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

2 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 3 Beamline layout & diagnostic devices

4 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 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 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 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 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 9 Step1:- Upstream beamline optics 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. Goal:- Maximum pion flux at detector D1, on axis & aligned pion beam. Minimum pion spot size to aid collimation.

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 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) Goal: Verify can achieve approximately right beamsizes & waists at MICE. Ensure reasonable transmission & flux. Measure alignment

13 Step1:- Downstream beamline optics 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. Goal: Verify can achieve approximately right beamsizes & waists at MICE. Ensure reasonable transmission & flux. Measure alignment

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

15 Summary 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. Goal: Verify can achieve approximately right beamsizes & waists at MICE. Ensure reasonable transmission & flux. Measure alignment