MICE Beamline: Plans for initial commissioning.

1. MICE Beamline: Plans for initial commissioning. • Target, detectors, particle production • Upstream beamline • Downstream beamline: • Step 1 Jan 20 - March , Step 2 April – June. • Summary Kevin Tilley, 16th November. - 75days until commissioning (& 9hours)

2. Charge. Meaning in commissioning…. Optics goals: Step1 (Jan-March): Verify can achieve approximately right beamsizes & waists at MICE. Ensure reasonable transmission & flux. Measure alignment. Optics goals: Step 2 (April–June): Match beam with diffuser. Find & demonstrate (ε,p) beam cases. Demonstrate purity.

3. Beamline layout & diagnostic devices

4. First things first – target, detectors, particle production • Target • Has the target got the required acceleration? • Insert target shallow dip depth, measure reproducibility/flux/loss reproducibility • Insert target into towards 38mm if ISIS beam loss ok, or else acceptable loss. • MICE & Beamline Detectors • Target in, only dipoles on, P(B1=B2)=350MeV/c. Negative polarity (pi-) Calibrate detectors • Particle production • with only dipoles on, P(B1=B2), characterise pion flux versus momentum • relatively simple with MICE PIDs. • ….useful for extrapolating to expected rates.

5. Step1:- Beamline optics commissioning Optics goals: Step1 (Jan-March): Verify can achieve approximately right beamsizes & waists at MICE. Ensure reasonable transmission & flux. Measure alignment.

6. Step1:- Upstream beamline optics • Upstream goal:- • Maximum pion flux at detector D1, on axis & aligned pion beam. (=max muon flux, on axis & aligned muon beam. Slightly open question = to confirm this equivalence?) Minimum pion spot size to aid collimation.

7. Step1:- Upstream beamline optics • Basic optics checks … … (1/2) • Set P(B1=B2) = design setting 444.7MeV/c. • Check basic optics of Q1-Q3. (compare to model) • Individual quads fields scanned:- - measure beamsize changes at U1,D1 - fit to Q1 effective length? - measure beam centroid changes at U1,D1 - fit to any residual target misalignment • Alternatively fields fixed, Target dip change. • - measure beam centroid changes at U1,D1 - refit to any residual target misalignment • Open question:- can beamsize changes & centre changes be seen U1/D1 (strong vert focussing B1, distance to D1)

8. Step1:- Upstream beamline optics • Basic optics checks………. (2/2) • Set Q1,Q2,Q3, Decay solenoid design optic. • Set P(B1=B2) • Check basic optics of Decay Solenoid:- • Ramp field (beam phase advance), measure beamsize at D1

9. Step1:- Upstream beamline optics Goal:- Maximum pion flux at detector D1, on axis & aligned pion beam. Minimum pion spot size to aid collimation. • Optimise:- • Set all fields to design settings. P(B2=B1) • Optimisation methods:- 1. Scale (Q1,Q2,Q3) as a single unit, & decay solenoid as a single unit. example:-scaling Q1-Q3 single unit:- 2. Decouple & optimise eg Q1. Optimise 3 parameters:-((Q1,(Q2,Q3),Decay solenoid) 3. Further free up parameters & optimise.

10. Step1:- Downstream beamline optics • Downstream Goal:- • (Goal of Step1) Verify can achieve approximately right beamsizes & waists at MICE. Ensure reasonable transmission & flux. Measure alignment. • Suggest aim at just one case initially ~(6pi,200MeV/c) Open question: is setting up the downstream beamline with pions of benefit to us? Advantages, but in extreme: are optics for pions suitable for muons? (simulation question) Default is currently to setup beamline with muons until understood.

11. Step 1:- Downstream beamline optics • Basic optics checks:- (1/1) • B2 scan – backward/forward muon momentum edges. • Basic quadrupole optics – quads in triplets • Open question: has TOF0, TOF1 or Tracker sufficient resolution – with sensible rates? • Use beam monitor as a fallback if not. • Beam misalignment check, by scanning quads fields (near reasonable focus)

12. Step 1:- Downstream beamline optics Goal: Verify can achieve approximately right beamsizes & waists at MICE. Ensure reasonable transmission & flux. Measure alignment • Measurements:- • Set downstream beamline to have design optics. • Confirm beamsizes at MICE approximately correct. • Measure misalignment at Tracker • Measure transmission efficiency D1- Tracker. • Measure natural emittance of beamline : • (for feeding back to calculate required alpha/beta). • Use 3 tracker planes & TOF assuming muons form 97%, to make offline momentum cuts. • Recalculate desired beamsizes/waists. • Attempt to obtain desired beamsizes/waist… (PTO)

13. Step1:- Downstream beamline optics Goal: Verify can achieve approximately right beamsizes & waists at MICE. Ensure reasonable transmission & flux. Measure alignment • Optimise :- (Attempting to obtain desired beamsizes/waist) • Optimisation techniques for optimising beamsize/waist in Tracker:- • (some are open questions to answer efficacy) • By hand single lens scaling of (Q456) / (Q789), then decouple in stages. • TRANSPORT envelope fitting: measure beam at Tracker, use known Q789 settings,TOF0 beamsize -> determine input beam at TOF0 -> solve for Q789 for 3-rqd parameters at MICE. • Construct empirical response matrix (in quantites to be determined) and solve for Q4-Q6. • Optimiser .

14. Step2 – Downstream optics Optics goals: Step 2 (April–June): Match beam with diffuser. Find & demonstrate (ε,p) beam cases. Demonstrate purity. • Similar optimisation techniques to previous slide. .

15. Summary Goal: Verify can achieve approximately right beamsizes & waists at MICE. Ensure reasonable transmission & flux. Measure alignment • Goals for Step 1 commissioning: proposed • Do upstream optics separately. Sub-goal proposed. • Basic optics • Optimisation • Do downstream separately. Sub-goal proposed. • Basic optics • Optimisation • Goals for Step 2: proposed Goal:- Match beam with diffuser. Find & demonstrate (ε,p) beam cases. Demonstrate purity. • Optimisation of downstream section uses similar techniques to Step1.