Analysis meeting: Beam momentum measurements using TOFs Tuesday, 22 January 2008 Slide 1 of 10 Beam momentum measurement using TOFs: progress report Analysis meeting, 22 January 2008 Mark Rayner – Oxford/RAL

Analysis meeting: Beam momentum measurements using TOFs Tuesday, 22 January 2008 Slide 2 of 10 Beam parameters at Tof-0 MICE Beam Line Design, Kevin Tilley, 16-XI-07 Kevin’s realistic TURTLE beam of muons has been propagated starting at TOF0 by the G4MICE simulation code

Analysis meeting: Beam momentum measurements using TOFs Tuesday, 22 January 2008 Slide 3 of 10 Stage 2 G4MICE simulation 100 muons from Kevin’s realistic TURTLE beam:100 muons from Kevin’s realistic TURTLE beam: –Blue – positively charged particles, mainly mu+ –Red – negatively charged particles, mainly e- –Green – neutral particles, mainly photons TOF0 Cherenkov Q7 Q8 Q9 TOF1 Tracker 1

Analysis meeting: Beam momentum measurements using TOFs Tuesday, 22 January 2008 Slide 4 of 10 TOF0 & Cherenkov

Analysis meeting: Beam momentum measurements using TOFs Tuesday, 22 January 2008 Slide 5 of 10 Quadrupoles 7, 8 and 9

Analysis meeting: Beam momentum measurements using TOFs Tuesday, 22 January 2008 Slide 6 of 10 TOF1 & Tracker 1

Analysis meeting: Beam momentum measurements using TOFs Tuesday, 22 January 2008 Slide 7 of 10 Amplitude analysis of muons surviving to TOF1

Analysis meeting: Beam momentum measurements using TOFs Tuesday, 22 January 2008 Slide 8 of 10 Momentum reconstruction Reconstruction class TofTrack being added to G4MICE –In close collaboration with Malcolm –Very simple to begin with –Designed to be useful before trackers are operating –Details to follow at CM20 –The following work is a look beyond that at the difficulties of doing something more sophisticated The following numbers are Monte Carlo truth… –Designed to illustrate the intrinsic difficulties in reconstructing momentum given TOF0 and TOF1 data No time measurement error No transverse position measurement error Neglect corner clippers –Use hit with most photoelectrons

Analysis meeting: Beam momentum measurements using TOFs Tuesday, 22 January 2008 Slide 9 of 10 Path between Tof-0 and Tof m Tof-1 (same design for Tof-2) Tof m Actual path Straight line between space points Straight line between Tof centres muons r 0 =(t 0, x 0, y 0,z 0 )| MC  r  | =  {(x 1 -x 0 ) 2 +(y 1 -y 0 ) 2 } Some definitions: p MC TOF1 P crude guess = |  m  where  = (r 1 -r 0 )/[(t 1 -t 0 )c] p MC TOF1 p Crude guess Correction factor = r 1 =(t 1, x 1, y 1,z 1 )| MC

Analysis meeting: Beam momentum measurements using TOFs Tuesday, 22 January 2008 Slide 10 of 10 Prospects for momentum reconstruction

Analysis meeting: Beam momentum measurements using TOFs Tuesday, 22 January 2008 Slide 11 of 10 Extra Slides

Analysis meeting: Beam momentum measurements using TOFs Tuesday, 22 January 2008 Slide 12 of 10 Transverse phase space: horizontal x / cm px / MeV -40 cm – 40 cm -100 MeV – 100 MeV x px

Analysis meeting: Beam momentum measurements using TOFs Tuesday, 22 January 2008 Slide 13 of 10 Transverse phase space: vertical y / cm py / MeV -40 cm – 40 cm -100 MeV – 100 MeV y py

Analysis meeting: Beam momentum measurements using TOFs Tuesday, 22 January 2008 Slide 14 of 10 Longitudinal phase space

Analysis meeting: Beam momentum measurements using TOFs Tuesday, 22 January 2008 Slide 15 of 10 Momentum measurement uncertainty p =  m 0 c –assume PID ascertains m 0 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  t1–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