Readiness for Step IV.0 (and onwards)

1. 1/11 Readiness for Step IV.0 (and onwards) Step IV.0 Step IV.1+ Step IV.0 analysis SS1, SS2 & FC map analysed and included in geometry Effect of reduced magnet currents studied Matched beams found and simulated Step IV.1+ run plans formed and simulated. • EMR analysis • Integration with Global PID? • Step IV.0 shakedown analysis • Make sure we’re ready to take data and do something with it before we run. • Step IV(.0+) analysis script storage • Ensure reproduction of analysis is possible • Best beam line settings found and simulated • Tracker (and general detector) alignment simulations ready • Analysis routines prepared • (Optional) Diffuser scattering feasibility study complete • (Optional) No-field multiple scattering feasibility study complete Step VVI • RF questions answered • Requires ‘experts’ from analysis group and RF group • Step V vs Step VI physics comparison (see later) • Plus, I expect, many more items from Step IV Need a in every box before we can say we’re ready!

2. 2/11 Step IV.0 Diffuser EMR SS1 FC SS2 B = 0 CKOVs 7.5—8m TOF0 TOF1 Tracker planes Empty absorber TOF2 KL • “Straight” tracks, diffuser open: Align experiment, check PID OK OK OK Not OK • Limitations and challenges: • Low particle rate • Tolerance to multiple scattering

3. 3/11 Reality probably not simple Bad x x x x OK? 1 x x x x x x x x x x x x x x x x x x x x x 2 x x x x x Bad 3 • 1. Muon hits outer diffuser and scatters into Hall. • Clearly a ‘bad’ muon • 2. Muon has small scatters in air/tracker volume, then larger scatters in absorber windows. • Scatters bring muon back to tracker volume #2 • Doesn’t help us align trackers, but would we realise that? • 3. Muon has small scatters at all components • Small overall effect (though distances are large)? • Limits ability to align detectors/reconstruct tracks • Input from tracker cosmic muon analysis? ? ? More from Melissa Uchida

4. 4/11 Alignment requirements Bad x x x x OK? 1 x x x x x x x x x x x x x x x x x x x x x 2 x x x x x Bad 3 OK? 4 • Particles! • Does species matter? Are decays useful for alignment (particle 4)? Is there a preferred momenta? • Ideally discard particles that hit diffuser (exterior) and magnets (best veto?) • Particle rate to EMR currently low (without DS) • Need to maximiseuseful particle rate through cooling channel • Requires G4BL or MAUS simulations to come up with Q4—9 magnet settings • Does depend on preferred particle species for alignment • Simulations! • Can’t turn off multiple scattering in the experiment: Need to understand it • Can’t mis-align/align parts of the tracker on purpose to understand our limits More from Melissa Uchida

5. 5/11 Alignment simulation requirements Bad x x x x OK? 1 x x x x x x x x x x x x x x x x x x x x x 2 x x x x x Bad 3 OK? 4 • Need Step IV geometry, with empty absorber and no magnetic fields, in MAUS • Need best Q4—9 settings to optimise beam down channel • Visualisation of simulations/tracks • With these... • Simulate the passage of an on-axis, paraxial (pure/mixed) muon/pion beam. Can use this to predict overall scale of multiple scattering interference in alignment • Simulate the optimised (pure/mixed) muon/pion beam through Step IV.0 with and without multiple scattering (and energy loss!) turned on. Compare overall scale of scattering with on-axis simulation. • Difference due to magnet body material etc. • With same input beam, fake a detector/tracker plane offset/rotation More from Melissa Uchida

6. 6/11 Alignment simulation requirements Optimising beam for Step IV.0 Simulating beam for Step IV.0 Take optimised G4BL settings and make a suitable input beam for MAUS Generate required on-axis beams for multiple scattering studies Use Step I data as a benchmark for the “worst case” scenario opposite Co-ordinate with G4BL optimisation • G4BL is our “traditional” beam optimising tool • What are the benefits over MAUS? • Need settings that maximise beam through an approx 0.4m diameter, 8m long cylinder • Risks: • Time consuming. Need answer sooner rather than later • May be no better than our existing beam settings! • Mitigation: • Divide beam line optimisation between different people (e.g. mu, pi, pz=200MeV, pz=240MeV) • Assume “standard” MICE beams and estimate transmission and time to gather data. Will this “worst case” scenario work? More from John Nugent Maria Leonova co-ordinating: volunteers needed!

7. 7/11 PID Tracker alignment requires PID PID requires tracker alignment Particle ID Analysis Software Which box? Both? This way up This way up • Important that we avoid this loop: Requires input from Ian Taylor/Celeste Pidcott

8. 8/11 Useful (to MICE) physics? 1) 2) • Step IV with fields beam matching relies on correct modelling of the diffuser • Measure multiple scattering through diffuser with first tracker? • Without diffuser, measure range of trajectories seen by tracker 1 • Add diffuser, range of trajectories should increase due to multiple scattering • Can compare overall measured angular distribution of tracks to simulation • Good enough to confirm Step IV (with field) beam settings? • Particle-by-particle is harder (Q789 between TOF0 and TOF1) • Could attempt to track particle (Rayner-like) between TOF0 and TOF1 and estimate its un-scattered trajectory*: • Measure trajectory in tracker 1: • Can make use of “bad” particles that cross the magnet material. • Requires beam time, otherwise synergises with tracker analysis... • Allows us to react to unexpected beam behaviour before Step IV.1 TBD (volunteers?) *There are several caveats to doing this...

9. 9/11 Step IV.1 is empty absorber + magnetic field Good preparation for Step IV.2 B != 0 Liquid hydrogen • Step IV.2 will use a liquid hydrogen absorber • Unlikely to have this possibility during Step IV.0 • One goal of Step IV.2 is to measure multiple scatteringdistributions as well as cooling • Why? Because we can and it hasn’t been done over the range of low-Z materials we have at our disposal! • Can measure multiple scattering in principle with fields on • Easier to measure with fields off • So measure multiple scattering before turning on field • E.g. Can do this during a shakedown run to test data taking and analysis routines still OK after long shutdown • Synergy with Step IV.0 data (this is the background scattering without liquid hydrogen) • Requires feasibility study... More from Ed Santos (?)

10. 10/11 Draft Step IV.0 run plan • Survey TOFs/Ckovs/Magnets/EMR • Trackers inside SS1 and SS2, surveyed w.r.t. magnets • Use optimised currents in Q4—9 • Need list of settings for muon and pion beams • Also need best proton absorber settings • Check expected particle rate vs. actual particle rate seen in all detectors. • Calibrate TOFs (EMR?) • Collect X particle triggers per beam setting • X must be determined prior to running • Gives estimate of shift time and/or number of shifts required • On-the-run analysis (if we see something unexpected, what do we do about it?) We must fill in this table (and have simulated all entries):

11. 11/11 One final, important, thing... • Step V vs. Step VI • In addition to RF-related analysis questions • PRY needs modifying for each MICE Step • If we only get one choice, which Step would give us the best physics (and by what margin) • Need to start simulating Steps V and VI and making the comparison. We must have this in hand by CM38! • Worry #1: This must not interfere with our efforts for Step IV • Worry #2: Can we simulate this yet? Analysis Step V Step VI