Design Concept

1
Design Concept New Baseline Description.

• Brief Review of Design Concept
• Beam Matching Emittance Provision
• Design Concept
• New Baseline Description
• Pre-amble Abingdon JAN04
• Inputs for Revising Layout
• Design of Present Layout Results.
• Summary

• Kevin Tilley , ISIS , RAL

2
Design Concept
(1) Matching (2) Emittance Provision and
the solution to obtain both taken here.
3
Design Concept Lite

1. Matching..

the MICE beam profile assumes a parallel,
constant beam radius in the Spectrometer Solenoid
Tracker.
it is important the beamline furnishes such a
beam profile, such that useful beam rate is high
, MICE can be tuned as designed etc. eg. Beta
42cm etc. _at_ Abs .
4
Design Concept Lite
How do we ensure this?
In Beam Optics language,
Matching into a solenoid
For illustration
Consider particle trajectories
If we therefore inject a BEAM DISTRIBUTION with
this rr elliptical shape..
hence,
jump to cartesian hence we have our beam cdns
for MATCHING -
. unchanged rmax stays constant !
x
ditto for y
x
5
Design Concept Lite
(2) Emittance Provision
MICE also wants a controlled, scalable
emittance into the experiment
Using Lapostelles RMS-
6
Design Concept Lite
So MICE wants
. at matching point (4T Spec Solenoid)
7
Design Concept Lite
Scheme to provide simulateously-
This is the driving Design Concept in this design
work To use Beamsize Scatterer thickness
to provide both beam matching, required
emittance generation.
Above figure illustrates case match region
immediately follows scatterer
8
Preamble- Status Abingdon CM
50cm Y 0cm X 50cm
Pion Injection Decay Solenoid. (PION Profile)

Muon Extraction (MUON Profile)
50cm Y 0cm X 50cm
Scheme to generate and
simultaneously match into MICE.
Collection of Major suggestions made at and
shortly after the Abingdon collaboration meeting
.

• Make certain design changes to become more
  realistic for MICE-

• Pion injection decay section-
• Muon extraction-

• Aim for focussed pion beam at B2 (to aid
  pion/muon purity)
• Design using only 6 x Q35s, placed after dipole
  B2.
• Design for Muon momentum of Pu 240Mev/c.
• Make allowance for TOF PID needs after B2.
• Design for suitability at

• Distribute above design and work to obtain some
  convergence between codes.

9
Preamble- Status Jan 04
50cm Y 0cm X 50cm
Pion Injection Decay Solenoid. (PION Profile)

Muon Extraction (MUON Profile)
50cm Y 0cm X 50cm
Scheme to generate and
simultaneously match into MICE.
Compiled then even bigger list of inputs in order
to inform the re-baselining ..
10
Inputs for Revised Layout
Collection of the Major inputs compiled after
January 04 .

• Incorporate further changes to become more
  realistic for MICE-

• Focusing and matching with Q35 Quads affirmed
  not coils.
• Not designing achromatic muon extraction (maybe
  some residual dispersion)
• Extend B1 Decay Sol distance to fit wall-hole
  geometry (hole 650mm)
• Muon purity as high as possible (C2H4 absorber,
  pion focus at B2?)
• TOF0 TOF1 Q4/Q5, Q8/Q9. Min Sepn 6.9m JAN04.
  TOF length 15cm.
• Q9 Saturation Q9 Start / End Coil 1.1
  distance no closer than JAN04 (Q9 0.08T)
• ? End / Q9MP St/EC 1.1 1.2169m
• Minimum Physical Pb. to Start / EC 1.1 distance
• EC-VacCh 0.195 TrServ
  0.03 UpStrDtrSh 0.15 Space ? Take 0.390m.
• (here it is thus after
  Cherenkov before any Upstream Detector
  Shielding)
• Max Additional total lengthwise movement of
  beamline/MICE 2.00m
• Initial Muon Momentum Pu 260Mev/c, for
  236.5Mev/c after Pb (aiming at ctr A.v.p for
  pref200)
• Design for suitability at
• Spectrometer End Coils NOT available for beam
  matching.
• Quadrupole / Dipole FFs neglected. Use magnet
  effective lengths.

11
Present design (PiDecay Sectn)
50cm Y 0cm X 50cm
0m (TGT)
7.434m 9.665m
15.282m
12
Muon Extn Design
Difficulties with finite Pb, - End Coil
Seperation
- First assessment of revising matching
conditions before scatterer, based on free field
region Pb ? EC. start. Clearly approximation, and
maybe pessimistic?

