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MICE Beamline: Plans for initial commissioning.

Kevin Tilley, 16th November. - 75days until commissioning

• Target, detectors, particle production

• Upstream beamline

• Downstream beamline:

•Step 1 Jan 20 - March , Step 2 April – June.

• Summary

(& 9hours)

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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.

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Beamline layout & diagnostic devices

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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.

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Step1:- Beamline optics commissioning

Optics goals: Step1 (Jan-March):

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

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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.

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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)

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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

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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.

Q1'

Q2'

Q3'

IWin

AIR

BWin

USDW

Q1'

Q2'

Q3'

IWin

AIR

BWin

USDW

Goal:- Maximum pion flux at detector D1, on axis & aligned pion beam. Minimum pion spot size to aid collimation.

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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.

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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)

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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

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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

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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.

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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