ACCELERATOR DESIGN OF THE NSLS-II SYNCHROTRON LIGHT SOURCE

1 BROOKHAVEN SCIENCE ASSOCIATES

ACCELERATOR DESIGN OF THE NSLS-II SYNCHROTRON LIGHT SOURCEACCELERATOR DESIGN OF THE NSLS-II SYNCHROTRON LIGHT SOURCE

W. T. Weng CENTER OF ACCELERATOR PHYSICS, BNL

Forum on Low Emittance Intermediate Energy Synchrotron Light Source

August 19-20, 2004 NSRRC, Shin-Chu, Taiwan


ACKNOWLEDGMENTACKNOWLEDGMENT

The material presented here are provided by scientists at NSLS, especially

Drs. S. Dierker C. C. Kao J. Murphy S. Kramer Zhong Zhong


Present NSLSPresent NSLS

VUV/IR Ring800 MeV1000 mA

X-Ray Ring2.8 GeV275 mA

80OperationalBeamlines


Diverse Science:Users by Field of Research

Diverse Science:Users by Field of Research

OtherApplied Science and Engineering

Geological and

Environ.Sciences

Life Sciences

Chemical Sciences

Material Sciences

• Largest groups are materials and life sciences

• Strongest growth in life sciences


National & Regional ResourceNational & Regional Resource

InternationalInternational

New YorkNew York

Other Other Northeast StatesNortheast States

Non-Northeast Non-Northeast StatesStates

(32%)

Industry: IBM, ExxonMobil, Lucent, pharmaceuticals

Central to BNL programs

(27%)

(25%)

(16%)

2400 Users/year2400 Users/year (> 400 academic, industrial, government institutions)


NSLS -- INSLS -- I

• First Dedicated Second Generation Synchrotronand only remaining second generation DOE synchrotron!

• Designed in the 1970’s • Operating Since 1982• Continually updated over the years

- Brightness has improved more than 100,000 fold• However, we are at the theoretical limit with existing ring• Restricted capabilities of present NSLS are increasingly

limiting the productivity and impact of its large user community• Major improvements require replacing ring


10+ Year Vision:10+ Year Vision:

What science will users do in 10+ years, and what do they need ?• Soft Matter & Biomaterials Workshop – April ‘02• 8 Workshops at NSLS Users Meeting – May ‘02• Ultra-high Resolution X-ray Spectroscopy Workshop – September ‘02• Low Energy Electrodynamics in Solids Conference – October ‘02• Microbeam Diffraction Workshop – January ‘03• 6 Workshops at NSLS Users Meeting– May ‘03• Scientific Opportunities in Macromolecular Crystallography at NSLS-II – July ‘ 03• NSLS-II Environmental Science – August ‘03• Strongly Correlated Electrons: NSLS-II and the Future – August ‘03• Scientific Opportunities in Soft Matter and Biophysics at NSLS-II – Sept. ‘03• Biomedical Imaging at NSLS-II – September ‘ 03• Nanoscience and NSLS-II – October ‘03• Workshop for NSLS-II – March ‘04• CD0 Review Feedback, August ‘04

Enable Grand Challenge Science by Providing World Leading CapabilitiesEnable Grand Challenge Science by

Providing World Leading Capabilities


MAJOR DESIGN CONSIDERATIONSMAJOR DESIGN CONSIDERATIONS

• Science Case and User’s Needs, National & International Competition, ( to be covered by C. C. Kao )• Facility Type: FEL, ERL, SR, SR-ERL• Injector: Linac vs Booster, Top-Up• Lattice: Energy, Emittance, DBA vs TBA, SS• RF: Warm vs Cold, Frequency, Bunch Length, Voltage• Insertion: Superconducting vs PM Undulator, Photon E• Upgrade Path and Growth Potential• R&D Program, Critical Technology • Cost and Construction Schedule


NSLS-II: Ultra-high Brightness Medium EnergyThird Generation X-Ray Ring and IR Ring

NSLS-II: Ultra-high Brightness Medium EnergyThird Generation X-Ray Ring and IR Ring

