Alex Bogacz, 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

Alex Bogacz, Yves Roblin, Jefferson Lab

Kevin Beard, Muons Inc.

Morteza Aslaninejad, Cristian Bontoiu, Jürgen Pozimski Imperial College

Vasiliy Morozov, Old Dominion University

Status of Linac and RLAs –

Simulations

IDS-NF 5-th Plenary Mtg. Fermilab, April 9, 2010



Alex Bogacz 2

Linac and RLAs – ‘Big picture’

0.6 GeV/pass3.6 GeV

0.9 GeV244 MeV

146 m

79 m

2 GeV/pass

264 m

12.6 GeV

IDS Goals:

Define beamlines/lattices for all components

Resolve physical interferences, beamline crossings etc

Error sensitivity analysis

End-to-end simulation (machine acceptance)

Component count and costing


1st part of this talk

2nd part of this talk



Alex Bogacz 3

RLA Lattice Studies Status

Presently completed lattices

Linear pre-accelerator – solenoid focusing

4.5 pass Dogbone RLA × 2 (RLA I + RLA II)

Optimized multi-pass linac optics (bisected - quad profile along the linac)

Droplet return arcs (4) matched to the linacs

Transfer lines between the components – injection chicanes

Droplet arcs crossing – Double achromat Optics design

Chromatic corrections with sextupoles at Spr/Rec junctions

Error analysis for the Arc lattices (proof-or-principle)

Magnet misalignment tolerance – DIMAD Monte Carlo Simulation

Focusing errors tolerance – betatron mismatch sensitivity

Piece-wise end-to-end simulation with OptiM (pre-accelerator + RLA I)




Alex Bogacz 4

Muon Acceleration Mini-workshop

http://casa.jlab.org/external/2010/MuonAcceleration_MiniWorkshop/


Feb 2-5, 2010



Alex Bogacz 5

Solenoid Linac (244 -909 MeV)


6 short cryos

15 MV/m

8 medium cryos

17 MV/m

11 long cryos

17 MV/m

1.1 Tesla solenoid 1.4 Tesla solenoid 2.4 Tesla solenoid

Transverse acceptance (normalized): (2.5)2= 30 mm rad

Longitudinal acceptance: (2.5)2 pz/mc= 150 mm

1460

Sat Dec 13 22:36:02 2008 OptiM - MAIN: - D:\IDS\PreLinac\Sol\Linac_sol.opt

120

50

BE

TA

_X&

Y[m

]

DIS

P_X

&Y

[m]

BETA_X BETA_Y DISP_X DISP_Y



Alex Bogacz 6

Linac – tracking studies


DONE SO FAR:

shielded two-shell solenoid modeled with POISSON

RF cavities modeled with SUPERFISH, COMSOL, & CST

front-to-end lattice for OptiM (solenoids, dipoles, quadrupoles, & sextupoles)

linac lattice tested in MAD-X

beam tracking using GPT

optical match of linac to cooling channel with one solenoid

beam-loading effects evaluated as negligible

standard for exchanging data files proposed



Alex Bogacz 7

Solenoid Model (Superfish)


outer coil

inner coil

shield

2e

pc

22 2

edge z 0

-

1 k a= B (s) ds B L

2 8

e

pc 0k = B

‘Soft-edge’ Solenoid

21Ls

a

z 0

1B (s) = B tanh

2



Alex Bogacz 8

Two-cell cavity (201 MHz) – COMSOL

Morteza Aslaninejad

Cristian Bontoiu

Jürgen Pozimski




Alex Bogacz 9

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]

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

18

0-1

80

dP

/P *

10

00

,




Alex Bogacz 10NFMCC Collaboration Meeting, Oxford, MS, January 14, 2010

Transverse acceptance (normalized): (2.5)2= 30 mm rad

Longitudinal acceptance: (2.5)2 pz/mc= 150 mm

Linac Optics – Beam envelopes

1460

Thu Apr 08 13:54:52 2010 OptiM - MAIN: - C:\Working\IDS\PreLinac\Linac_sol.opt

300

300

Siz

e_X

[cm

]

Siz

e_Y

[cm

]

