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 9

Momentum

Beam line characterization with the TOFs 10

Horizontal phase space

3 fit

Beam line characterization with the TOFs 11

Vertical phase space

Beam line characterization with the TOFs 12

Horizontal spatial dispersion

Beam line characterization with the TOFs 13

Horizontal momentum dispersion

Beam line characterization with the TOFs 14

Vertical spatial dispersion

Beam line characterization with the TOFs 15

Vertical momentum dispersion

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