nuSTORM RFFAG solution JB. Lagrange, J. Pasternak Imperial College, - - PowerPoint PPT Presentation

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nuSTORM RFFAG solution JB. Lagrange, J. Pasternak Imperial College, - - PowerPoint PPT Presentation

Oct 19, 2023 163 likes •454 views

nuSTORM RFFAG solution JB. Lagrange, J. Pasternak Imperial College, UK/Fermilab, USA 1 Outline Doublet solution Triplet solution Injection Improvements JB Lagrange - nuFACT 14 - August 2014 2 Outline Doublet solution Triplet

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SLIDE 1

nuSTORM RFFAG solution

  • JB. Lagrange, J. Pasternak

Imperial College, UK/Fermilab, USA

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SLIDE 2

JB Lagrange - nuFACT 14 - August 2014

Doublet solution Triplet solution Injection Improvements

Outline

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SLIDE 3

JB Lagrange - nuFACT 14 - August 2014

Doublet solution Triplet solution Injection Improvements

Outline

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JB Lagrange - nuFACT 14 - August 2014

Doublet solution

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Straight: 175 m, maximum scallop angle: 12 mrad

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JB Lagrange - nuFACT 14 - August 2014

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Cell parameters

Doublet solution

Circular Matching Straight Section Section Section Type FDF FDF Doublet Cell radius/length [m] 17.6 36.2 5 Opening angle [deg] 30 15 k-value/m-value 6.043 25.929 5.5 m−1 Packing factor 0.92 0.58 0.16 Maximum magnetic field [T] 2.5 3.3 1.5 horizontal excursion [m] 1.3 1.1 0.4 Full gap height [m] 0.45 0.45 0.45 Average dispersion /cell [m] 2.5 1.3 0.18 Number of cells /ring 4 × 2 4 × 2 35 × 2

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SLIDE 6

JB Lagrange - nuFACT 14 - August 2014

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Magnetic field for Pmax (+16%)

Doublet solution

  • 3.5
  • 3
  • 2.5
  • 2
  • 1.5
  • 1
  • 0.5

0.5 1 1.5 2 2.5 3 50 100 150 200 250 Bz [T] s [m]

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SLIDE 7

JB Lagrange - nuFACT 14 - August 2014

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Horizontal (plain red) and vertical (dotted purple) betafunctions for half of the ring.

Beta-functions at matching momentum

Doublet solution

5 10 15 20 25 30 35 40 50 100 150 200 250 [m] s [m]

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SLIDE 8

JB Lagrange - nuFACT 14 - August 2014

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Dispersion function at matching momentum

Doublet solution

0.5 1 1.5 2 2.5 50 100 150 200 250 [m] s [m]

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JB Lagrange - nuFACT 14 - August 2014

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Tune diagram ∆P

P = ±16%

Doublet solution

4 4.1 4.2 4.3 4.4 4.5 4.6 4.7 4.8 4.9 5 7 7.2 7.4 7.6 7.8 8

Qz Qx

4 4.1 4.2 4.3 4.4 4.5 4.6 4.7 4.8 4.9 5 7 7.2 7.4 7.6 7.8 8

Qz Qx

4 4.1 4.2 4.3 4.4 4.5 4.6 4.7 4.8 4.9 5 7 7.2 7.4 7.6 7.8 8

Qz Qx

4 4.1 4.2 4.3 4.4 4.5 4.6 4.7 4.8 4.9 5 7 7.2 7.4 7.6 7.8 8

Qz Qx

4 4.1 4.2 4.3 4.4 4.5 4.6 4.7 4.8 4.9 5 7 7.2 7.4 7.6 7.8 8

Qz Qx

4 4.1 4.2 4.3 4.4 4.5 4.6 4.7 4.8 4.9 5 7 7.2 7.4 7.6 7.8 8

Qz Qx

4 4.1 4.2 4.3 4.4 4.5 4.6 4.7 4.8 4.9 5 7 7.2 7.4 7.6 7.8 8

Qz Qx

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SLIDE 10

JB Lagrange - nuFACT 14 - August 2014

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Maximum horizontal stable amplitude over 100 turns Maximum vertical stable amplitude over 100 turns

Transverse acceptance

Doublet solution

  • 8
  • 6
  • 4
  • 2

2 4 6 8

  • 200
  • 100

100 200 x' [mrad] x [mm]

  • 8
  • 6
  • 4
  • 2

2 4 6 8

  • 200
  • 150
  • 100-50 0 50 100

150 200 z' [mrad] z [mm]

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SLIDE 11

JB Lagrange - nuFACT 14 - August 2014

Doublet solution Triplet solution Injection Improvements

Outline

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JB Lagrange - nuFACT 14 - August 2014

Motivations

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1300 km decay scenario incompatible with scallop of the closed orbit.

  • Doublet in the straight section cannot

be used. Triplet in the straight section.

