paul drumm, mutac jan Precursor: - Resources since cm16. Beamline Review Response. Optics related work: the major threads: -Current (ε,p) status - Current (ε,p )optics design work (i) & (ii) - Beam steering/correction -Collimation d/stream & upstream. - Diffuser status (briefly) Beamline commissioning/diagnostics Prioritised Work plan towards August/September Status of Beamline Design K. Tilley, RAL, 01/02/07

paul drumm, mutac jan Since CM16 : Nov / Dec:- Marginal time to progress. 2x meetings, 'some' work recommenced - due ISIS pressures & no change in resource (KT) Jan:- ~ normal strength + new Brunel postdoc (50%) + (small%) IIT postdoc butminus much of TJR, CR, KW Its clear that there is also a lot of outstanding work desired by August/September & "not much of us". We are drawing up a workplan of what we could realistically achieve to be discussed with MICE. Precursor:

paul drumm, mutac jan Beamline Review - Response completed 6 points made by reviewers. We've responded to these, and forwarded the response on for consideration.

paul drumm, mutac jan Current (ε,p) Beamline Cases Current lattices are as per CM16:- MeV/c (Two rows really here: For Fixed & Scaled Tracker fields ) TT: Transport & Turtle G4: G4Beamline (incl new Ckv1) pp 11 66 10  TT G4BL TT G4BL TT G4BL 140 … with the same "+'s" and -'s as that time. ie '6pi' assess' to ~ 10pi in G4BL etc. NB: some potential for assessing how coolable/useful these beams actually are.

paul drumm, mutac jan Current (ε,p) Optics design work We are focussing on the 'baseline' case, to try and optimise this. -> a 'real' matched 6pi beam. Two (present) approaches: (i) G4BL internal optimiser (TJR/DH) (ii) Addressing Tpt/Ttl weakness' -> re-evaluate in G4BL (KT/HN/CR/KW) MeV/c pp 11 66 10  TT G4BL TT G4BL TT G4BL 140

paul drumm, mutac jan G4BL beam profile visualisation tool complete. - Interface for MINUIT which can vary Q4-9 fields & Diffuser thickness - Work to optimise for emittance & match - Some interesting results w/o TOF0 & without air (helium) - Limited TJR/DH time for MICE - Computing power needed is quite vast to acquire reliable data ! - Ongoing. - Maybe something which should also be picked up by others? - (limited by people time / computing power). - (A final 'exact' beamline (6pi,200 etc) will probably need to be done internally via G4BL anyway) (i) G4BL optimiser (TJR/KW)

paul drumm, mutac jan A number of weakness of Tpt/Ttl model for this beamline are well known: (1) lack of spectrometer solenoid fringe field (2) No Air. Many materials have √θ 2 ttl ~ 0.7 √θ 2 g4bl - hopefully these were important: we can "fix" these - Also, can study g4bl versus Turtle beam & try to glean other significant differences:- (ii) Addressing Tpt/Ttl weakness' -> re-evaluate in G4BL It's now clear why ε g4bl >> ε ttl: ε ~ Δx.Δx': - Δx. g4bl >> Δx. g4bl Δx': g4bl ≈ Δx'. ttl The cause for Δx g4bl maybe due to above (1,2) but should be found from studying the output differences?

paul drumm, mutac jan This work has just seriously begun within last ~ 2weeks. - We will design Turtle beam for new match point (outside of ss fringe field) - We will (probably) refine our model of beamline materials (Air etc.) - Incorporate other significant effects that we have time to find. - We can also consider other things which may be useful to beamline design - moving Q7,8,9 downstream a little - moving Ckov1 near to upstream of Q7?? * - May not be easy. The "notional" timescale is to aim towards completing by CM17 - but it depends on how accurate this process is wanted to be….?? (ii) Addressing Tpt/Ttl weakness' -> re-evaluate in G4BL ctd

paul drumm, mutac jan Beam Steering/Correction Scheme Current baseline is still as per CM14/Osaka:- Lattice dipoles and quads impede optimal placement. Best fit solution is: B2 VSM1 CKV1 VSM2 HSM1 Q4-6 Q7-9 TOF0 TOF1 (some) Issues:- - have realistic magnet misalignments been studied? - use of 3 SMgts + B2 to perform correction (B2 used for p0 selection) so quantitatively, what is the effect on end? - Space provision: VSM1 position may sit on Cllmtr ! - will biased quadrupoles suffice? - we're currently not planning for SMgts on day 1 ISIS TS2 steering magnet

paul drumm, mutac jan Collimation upstream & downstream TOF0 rate protecting collimator (for 1.5MHz):- Current baseline is still as per CM16/RAL:- D2 VSM1 CKV1 VSM2 HSM1 Q4-6 Q7-9 TOF0 TOF1 (some) Issues:- - Space provision. Collimator may sit on VSM1 ! - What design? - probably not one in place on day 1? Is it essential for TOF0/Ckv? * - how to use it : Insert & retune beamline? (best results-> 328 Good u -> 493) Downstream collimator (to reduce εn < ~ 3pi) :- Close to entrance to MICE (between Q9 & iron shield?) (some) Issues:- - This hasn’t been given serious consideration yet.

paul drumm, mutac jan Diffuser status (briefly) The MICE Analysis group are studying the radius of the diffuser. They conclude it should have radius > current 10cm, to study the larger emittance beams through MICE. A specification is being drawn up for input to WL. The actual thickness' of the diffusers' have not been specified - they come naturally from the optics work - but may need to be specified conservatively in advance?

paul drumm, mutac jan Beamline Commissioning / Diagnostics Commissioning ideas are being developed currently –Magnet testing –Basic startup: threading through the beamline –Setup as per A.Blondel / K.Long talk in Dec VC? –Further consideration being given to this by beamline group. Diagnostics:- –we are considering using our own beamline diagnostics to make the first setup of the beamline –ie. downstream of B1: scintillating glass? –fibre trackers (AB,PK,Fermilab) within the beamline –We will make good use of TOF0/1/Ckov1/Tracker when available. –We will need software to provide useful beam diagnostic output from the PIDs

paul drumm, mutac jan Work plans: It is clear that there are a long list of desirables:- all (ε,p) matrix cases (9? 12?..) steering scheme. tof0 collimation? d/stream collimation magnet testing/beamline commissioning plans etc and few people & little time, before Aug / Sept15. We (BL group) intend to draw up a work plan of what we can realistically achieve to be discussed with MICE. Prioritised work plan towards August/Sept