Alex Bogacz Vasiliy Morozov, Yves Roblin, Jefferson Lab Kevin Beard, Muons Inc

Operated by JSA for the U.S. Department of Energy

Thomas Jefferson National Accelerator Facility

Alex Bogacz

1

Muons, Inc.Alex Bogacz

Alex Bogacz

Vasiliy Morozov, Yves Roblin, Jefferson Lab

Kevin Beard, Muons Inc.

Muon RLA Design Status and New Options

MAP Winter Meeting, Jefferson Lab, March 2, 2011



Alex Bogacz

2


Linac and RLAs IDS

244 MeV

0.6 GeV/pass3.6 GeV

0.9 GeV

146 m

79 m

2 GeV/pass

264 m

12.6 GeV


79 m

RLA with FFAG Arcs

IDS Goals:

Define beamlines/lattices for all components

Matrix based end-to-end simulation (machine acceptance) (OptiM)

Field map based end-to-end simulation: ELEGANT, GPT and G4Beamline

Error sensitivity analysis

Component count and costing

Two regular droplet arcs replaced by one two-pass FFAG arc

K. Beard

Y. Roblin

C. Bontoui

Vasiliy Morozov



Alex Bogacz

3


30-30 S [cm] View at the lattice beginning

15

0-1

50

dP

/P *

10

00

,

Pre-Linac - Longitudinal phase-space


ELEGANT (Fieldmap)

OptiM (Matrix)

Initial distribution

x/y = 4.8 mm radlp z/mc = 24 mm



Alex Bogacz

4


Injection/Extraction Chicane

1.5 GeV

$Lc = 60 cm$angH = 9 deg.$BH = 10.2 kGauss

2.1 GeV

$Lc = 60 cm$angV = 5 deg.$BV = 4.7 kGauss

H -H V H-H-V3 cells

4 cells

300

300

1-1

BE

TA

_X&

Y[m

]

DIS

P_X

&Y

[m]

BETA_X BETA_Y DISP_X DISP_Y

FODO lattice:

900/1200 (h/v) betatron phase adv. per cell

Double achromat Optics

0.9 GeV

50 cm

1.7 m




Alex Bogacz

5


Chicane - Double Achromat Optics

300

300

1-1

BE

TA

_X&

Y[m

]

DIS

P_X

&Y

[m]


300

0.

50

PH

AS

E_X

&Y

Q_X Q_Y

x

y

FODO quads:

L[cm] = 50

F: G[kG/cm] = 0.322

D: G[kG/cm] = -0.364

betatron phase

H -H V H-H-V3 cells

4 cells

sextupole pair to correct vert. emittance dilution

Double achromat Optics




Alex Bogacz

6


78.91030

150

50

BE

TA

_X&

Y[m

]

DIS

P_X

&Y

[m]


39.91030

150

50

BE

TA

_X&

Y[m

]

DIS

P_X

&Y

[m]


Multi-pass Linac Optics – Bisected Linac

1-pass, 1200-1800 MeV

‘half pass’ , 900-1200 MeV initial phase adv/cell 90 deg. scaling quads with energy

mirror symmetric quads in the linac

quad gradient

quad gradient




Alex Bogacz

7


Multi-pass bi-sected linac Optics


389.3020

300

50

BE

TA

_X&

Y[m

]

DIS

P_X

&Y

[m]


1.2 GeV0.9 GeV 3.0 GeV2.4 GeV1.8 GeV 3.6 GeV

Arc 4Arc 3Arc 2Arc 1

x = 3.2 m y = 6.0 mx =-1.1 y =1.5 x,y → x,y

xy → xy

x,y → x,y

xy → xy

x,y → x,y

xy → xy

x,y → x,y

xy → xy

x = 6.3 m y = 7.9 mx =-1.2 y =1.3

x = 7.9 m y = 8.7 mx =-0.8 y =1.3

x = 13.0 m y = 14.4 mx =-1.2 y =1.5

quad grad.

length



Alex Bogacz

8


Linac-to-Arc – Chromatic Compensation

E =1.8 GeV

‘Matching quads’ are invoked

No 900 phase adv/cell maintained across the ‘junction’

Chromatic corrections needed – two pairs of sextupoles

36.91030

15

0

3-3

BE

TA

_X&

Y[m

]

DIS

P_

X&

Y[m

]

BETA_X BETA_Y DISP_X DISP_Y 720

15

0

3-3

BE

TA

_X&

Y[m

]

DIS

P_

X&

Y[m

]





Alex Bogacz

9


Linac-to-Arc Chromatic Corrections

30-30 X [cm] View at the lattice beginning

80

-80

X`[

mra

d]

30-30 X [cm] View at the lattice end

80

-80

X`[

mra

d]

30-30 X [cm] View at the lattice end

80

-80

X`[

mra

d]

initial uncorrected two families of sextupoles

36.91030

15

0

3-3

BE

TA

_X&

Y[m

]

DIS

P_

X&

Y[m

]

BETA_X BETA_Y DISP_X DISP_Y 720

15

0

3-3

BE

TA

_X&

Y[m

]

DIS

P_

X&

Y[m

]





Alex Bogacz

10


10 cells in2 cells out

2 cells out

footprint

-5000

-4000

-3000

-2000

-1000

0

1000

2000

3000

4000

5000

0 2000 4000 6000 8000 10000

z [cm]

x [cm]