X-ray Ring• 3 GeV, 500 mA, Top-off Injection• 24 Cell, Triple Bend Achromat• Circumference 620 m• 21 Insertion Device Straight Sections (7 m)• 24 Bending Magnet Ports• Ultra-Low Emittance (x, y) 1.5, 0.008

nm(Diffraction limited in vertical at 10 keV)

• Brightness ~ 1021 p/s/0.1%bw/mm2/mrad2

• Flux ~ 1016 p/s/0.1%bw• Beam Size (x, y) 84.6, 4.3 m• Beam Divergence (x’, y’) 18.2, 1.8

rad• Pulse Length (rms) 11 psec• Exceptional intensity and position stability• Upgradeable to ERL operation in future

Infrared Ring• 800 MeV, 1000 mA, Top-off Injection

Highly Optimized X-ray Storage Ring

Dedicated Enhanced Infrared Ring


Parameters Of Some IE/LE Synchrotron Light SourcesParameters Of Some IE/LE Synchrotron Light Sources

Name Ee(Mev)

Length(m)

Emittance(nm-rad)

Straight Sect.(No. x m)

Current(mA)

SOLEIL 2.75 354.1 3.73 12 x 7, 8 x 3.6 4 x 12

500

SLS 2.4 288 5.0 6 x 4, 3 x 73 x 11

400

DIAMOND 3.0 561.6 2.7 6 x 9.418 x 5.9

300

SSRF 3.5 432 3.0 4 x 1216 x 6.4

300

NSLS-II 3.0 620 1.5 24 x 4.0 500


Summary of Proposed NSLS-II Lattices Summary of Proposed NSLS-II Lattices L a t t i c e T y p e D B A ( n A ) T B AC i r c u m f e r e n c e , C [ m ] 6 3 0 6 2 0 . 4S u p e r p e r i o d s , N s 2 8 2 4S t r a i g h t S e c t i o n L e n g t h , L s s [ m ] 7 7H o r i z o n t a l E m i t t a n c e , [ n m ] 2 . 1 4 ( 1 . 0 4 ) 1 . 5 4M o m e n t u m C o m p a c t i o n , 41 . 7 1 ( 0 . 7 9 ) 1 0 58 . 1 5 ( 1 4 . 5 ) 1 0 D i p o l e R a d i u s , 8 . 0 2 7 . 6 4F i e l d I n d e x , n 3 6 2 1 . 5B e t a t r o n T u n e s

x , y 3 6 . 3 7 , 1 9 . 2 7

( 3 6 . 3 7 , 1 9 . 7 7 )3 7 . 3 , 1 7 . 2 5

U n c o r r e c t e d C h r o m a t i c i t y , x y, - 9 8 . 0 5 , - 2 8 . 6 2( - 8 7 . 2 , - 2 8 . 4 )

- 1 0 8 . 8 , - 3 1 . 6( - 9 0 . 6 , - 4 5 . 8 )

I D B e t a F u n c t i o n s , yx , [ m ] 2 . 5 3 , 3 . 9 9( 2 . 7 6 , 3 . 9 7 )

4 . 6 5 , 2 . 3 7

D a m p i n g P a r t i t i o n F u n c t i o n s , J x , J e 1 . 1 6 , 1 . 8 4 5( 1 . 0 7 , 1 . 9 3 )

1 . 0 4 4 , 1 . 9 5 6

D y n a m i c A p e r t u r e [ X Y ] [ n o e r r o r s ] > [ 1 3 x 1 4 m m ] > [ 7 x 4 m m ]( > [ 1 7 x 7 m m ] )

E n e r g y L o s s i n D i p o l e s U o [ M e V / t u r n ] 0 . 8 9 3 0 . 9 3 8V r f [ M V ] 2 1 . 5 5

R F A c c e p t a n c e , R F [ % ] 3 3

B u n c h l e n g t h , l 0 [ m m , p s ] 4 , 1 3 . 3 3 . 3 , 1 1

N a t u r a l E n e r g y S p r e a d [ % ] 0 . 0 9 4 4( 0 . 0 9 2 3 )

