paul drumm, mutac jan 2003 1

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• 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 2003 2

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Since CM16 :

Nov / Dec:- Marginal time to progress. 2x meetings, 'some' work recommenced

- due ISIS pressures & no change in resource (KT)

Jan:- Returned @ ~ normal strength+ new Brunel postdoc (50%)+ (small%) IIT postdoc

but minus 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 2003 3

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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 2003 4

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Current (ε,p) Beamline Cases

• Current lattices are as per CM16:-

MeV

/c

(Two rows really here:For Fixed & ScaledTracker fields )

TT: Transport & TurtleG4: G4Beamline (incl new Ckv1)

p

1 6 10

240

200 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 2003 5

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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

1 6 10

240

200 TT

G4BL

TT

G4BL

TT

G4BL

140

paul drumm, mutac jan 2003 6

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- 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 2003 7

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- 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 √θ2

ttl ~ 0.7 √θ2g4bl

- 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

-25

-20

-15

-10

-5

0

5

10

15

20

25

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

TTL,x_rms

TTL,y_rms

G4BL,y_rms

G4BL,x_rms

Diffuser d/stream edgeTOF1

u/stream edge

Q9 d/stream MP edge

-25

-20

-15

-10

-5

0

5

10

15

20

25

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

TTL,x_rms

TTL,y_rms

G4BL,y_rms

G4BL,x_rms

Diffuser d/stream edgeTOF1

u/stream edge

Q9 d/stream MP edge

It's now clear why εg4bl >> εttl:

ε ~ Δx.Δx': -Δx.g4bl >> Δx.g4bl Δx':g4bl≈ Δx'.ttl

The cause for Δxg4bl maybe due to above (1,2) but should be found from studying the output differences?

paul drumm, mutac jan 2003 8

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- 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 2003 9

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Beam Steering/Correction Scheme

• Current baseline is still as per CM14/Osaka:-

Lattice dipoles and quads impede optimal placement. Best fit solution is:

B2 VS

M1

CK

V1

VS

M2

HS

M1

Q4-6 Q7-9TO

F0

TO

F1

(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 p0 @ 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 2003 10

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Collimation upstream & downstream

• TOF0 rate protecting collimator (for 1.5MHz):-Current baseline is still as per CM16/RAL:-

D2 VS

M1

CK

V1

VS

M2

HS

M1

Q4-6 Q7-9TO

F0

TO

F1

(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 2003 11

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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 2003 12

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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 2003 13

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• 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