Beam momentum measurement using TOFs: progress report

Beam momentum measurement using TOFs: progress report Analysis Meeting, February 2008 Mark Rayner – Oxford/RAL

Beams/scenarios to investigate • Particle composition of beam • Muons/pions/protons • 100% muon beams in current simulations • Varying emittances and amplitude distributions • Effect of the beam line varies with particle amplitude • Using a ‘realistic’ beam from Kevin in current simulations • Stochastic processes • ON/OFF in G4MICE • Energy loss • ON/OFF in G4MICE • Include detector performance? • Just MC • G4MICE TOF reconstructed space points • Peculiar problems: >144 space points in TOF0! • Will be addressed by TofTrack Class work • Progress may need to be post CM20 when Malcolm returns from Fermilab

Special Virtual Planes G4MICE: Stage 2 Volumes 25cm 75cm 75cm 20cm 1m 75cm Upstream Shield 65cm 50cm 70cm 40cm 5cm 25cm 21cm 20cm 20cm 18cm -6.53m Q7 Q8 Q9 -14.4m -14.05m -6.39m -6.67m -11.4m -7.9m -9.65m -14.55m -13.7m -14.6m 0cm -14m -6m -12m -10m -8m Active Area Tof-0CherenkovActive area Tof-1

Scattering: ON, energy loss: ON Scattering: OFF, energy loss: ON Scattering: ON, energy loss: OFF Scattering: OFF, energy loss: OFF Analysis Meeting – m.rayner@physics.ox.ac.uk – Slide 4

Scattering: ON, energy loss: ON Scattering: OFF, energy loss: ON Scattering: ON, energy loss: OFF Scattering: OFF, energy loss: OFF All muons Only muons which get through TOF1 Energy loss and transmittance

P_estimated [MeV]

Extra Slides

MICE Beam Line Design, Kevin Tilley, 16-XI-07 Beam parameters at Tof-0 Kevin’s realistic TURTLE beam of muons has been propagated starting at TOF0 by the G4MICE simulation code

Amplitude analysis of muons surviving to TOF1

0.48 m 0.48 m MC p TOF1 muons MC p TOF1 Tof-0 Path between Tof-0 and Tof-1 r1=(t1, x1, y1,z1)|MC Some definitions: Pcrude guess= |b| g mm where b = (r1-r0)/[(t1-t0)c] |Dr^| = Ö{(x1-x0)2+(y1-y0)2} r0=(t0, x0, y0,z0)|MC Straight line between space points Straight line between Tof centres Actual path Tof-1 (same design for Tof-2) Crude guess p Correction factor =

Prospects for momentum reconstruction

Transverse phase space: horizontal x px px / MeV -100 MeV – 100 MeV x / cm -40 cm – 40 cm

Transverse phase space: vertical y py py / MeV -100 MeV – 100 MeV y / cm -40 cm – 40 cm

Longitudinal phase space

Momentum measurement uncertainty • p = b g(b) m0 c • assume PID ascertains m0 • Timing uncertainty • Technical challenge: progress being made in Milano • One counter = scintillator with 2 PMTs • “…a conservative request for single counters timing resolution is 60–70 ps” • MICE Note 145 • Other factors: • 2 planes per station • Rotated so as to yield ‘space points’ • Multiple space points per muon possible/likely • st1–t0 will be larger still • Path length uncertainty • Software challenge: challenges remain… • Multiple scattering in Tof-0, Cerenkov, Tof-1 and air • Focusing in quadrupoles Q7, Q8 and Q9 • Limited transverse position resolution

Beam momentum measurement using TOFs: progress report