Beam line characterization with the TOFs1 Demonstrating the emittance-momentum matrix Mark Rayner,...
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Transcript of Beam line characterization with the TOFs1 Demonstrating the emittance-momentum matrix Mark Rayner,...
Beam line characterization with the TOFs 1
Demonstrating the emittance-momentum matrixMark Rayner, CM26 California, 24 March 2010
3 6 10
140
200
240
Initial 4D N (mm)
Abs
orbe
r pz (
MeV
/c)
Cooling
channel
Q1 Q2 Q3 Q4 Q5 Q6 Q7 Q8 Q9DK sol D2D1
TOF1TOF0Target
Diffuser
GVA1 BPM1
,
1 2
Diffuser
t
Beam line characterization with the TOFs 2
Introduction Purpose of the beam line:
Generate the emittance-momentum matrix elements in pion muon decay beam lines
(3, 6, 10) mm (140, 200, 240) MeV/c
Data taking in December 6 mm – 200 MeV/c element
Runs 1380 – 1393, Kevin Tilley’s optics, 6k target pulses 6 mm – 140 MeV/c element
Runs 1409 – 1411, KT’s optics re-scaled to the new momentum, 2k target pulses
Phase space reconstruction by TOF0 and TOF1 Longitudinal momentum resolution O(5 MeV/c) Transverse position resolution O(2 cm) Transverse momentum resolution O(px
max/70)
Dependent on pxmax, the maximum un-scraped momentum of the optics in
question
Comparison with Monte Carlo simulations The 6-200 element has been simulated using G4BeamLine and G4MICE
This talk Reconstruction algorithm Distributions, means, covariance matrices, and emittances for 6-140 and 6-200 data
Analysis talk on Friday What this means for future stages in MICE
Beam line characterization with the TOFs 3
Selection of the muon peak
6-200
6-140
Intermediate
momentum
Beam line characterization with the TOFs 4
Reconstruction procedure
Estimate the momentum
p/E = S/t
Calculate the transfer matrix
Deduce (x’, y’) at TOF1 from (x, y) at TOF0
Deduce (x’, y’) at TOF0 from (x, y) at TOF1
Assume the path length S zTOF1 – zTOF0
s leff + F + D
Track through through each quad,
and calculate
Add up the total pathS = s7 + s8 + s9 + drifts
Q5 Q6 Q7 Q8 Q9
TOF1TOF0
zTOF1 – zTOF0 = 8 m
Beam line characterization with the TOFs 5
Momentum reconstruction: 6-200 simulation
Path length
!
Measuring path length removes the bias on the momentum measurement
Beam line characterization with the TOFs 6
Simulation/data comparison at TOF1 (6-200 matrix element)
This simulation uses the geometry from before TOF1
was moved z = – 16.7 cm = – 0.56 ns / c
Muon time of flight Muon momentum
Beam line characterization with the TOFs 7
6-140 (x, px, y, py, pz) in mm and MeV/c
4296-509.0 132.3-20.37 5.77 4451-5.34 1.32 168.8 15.13-438.7 55.8 -7.03 13.65 1286
30.08 -8.49 14.085 0.136 212.8
x RMS normalized phase emittance = 5.30 mmy RMS normalized phase emittance = 1.78 mmTransverse 4d RMS normalized phase emittance = 3.07 mm
Covariance matrix
Means
Beam line characterization with the TOFs 8
6-200 (x, px, y, py, pz) in mm and MeV/c
3359-610.0 205.818.99 -17.68 36001.17 -1.61 82.3 17.43-107.6 -5.0 -5.84 11.81 602
16.64 -12.09 15.311 -0.407 258.1
x RMS normalized phase emittance = 5.37 mmy RMS normalized phase emittance = 2.25 mmTransverse 4d RMS normalized phase emittance = 3.48 mm
Covariance matrix
Means
Beam line characterization with the TOFs 16
Conclusion 6-200 element
Trace space beam properties required at TOF1 (6-200) <pz> = 261.8 MeV/c, x = 2.55 mm, y = 1.12 mm, and 4D N = 1.69 mm Takes into account binning effects
Trace space beam properties measured at TOF1 (6-200) <pz> = 258.1 MeV/c, x = 2.31 mm, y = 0.93 mm, and 4D N = 1.47 mm
Phase space beam properties measured at TOF1 (6-200) <pz> = 258.6 MeV/c, x = 5.37 mm, y = 2.25 mm, and 4D N = 3.48 mm
Phase space beam properties measured at TOF1 (6-140) <pz> = 212.8 MeV/c, x = 5.30 mm, y = 1.78 mm, and 4D N = 3.07 mm
Analysis talk on Friday Simulation: how would these beams behave in Stage 6? What about time?
Suggestion for the future data shifts Observe >40k muons (~6k target pulses?) for each of the nine
elements Kevin Tilley’s re-scaled 6-200 optics Optics derived from Marco’s genetic algorithm