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SLIDE 13

JB Lagrange - nuFACT 14 - August 2014

Triplet solution

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Straight: 180 m, maximum scallop angle: 24 mrad

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JB Lagrange - nuFACT 14 - August 2014

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Cell parameters

Triplet solution

Circular Matching Straight Section Section Section Type FDF FDF DFD Cell radius/length [m] 17.6 36.2 10 Opening angle [deg] 30 15 k-value/m-value 6.057 26. 5.5 m−1 Packing factor 0.92 0.58 0.24 Maximum magnetic field [T] 2.5 3.3 1.5 horizontal excursion [m] 1.3 1.1 0.6 Full gap height [m] 0.45 0.45 0.45 Average dispersion /cell [m] 2.5 1.3 0.18 Number of cells /ring 4 × 2 4 × 2 36 × 2

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SLIDE 15

JB Lagrange - nuFACT 14 - August 2014

15

Magnetic field for Pmax (+16%)

Triplet solution

  • 3.5
  • 3
  • 2.5
  • 2
  • 1.5
  • 1
  • 0.5

0.5 1 1.5 2 2.5 3 50 100 150 200 250 Bz [T] s [m]

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SLIDE 16

JB Lagrange - nuFACT 14 - August 2014

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Horizontal (plain red) and vertical (dotted purple) betafunctions for half of the ring.

Beta-functions at matching momentum

Triplet solution

5 10 15 20 25 30 35 40 50 100 150 200 250 [m] s [m]

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SLIDE 17

JB Lagrange - nuFACT 14 - August 2014

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Dispersion function at matching momentum

Triplet solution

0.5 1 1.5 2 2.5 50 100 150 200 250 [m] s [m]

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SLIDE 18

JB Lagrange - nuFACT 14 - August 2014

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Tune diagram ∆P

P = ±16%

Triplet solution

3 3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.8 3.9 4 6 6.2 6.4 6.6 6.8 7

Qz Qx

3 3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.8 3.9 4 6 6.2 6.4 6.6 6.8 7

Qz Qx

3 3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.8 3.9 4 6 6.2 6.4 6.6 6.8 7

Qz Qx

3 3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.8 3.9 4 6 6.2 6.4 6.6 6.8 7

Qz Qx

3 3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.8 3.9 4 6 6.2 6.4 6.6 6.8 7

Qz Qx

3 3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.8 3.9 4 6 6.2 6.4 6.6 6.8 7

Qz Qx

3 3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.8 3.9 4 6 6.2 6.4 6.6 6.8 7

Qz Qx

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SLIDE 19

JB Lagrange - nuFACT 14 - August 2014

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Maximum horizontal stable amplitude over 100 turns Maximum vertical stable amplitude over 100 turns

Transverse acceptance

Triplet solution

  • 10
  • 8
  • 6
  • 4
  • 2

2 4 6 8 10

  • 400 -300 -200 -100

100 200 x' [mrad] x [mm]

  • 8
  • 6
  • 4
  • 2

2 4 6 8

  • 200
  • 150
  • 100-50 0 50 100

150 200 z' [mrad] z [mm]

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SLIDE 20

JB Lagrange - nuFACT 14 - August 2014

Doublet solution Triplet solution Injection Improvements

Outline

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JB Lagrange - MAP meeting - May 14

(J. Pasternak)

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Preliminary Stochastic injection geometry

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JB Lagrange - MAP meeting - May 14

rad" Pions" Muons"

(J. Pasternak)

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Injection with matched dispersion

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JB Lagrange - MAP meeting - May 14

Septum(field(1.4(T((room(temperature)( Septum(thickness/length((~2cm/~72cm( It(requires(SC(dipole/septum(of(4(T(and(6(cm( thickness(to(be(placed(upstream((72(cm(in( length)( It(gives(20(cm(beam(clearance(at(the(upstream( FFAG(magnet.( Alternatively(we(could(use(~2cm/164(cm(SC( septum(with(1.8T((results(are(pretty(the(same)( (

(J. Pasternak)

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Injection parameters with matched dispersion

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JB Lagrange - MAP meeting - May 14

Zoom$in$

rad$ Pions$

(J. Pasternak)

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JB Lagrange - MAP meeting - May 14

(note)the)inverse)direction))

rad) Pions) Muons)

(J. Pasternak)

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Injection with no dispersion (reversed direction)

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JB Lagrange - MAP meeting - May 14

Septum(field(0.8(T((room(temperature)( Septum(thickness/length((~2cm/~164cm( It(gives(20(cm(beam(clearance(at(the(upstream( FFAG(magnet.( The(pion(orbits(will(oscillate(in(the(decay( section.(We(need(to(evaluate,(how(this(affects( the(muon(collection(efficiency.( (

(J. Pasternak)

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Injection parameters with no dispersion

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JB Lagrange - nuFACT 14 - August 2014

Doublet solution Triplet solution Injection Improvements

Outline

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JB Lagrange - nuFACT 14 - August 2014

Future improvements

Small scallop angle in the straight: reduce the portion

  • f the straight cell with scallop.

Larger DA: smaller gradient (m-value) in the straight section Smaller magnets in the arcs: reduce the maximum dispersion in the arcs (> 1.3 m necessary for injection). Neutrino flux estimation from pion & muon decay for doublet and triplet lattice, and comparison with FODO (see D. Adey’s talk).

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JB Lagrange - nuFACT 14 - August 2014

Thank you for your attention

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