• Finite distance to matching region (EndCoils
  here) means incoming beam must be heavily
  converging into scatterer in order that still
  converging to matched focus at EC.

13
Muon Extn Design ctd
Using every available option to get large
..!

• d 0.240m (Upstream of Tracker Servs only)
• Q9 Pb distance ? 0.0m ? Removed CKOV1
  Upstream Sh to Elsewhere
• Removed all Quad MPs (to minimise spacings)

- Conclusion of this modelling indicated better
to reduce d? 0.0m ! Initial discussion RAL/IC
indicated maybe possible to engineer Pb within
re-entrant VacCh close to ECs thus ? present
purpose took d0.0m
14
Present design (Muon Extraction)
50cm Y 0cm X 50cm

• RMS Beam Profile
• Shows p0 260Mev/c
• Collimation in x.

15.282m 17.735m 20.827m
24.977 m 28.069m
29.478m (Pb).
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Details Engineering dwg.
Half-Apertures (cm) Half-Apertures (cm) Half-Apertures (cm)
zC-dist St.Leff Element Pole Tips (Quads) Vertical Horizontal Strength

0.0 Drift Space 10 10
2.573 Type 4 NIM Qd -Q1 10.15 10.15 10.15 0.919537 T m-1 0.919537 T m-1
3.427 Drift Space 10 10
3.973 Type 4 NIM Qd -Q2 10.15 10.15 10.15 -1.14943T m-1 -1.14943T m-1
4.827 Drift Space 10 10
5.373 Type 4 NIM Qd -Q3 10.15 10.15 10.15 0.827586T m-1 0.827586T m-1
6.227 Drift Space 10 10
7.434 Type 1 NIM Dipole - B1 (sym otd) Type 1 NIM Dipole - B1 (sym otd) 10 33 1.124721 T
8.521 Drift Space 10 10
9.665 Decay Solenoid 6 6 4.7 T
14.665 Drift Space 10 10
15.282 Type 1 NIM Dipole - B2 (sym otd) Type 1 NIM Dipole - B2 (sym otd) 10 33 0.43249 T
16.336 Drift Space
17.735 Q35 Qd - Q4 17.82 23.6 23.6 1.642054 T m-1
18.395 Drift Space
18.951 Q35 Qd -Q5 17.82 23.6 23.6 -1.70263 T m-1
19.611 Drift Space
20.167 Q35 Qd - Q6 17.82 23.6 23.6 1.813361 T m-1
20.827 Drift Space
24.977 Q35 Qd - Q7 17.82 23.6 23.6 1.693973 T m-1
25.637 Drift Space
26.193 Q35 Qd - Q8 17.82 23.6 23.6 -1.51313 T m-1
26.853 Drift Space
27.409 Q35 Qd - Q9 17.82 23.6 23.6 1.254287 T m-1
28.069 Final Drift Space.

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Assessment with TTL
Before the Scatterer
- Tuned for 260Mev/c
- But p-peak 281Mev/c !
- Not totally new news (JAN04)but
annoying/(wasteful?).
Ideas, but cause still not fully understood.
And on closer examination.
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Assessment with TTL
Before the Scatterer
/-1 260Mev/c.
.GOOD BEAM
Clearly Splits into 2 distinct components.
/1 Higher p 281Mev/c.
.BAD BEAM
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Assessment with TTL
Thus worked only with the 260Mev/c good beam
component.
Before Scatterer
/-1 260Mev/c.
Found needed2.64cm Pb to achievesufficient
for
Momentum drop quite steep, thus stopped at the
above
Scatterer
/-1 212Mev/c.Match for
After Scatterer
19
Assessment with TTL
NET. after the Scatterer, and Going into the
Experiment
WELL MATCHED BEAM _at_ 212Mev/c
/-1 212Mev/c.
/-1 Higher p 237Mev/c.
PARTIALLY MATCHED? CMPT _at_ 237Mev/c
ltpgt237Mev/c, ?p/p11.6
20
Assessment with TTL
First Estimate of where this might cover on the
A.v.p momentum correlation chart?-
265Mev/c
ltpgt 237Mev/c
212Mev/c
209Mev/c
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Summary

• Design Concept described.
• Motivations behind present baseline layout
  given.
• New Baseline described.
• Current beamline provides ltpgt237Mev/c,
  ?p/p11.6
• Well matched component at 212Mev/c _at_
• Partially matched dominating higher momentum
  component.
• Intention to revise for well matched _at_
  236.5Mev/c.
• Current modelling forced Pb-EC ? 0 based on
  scheme.
• Clearly one priority to consider same finite d
  cases including MICE (EC/SS) FFs
• Incorporates most of other inputs.