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

CM23 Harbin January 2009 TOF Emittance Measurement 3

Pions from 13th December

CM23 Harbin January 2009 TOF Emittance Measurement 4

Positrons from 13th December

CM23 Harbin January 2009 TOF Emittance Measurement 5

Cable Length Calibration (0,1)

CM23 Harbin January 2009 TOF Emittance Measurement 6

Cable Length Calibration (0,0)

CM23 Harbin January 2009 TOF Emittance Measurement 7

Cable Length Calibration (1,0)

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Cable Length Calibration (1,1)

CM23 Harbin January 2009 TOF Emittance Measurement 9

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

CM23 Harbin January 2009 TOF Emittance Measurement 12

+

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

CM23 Harbin January 2009 TOF Emittance Measurement 13

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