - 871
pions protons positrons
D2 MeV/c 431 490 130 200 various?
TOF0 MeV/c 420 417 100 150
current Q1 91.8 101.2 25.5 37.4 various?
A Q2 168 185.1 46.5 68.2
Q3 102.8 113 28.3 41.6
D1 345.6 390.4 89.7 130
D2 158.5 171.1 43.6 63.5
Q4 283.7 299.9 72.6 107.8
Q5 380 398.4 96.2 143
Q6 252.1 262.1 63 93.9
Q7 263.4 0 38.4 63.1
Q8 398.8 0 57.7 95.1
Q9 340.9 0 48.8 80.6
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Pions from 13th December
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Positrons from 13th December
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Cable Length Calibration (0,1)
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Cable Length Calibration (0,0)
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Cable Length Calibration (1,0)
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Cable Length Calibration (1,1)
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TOF0—TOF1
Time of flight (ns)
calibration…Mean=8m/30cm ns – t
various p, >200, =1 150ps resolutionneed timewalk correction (and more data!)
e+
‘420MeV/c +’
Transverse momentum (MeV/c)
p=30MeV/c
mainly muonsamplitude 15.2sigma 157ps
mainly pionsamplitude 50.0sigma 196ps
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TOF & Momentum
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+
TOF0 x (mm)
TOF1 x (mm) TOF1 y (mm)
TOF0 y (mm)
TO
F0
dx/d
zT
OF
1 dx
/dz
TO
F1
dy/d
zT
OF
0 dy
/dz
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+
TOF0 x (mm)
TOF1 x (mm) TOF1 y (mm)
TOF0 y (mm)
TO
F0
dx/d
zT
OF
1 dx
/dz
TO
F1
dy/d
zT
OF
0 dy
/dz
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TOF Beam Charzn Summary● All the tools required for…
■ Space point/time-of-flight/momentum reconstruction at a glance
■ Calibrating the TOFs for cable length and testing this calibration
■ Measuring emittance
● …are uploaded to G4MICE and easy to use – see software talk● DAQ and TOF guys are encountering and solving lots of problems● 150 ps time-of-flight resolution due to lack of e+ and time-walk corr.● Momentum measured, dipole spread >20% confirmed● Trace space reconstructed. Next:
■ Bin carefully, and calculate emittance/optical functions
■ Error analysis
■ Re-examine MCs
■ Take into account emittance growth in Cherenkov