simulated real beam into simulated mice1 mark rayner cm26
Post on 21-Dec-2015
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Simulated real beam into simulated MICE 1
Simulated real beam into simulated MICE
Mark RaynerCM26
Simulated real beam into simulated MICE 2
Introduction
Various fancy reweighting schemes have been proposed But how would the raw beam fare in Stage 6?
TOF0 measures px and py at TOF1 given quadrupole field maps On Wednesday I described the measurement of a 5D covariance matrix
(x,px,y,py,pz)
In this talk, compare two monochromatic 6-200 beams in Stage 6 A matched beam in the tracker A measured beam at TOF1
Measured (x, px) and (y, py) covariances No dispersion
Simulated real beam into simulated MICE 3
Time in MICE
RF frequency = 200 MHz, period = 5 ns Neutrino factory beam
Time spread is approximately 500 ps Want < 50 ps resolution in cavities
Possible methods for tracking time from TOF1 to the upstream tracker Use of the adiabatic invariant pperp
2/Bz0 The flux enclosed by the orbit of a charged particle in an adiabatically
changing magnetic field is constant Use of the linear transfer matrix for solenoidal fields
Multiply matrices corresponding to slices with varying Bz0 and kappa
Tracking step-wise through a field map Measured or calculated?
A Kalman filter Implemented between the trackers Static fields
None of these methods is particularly difficult Nevertheless, there is merit in simplicity This talk will investigate the first approach
Is pperp2/Bz0 really an adiabatic invariant in the MICE Stage 6 fields?
Simulated real beam into simulated MICE 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
Simulated real beam into simulated MICE 5
B field and beta lattice
matched in tracker
abs = 42cm
Simulated real beam into simulated MICE 6
Matched beam
Simulated real beam into simulated MICE 7
Beam 1
Beam 1: Runs 1380 – 1393 Kevin’s optics 6 mm – 200 MeV/c emittance-momentum matrix element Analysis with TOF0 and TOF1 – the beam just before TOF1:
Covariances: sigma(xpx) = –610 mm MeV
sigma(ypy) = +85 mm MeV
Longitudinal momentum Min. ionising energy loss in TOF1 = 10.12 MeV pz before 7.5 mm diffuser (6-200 matrix element) = 218 MeV [Marco] RF cavities have gradient 9.1 MV/m and 90 degree phase for the reference muon Start with pz = N(230, 0.1) MeV before TOF1, centred beam, transverse optics as
above
Simulated real beam into simulated MICE 8
Measured beam
Simulated real beam into simulated MICE 9
Matching time in the first cavity
Sigma pz = 24.5 MeV Beta = 0.857 to 0.904 (-1 to +1) Time over L = 17.2 ns to 16.3 ns
Difference = 0.89 ns RF period = 5 ns
Transfer matrix:
Work the covariance matrix back from the 1st RF to before the TOF:
L/Eref = 4423 mm / (230 MeV * 300 mm/ns) = 0.064 ns/MeV Sigma t RF = 500 ps Sigma t = sqrt( (0.5 ns)**2 + (1.568 ns)**2 ) = 1.645 ns Cov(t,pz) = –38.42 ns MeV
Simulated real beam into simulated MICE 10
Conclusion