Transcript
Page 1: Update on ILC ML Lattice Design

Update on ILC ML Lattice Design

Alexander Valishev,for the FNAL LET group

FNAL

AP Dept. Meeting March 7, 2007

Page 2: Update on ILC ML Lattice Design

2APD meeting March 7, 07

ML Lattice design

Outline

• Basic layout• Curvature implementation• Matching• Summary and problems

Page 3: Update on ILC ML Lattice Design

3APD meeting March 7, 07

ML Lattice design

Lattice Design

• Defined by cryo segmentation• Versions of segmentation

» 8-8-8 scheme, Nov 21 2006» 9-8-9 scheme, Dec 28 2006

• Basic segmentations:

Main Linac

RF Unit

Cryogenic Unit

Page 4: Update on ILC ML Lattice Design

APD meeting March 7, 07

ML Lattice design

Nov. 21 revision (v.4) 8-8-8

Page 5: Update on ILC ML Lattice Design

5APD meeting March 7, 07

ML Lattice design

Lattice Revision HistoryDate Cav/

CMQ/CM Comments

1/06 12 1/2 USColdLC by PT, TESLA-like, straight

3/06 8 1/4 PT + curved

5/06 8 1/3 BCD-like, simple periodic lattice

5/06 8 1/3 Added cryo boxes and warm straights

6/06 8 1/3 May 31 (ver. 3) cryo layout

9/06 8 1/3 SBEND version *)

10/06 8 1/3 M.Woodley RTML-ML-BDS **)

1/07 8 1/3 “8-8-8” Nov 21. cryo layout (ver. 4)

2/07 9-8-9 1/3 “9-8-9” Dec 28. cryo layout

**) http://www.slac.stanford.edu/~mdw/ILC/2006e/

*) http://tdserver1.fnal.gov/project/ILC/ARCHIVE/ILC-ML-SbendCurvature.zip

Page 6: Update on ILC ML Lattice Design

6APD meeting March 7, 07

ML Lattice design

Curvature Implementation

• Beam line geometry definition differs for MatLIAR/Lucretia and MAD.

• A method to have one set of decks and still be able to work with two codes was proposed by M.Woodley:» One common XSIF file, defining beam line, all common

elements, and ‘KINK’ elements at the ends of cryomodules.

» Two different files defining KINK elements to be used in MatLIAR and MAD. One of the files is called from the main file depending on the software used.

» Beam trajectory in both cases is changed by VKICK elements

• Another approach is to use vertical SBENDs» In this case one deck is compatible with both codes

Page 7: Update on ILC ML Lattice Design

7APD meeting March 7, 07

ML Lattice design

Curvature Implementation

• GKICK, Multipole

• SBEND

Page 8: Update on ILC ML Lattice Design

8APD meeting March 7, 07

ML Lattice design

Implementation of ‘KINKs’

• MatLIAR/Lucretia: Thin ‘dispersion-free kick’ GKICK, which pitches the coordinate system.

• MAD: Combination of» General thin multipole n=0, changes both

the beam trajectory and the coordinate system

» VKICK of the opposite sign

Page 9: Update on ILC ML Lattice Design

9APD meeting March 7, 07

ML Lattice design

ILC2006e (8-8-8) Lattice -functions

MAD

LIAR

Lucretia

Page 10: Update on ILC ML Lattice Design

10APD meeting March 7, 07

ML Lattice design

ILC2006e Orbit

MAD Lucretia

Page 11: Update on ILC ML Lattice Design

11APD meeting March 7, 07

ML Lattice design

ILC2006e Dispersion

MAD Lucretia

Page 12: Update on ILC ML Lattice Design

12APD meeting March 7, 07

ML Lattice design

Emittance Preservation LIAR Simulation: CURVED LINAC: ILC BCD-Like LATTICE

Orb

it a

t th

e Y

CO

Rs

(m

)

Perfect Lattice - No misalignments

Zoom

No

rma

lize

d E

mit

tan

ce

(n

m)

Static Tuning: Dispersion Matched Steering (DMS) - Misalign the beamline components and perform the steering

Average of 50 machines

Straight

Curved

Co

rre

cte

d n

orm

ali

zed

em

itta

nc

e

(nm

)

Mean: 5.0 ± 0.4 nm

90%: 8.7 nm

Laser Straight

Mean: 5.3 ± 0.5 nm

90%: 9.5 nm

Curved

Distribution of emittance growth for 50 seeds

BPM index

BPM index

Page 13: Update on ILC ML Lattice Design

13APD meeting March 7, 07

ML Lattice design

Summary

• ML lattices based on two cryogenic layouts have been developed

• Two versions of ILC2006e (8-8-8) ML lattice (GKICK/MULT and SBEND) were studied» Both versions work well in Lucretia and show similar

emittance growth» It was decided at the Daresbury meeting in January

that only GKICK/MULT lattice will be supported

• Static alignment simulations show acceptable emittance growth in the curved ML lattice

• Dynamic simulations in progress

Page 14: Update on ILC ML Lattice Design

14APD meeting March 7, 07

ML Lattice design

TODO

• Create set of decks suitable for simulations of bunch propagation from RTML to the end

• Improve dispersion matching between curved and straight sections» The way it was implemented in ILC2006e suggests

large orbit kinks with angles of ~3e-4. At 250 GeV, this leads to energy losses of 100MeV and synchrotron radiation power of 4kW

» Angle of steering to the Earth’s curvature is 6e-6. Eloss=37keV, Ploss=1.6W

» One possible solution – make smooth transition from curved to straight beam line.

Page 15: Update on ILC ML Lattice Design

15APD meeting March 7, 07

ML Lattice design

Synchrotron Radiation in a Single Corrector

L

EB

3.0

L

EU SR

2441085.8

IavUP SRSR

E – particle energy [GeV]

– bending angle

L – corrector length [m]

B – corrector field [T]

USR – particle energy loss [eV]

Iav – average beam current [A]

PSR – average radiated power [W]

E=250L=0.335Iav=4e-5 for 1s beam at 5Hz

USR [keV] PSR [W]

5e-6 26 1.1

1e-5 100 4.5

5e-5 2600 110

1e-4 10300 450


Top Related