Ax_bet Ay_bet Ax_disp Ay_disp



Alex Bogacz 11

Linac Optics – OptiM vs ELEGANT

a = 19.5 cm

a = 19.5 cm

Yves Roblin


1460

Sat Dec 13 22:36:02 2008 OptiM - MAIN: - D:\IDS\PreLinac\Sol\Linac_sol.opt

120

50

BE

TA

_X&

Y[m

]

DIS

P_X

&Y

[m]




Alex Bogacz 12

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

15

0-1

50

dP

/P *

10

00

,


15

0-1

50

dP

/P *

10

00

,Longitudinal phase-space

tracking

Initial distribution

OptiM

ELEGANT


Yves Roblin

Alex Bogacz

MATHCAD

MATLAB

Morteza Aslaninejad

Kevin Beard



Alex Bogacz 13

Cooling Channel – Linac Optics


B||



Alex Bogacz 14

GPT Particle Tracking in the Linac


upper middle linaccooling upper linac



Alex Bogacz 15

Include cavity filling effect on accelaration

Get a more accurate initial distribution

Design an improved cooling-to-linac section

Upgrade analytic cavity phasing – check against GPT

Complete linac lattice via tuning solenoids, phasing

cavities, & tracking with GPT

Linac and RLAs - ‘field map’ tracking


TO DO NEXT:



Alex Bogacz 16

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

Wed Jun 11 13:14:37 2008 OptiM - MAIN: - D:\IDS\Linacs_short\Linac1_fudg.opt

15

0

3-3

BE

TA

_X&

Y[m

]

DIS

P_

X&

Y[m

]

BETA_X BETA_Y DISP_X DISP_Y 720

Wed Jun 11 14:08:34 2008 OptiM - MAIN: - D:\IDS\Arcs\Arc2_match.opt

15

0

3-3

BE

TA

_X&

Y[m

]

DIS

P_

X&

Y[m

]




Alex Bogacz 17

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

Wed Jun 11 13:14:37 2008 OptiM - MAIN: - D:\IDS\Linacs_short\Linac1_fudg.opt

15

0

3-3

BE

TA

_X

&Y

[m]

DIS

P_

X&

Y[m

]

BETA_X BETA_Y DISP_X DISP_Y 720

Wed Jun 11 14:08:34 2008 OptiM - MAIN: - D:\IDS\Arcs\Arc2_match.opt

15

0

3-3

BE

TA

_X

&Y

[m]

DIS

P_

X&

Y[m

]




Alex Bogacz 18

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

Tue Jun 10 21:14:41 2008 OptiM - MAIN: - D:\IDS\Arcs\Arc1.opt

150

3-3

BE

TA

_X&

Y[m

]

DIS

P_X

&Y

[m]




Alex Bogacz 19

Multi-pass FFAG Arc


2 or more passes through the same arc e.g. 5 GeV and 9 GeV

NS-FFAG arc lattice design

Achromatic basic cell with 90 horizontal phase advance

Automatic matching between inward and outward bending cells

Linear optics understood

Need to incorporate sextupole and higher-order field components to accommodate higher momenta

Basic cell

example trajectories

dispersion

COSY Infinity

Vasiliy Morozov



Alex Bogacz 20IDS-NF 5-th Plenary Mtg. Fermilab, April 9, 2010

60

300

simple closing of geometrywhen using similar cells

Multi-pass FFAG Arc

r = 38.5 meters

C = 302 meters

Vasiliy Morozov



Alex Bogacz 21

Proposed SDDS Exchange Format


•ZGOUBI•ELEGANT•G4beamline•ICOOL•OptiM•COSY-Infinity•MAD-X•GPT•…

http://casa.jlab.org/external/2010/MuonAcceleration_MiniWorkshop/SDDS/draft.html

Kevin Beard



Alex Bogacz 22

Summary


Critical components of front-end linac modeled

Initial design of the front-end linac simulated

Design matching sections simulated

RLA arc lattice + chromaticity compensation simulated

Putting the pieces together for end-to-end simulations

Multi-pass (2) FFAG Arcs?

Alex Bogacz, Yves Roblin, Jefferson Lab Kevin Beard, Muons Inc.

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