Beam line commissioning Preparations for Phase1 Kevin Tilley For Paul Drumm & the beam line group

Definition of Stages ● pre-commissioning checks – as soon as kit arrives – limited – avoid later duplication (risk) ● Magnet Commissioning – starts when the magnets are installed & services complete. ( all the above for Q1-3, B1, Q4-6 need to be done by 1 st Aug (“vault”/ &<shielding). Q7-9 clearly also preferably so. ) ● Online Commissioning (pre-Phase 1) – (target commissioning) – beam in beamline ● Hand over to MICE commissioning (Phase1) – who has responsibility & directs work. what personnel? – need to define this point

Precommissioning checks ● Power supplies – all supplies logically identical – three small supplies for Q1-3 grouped  test bed – exercise power supply controls & interlocks (afap) ● Q35 magnets – coil checks (electrical insulation) ● Dipoles & Quads – install. power supply software control & monitoring of power supplies etc. – cooling: flow switches and temp sensors ● Decay Solenoid – plans covered elsewhere (‘Status of PSI Solenoid’ talk) can start magnet field checks proper …

Conv. Magnet Commissioning…. ● important measurements: ● polarities of magnets ● current to field relationship (“linearity plot”) ● magnetic alignment: need simple tools to check field centres; ● ideal measurements: ● field quality/uniformity ● effective length note we are not over rich with people to do this!

Quad/Dipole magnetic fields ● Cartoon of Hall-probe support: – eg. for Quads: “target” to sit in quad/dipole aperture Array of predetermined positions: eg 5: geometric centre geometric centre +/- x0 geometric centre +/-y0 drop in hall probe magnetic centre:- geometric ctr geometric ctr +/-x0/y0 current to field relationship:- geometric ctr –x0 say. By = - g. x0 -> extract ‘g’ versus I ● for Quads: need 1xQIV support, 1xQ35 support ● similar for Dipoles: need 1xM1 support.

Decay Solenoid magnetic field? - should we have a go at this? - field polarity not important. – not aware of a method to quantify the field strength – estimation from fringe field?

On-line commissioning – pre-Phase1 Rough outline of ISIS startup. Intermittent, base rate beam in Synchrotron ideally > ~10/08

● with beam in ISIS synchrotron (>~10/08?): ● MICE target mechanical etc commissioning ● particle production measurements from target? (à la Oct06?) On-line commissioning – pre-Phase1

● With the target operating: (~ mid Aug –> Step1?) ● thread beam through each beam element to the end. – here there is overlap with ABl CM17 proposals for Step 1 – In August, can begin working to establish beam properties:- – beam present / fluxes / alignment thru the beamline to the end. – more complex measurements if TOFs/Ckov/tracker are available. – Follow beam thru each element, but I’d propose emphasis for August = spend time on the upstream end ie: Q1 -> B2 (-> Q6?) (measuring/realigning). These areas become more difficult to get access to as ISIS continues to startup. – then we can go onto Q6 -> Q9 when done & then into Step 1 (Ideas for) On-line commissioning – pre-Phase1

● With the target operating: (~ mid Aug-> Step1?) ● take beam through element by element – one at a time and in down-stream order – to establish that (with nom field values) ● the beam is present at the exit of the beam element ● fluxes are approximately as expected ● establish alignment is OK :--- – need upstream collimation to do in each case:- – ideally vary each quad & measure following to ascert alignment – realign if necessary – vary dipole to ascertain alignment of dipoles. – realign if necessary ● Make basic to the end of Q9 & to MICE position (Ideas for) On-line commissioning – pre-Phase1

Beam Diagnostics ● Simple diagnostics are required – Polaroid film (all beam – protons(C2H4?)) – Simple “paddle” scintillation detector (all beam – protons(C2H4?)) ● More sophistication – Multi-fibre monitoring (all beam – protons(C2H4?)) ● Even more sophistication (these will give us the real beam of interest……….) – ToF – Ckov – Tracker (w/out solenoid) – Tracker (with solenoid)

● When the beam line is established to be in a robust state …

MICE Commissioning (Phase1) ● more detailed setup & performance measurements (AB CM17 talk….) I have only one additional point to make against this: re: first idea of making beamsize / position tuning.

Beam tuning: eg. beamsizes ● Someone has 6 simultaneous equations to solve on the spot ! (Q4-9) ● It would be very useful to develop practical beam software to aid tuning Q4-9 for beamwidths / match. (for step 1 & esp 2). Design codes presently too slow / inadequate. ● We’d need: ● the underlying beam model software: – quick / represents beamline accurately & can solve. ● provision to make special measurements (ie. the input beam?) ● software telling us beam data downstream from TOF0 /1 / Tracker ie. sizes p0. ie. sizes (centres) of “Good p0

‘Philosophy’; example for beamwidths:  Obtain measurements initial beam at entry (α, β, ε).  Use together with measurements eg profile monitor beam widths : to fit model to machine. (fit quad fields)  Now have a model of the real machine.  Now specify desired profile / beamsizes eg. at tracker  Solve model for changes to quad fields for this.  Apply Δk ( new param – model param) to machine  Iterate process if necessary Requires measurement or some estimate of α, β, ε at entry. In our case is the & subset which reaches end. One off Measure via TOFs: slideable TOF0 for profiles < Q4? Requires a model of machine which can optimise / solve for changes QUICKLY. What code could represent muon tpt well & solve quickly? (Transport? no? MAD? No? our tracking codes: G4BL/ICOOL/TTL? no? We have a need here in common with design optimisation

EPB + Target end Measurement of input beam:- 3 profile monitors in a drift. -> alpha, beta, emittance Actual measurements of beam through channel and at end. Model of beamline which can fit to measured beam & solve for required end

Idea for Input Beam Measurement Slideable TOF0 at 3 positions: Measurement of α, β, ε at entry for p0 “Good muons” beam via 3 positions of TOF0. Provides measurement of x,x’y,y’ also TOF1 Proposed as a ~ one-off measurement