(out = in and out = -in , matched to the linacs)

transition

transition

E =1.2 GeV

40-40 S [cm] View at the lattice end

30

0-3

00

dP

/P *

10

00

,


300

-300

dP/P

* 1

000,

Mirror-symmetric ‘Droplet’ Arc – Optics

1300

150

3-3

BE

TA

_X&

Y[m

]

DIS

P_X

&Y

[m]





Alex Bogacz

11


Alternative multi-pass linac Optics


389.3020

900

50

BE

TA

_X&

Y[m

]

DIS

P_X

&Y

[m]


1.2 GeV0.9 GeV 3.0 GeV2.4 GeV1.8 GeV 3.6 GeV

Arc 1 Arc 4Arc 3Arc 2Arc 1

x = 3.2 m y = 6.0 mx =-1.1 y =1.5

Arc 2x = 3.2 m y = 6.0 mx =-1.1 y =1.5

Arc 3x = 3.2 m y = 6.0 mx =-1.1 y =1.5

Arc 4x = 3.2 m y = 6.0 mx =-1.1 y =1.5

x,y → x,y

xy → xy

x,y → x,y

xy → xy

x,y → x,y

xy → xy

x,y → x,y

xy → xy

quad grad.

length



Alex Bogacz

12


Arcs ‘Crossing’ - Vertical Bypass

420

300

2-2

BE

TA

_X&

Y[m

]

DIS

P_X

&Y

[m]


4 vertical bends:B = 1 TeslaL = 10 cm

E = 1.2. GeV

y = 25 cm


V

-V

V

-V4 cells (900 FODO)

Dogbone RLA - footprint

-5000

-4000

-3000

-2000

-1000

0

1000

2000

3000

4000

5000

6000 11000 16000 21000 26000 31000

z [cm]

x [cm]



Alex Bogacz

13


‘Droplet’ Arcs scaling – RLA I

i = 1…4

Ei

[GeV]

pi/p1 cell_out

cell_in

length [m]

Arc1Arc1 1.2 1 2×2 10 130

Arc2Arc2 1.8 1.43 2×3 15 172

Arc3Arc3 2.4 1.87 2×4 20 214

Arc4Arc4 3.0 2.30 2×5 25 256

Fixed dipole field: Bi =10.5 kGauss

Quadrupole strength scaled with momentum: Gi = × 0.4 kGauss/cm

Arc circumference increases by: (1+1+5) × 6 m = 42 m

footprint

-5000

-4000

-3000

-2000

-1000

0

1000

2000

3000

4000

5000

0 2000 4000 6000 8000 10000

z [cm]

x [cm]

1p

pi




Alex Bogacz

14


‘Droplet’ Arcs scaling – RLA II

i = 1…4

Ei

[GeV]

pi/p1 cell_out

cell_in

length [m]

Arc1Arc1 4.6 1 2×2 10 260

Arc2Arc2 6.6 1.435 2×3 15 344

Arc3Arc3 8.6 1.870 2×4 20 428

Arc4Arc4 10.6 2.305 2×5 25 512

Fixed dipole field: Bi = 40.3 kGauss

Quadrupole strength scaled with momentum: Gi = × 1.5 kGauss/cm

Arc circumference increases by: (1+1+5) × 12 m = 84 m

footprint

-5000

-4000

-3000

-2000

-1000

0

1000

2000

3000

4000

5000

0 2000 4000 6000 8000 10000

z [cm]

x [cm]

1p

pi




Alex Bogacz

15


Component Count

beamline RF cavities solenoids

dipoles quads sext

1-cell 2-cell

pre-accelerator 6 62 25

inj-chic I 8+3 16 3

RLA I

linac 24 26

arc1 35 43

arc2 49 57 8

arc3 63 71 8

arc4 77 85 8

inj-chic II 8+3 16 3

RLA II

linac 80 42

arc1 35 43

arc2 49 57 8

arc3 63 71 8

arc4 77 85 8

Lambertson 1




Alex Bogacz

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Summary


Piece-wise end-to-end simulation with OptiM/ELEGANT (transport codes)

Solenoid linac

Injection chicane I (new more compact design)

RLA I + Injection chicane II + RLA II

Chromaticity correction with sextupoles validated via tracking

Alternative multi-pass linac optics

Currently under study… GPT/G4beamline

End-to-end simulation with fringe fields (sol. & rf cav.)

Engineer individual active elements (magnets and RF cryo modules)



Alex Bogacz

17


Backup slides




Alex Bogacz

18


Linac-RLA Acceptance Initial phase-space after the cooling channel at 220

MeV/c ISS/IDS rms

A = (2.5)2

normalized emittance: x/y mmrad 4.8 30

longitudinal emittance: l

lp z/mc)

momentum spread: p/p

bunch length: z

mm

mm

24

0.07

165

150

0.17

412

x,y = 2.74 m

x,y = -0.356

= 2.08

20-20 X [cm] View at the lattice beginning

80

-80

X`[

mra

d]


18

0-1

80

dP

/P *

10

00

,


Documents

Alex Bogacz Vasiliy Morozov, Yves Roblin, Jefferson Lab Kevin Beard, Muons Inc