0 . 0 9 4


Lattice Design for NSLS-IILattice Design for NSLS-II

• Design Goals and Lattice requirements

• Choice of Linear Lattice and beam parameters design

TBA vs DBA

• Dynamic aperture and sextupole tuning

• Longitudinal parameters and RF requirements

• Impact of undulators on beam parameters

• Conclusions and future research plans


WAYS TO LOW EMITTANCEWAYS TO LOW EMITTANCE

• Small bending, hence long circumference• TBA is better than DBA Cell• Combined function to reduce theta and increase DA• Non-zero dispersion in SS• Proper corrections to increase dynamical aperture• Additional corrections needed for for ID’s


•Design Goals and Lattice Design•Design Goals and Lattice DesignU ser R eq u irem en ts L a ttice D esig n G oa ls > 20 U ndu la to rs ( > 2m leng th ) > 23 ID 's o f > 4m Q uad-Q uad

P ho ton B eam tun ing 1 - 15 K eV R ing ene rgy = 3 G eV fo r S C UU sing ha rm onics up to 9 > 3 G eV fo r M G U fu ll cove rage

H igh B rilliance beam U ltra lo w em ittance , B eta va lues in ID

> 2 1 2 21 0 / sec / 0 .1 % / /P ho to n s m m m rad ( ~ 1 1 .5 , 1 0n ynm pm D F L @ 12K eV )

H igh flux and b righ tness Io ~ 500m A sto red beam curren t

L ife tim e and T op-O ff in jec tion L arge dynam ic and p

p

ape rtu re s

C ost constra in ts L im its size o f ring and in jection op tions

F utu re upgrade po ten tia l E R L 's N ear isochronous tune 71 0


Lattice Design ProcessLattice Design Process

User Requirements

Lattice Options

TBA DBA

Linear LatticeDesign

Longitudinal DynamicsImpact Undulators

Short & Long TermStability

Tolerance Errors

Non-Linear DistortionsDynamic Aperture

tracking


• Choice of Linear Lattice• Choice of Linear LatticeLattice Emittance related to bend angle in dipoles as

2 23x q q

x

HC CFJ

where F is a figure of merit for the lattice and 2

dN

.

TBA has one ME dipole ()m and two DBA dipoles ()d per cell2 3

( )4 15

q dMETBA DBA d

x

C

J

3: 3 1.44 1.44m d d m dOnly if and L L

For the same number of cells: 5MEDBA METBA

For Ncells(DBA) ~1.7 x Ncells(TBA) : MEDBA METBA

I.E. TBA(24) ~ DBA(40)


Initial Lattice Choice TBA(24)Initial Lattice Choice TBA(24)To meet users needs and future upgrade potential we chose a 24 period TBA.

This yields: 0.38 3METBA nmatGeV with bend ratio: 331.44m

bd

R

For simplicity set 2bR and L(ID) = 4 m Quad to Quad

S1 S2 SE SF SD 5 Sextupole Families- 3 Chrom, 2-Harm

C=523m, ChromX= -100, Emitt.= 1.5nm


•Dynamic ApertureAperture and Sextupole Tuning•Dynamic ApertureAperture and Sextupole Tuning

5 Sextupole families 3-chromatic and 2- harmonic

J. Bengtsson (TRACY & OPA) provided an expansion of the Hamiltonian up to 1st and 2nd order in thesextupole strength (b3L)

First Order terms are:

4 - C h r o m a t i c t e r m s w i t h p > 0 : 1 1 0 0 1 0 0 1 1 1h a n d h t h e n o r m a l c h r o m a t i c i t y f o r q u a d s a n d s e x t u p o l e s

2 0 0 0 1 0 0 2 0 1h a n d h d r i v e s 2 Q x a n d 2 Q y r e s o n a n c e s , /d d b e a t s a n d2 n d o r d e r c h r o m a t i c i t y

5 - p u r e l y g e o m e t r i c d r i v i n g t e r m s p = 0 : 2 1 0 0 0 1 0 1 1 0h a n d h d r i v e Q x r e s o n a n c e s

3 0 0 0 0h d r i v e s t h e 3 Q x r e s o n a n c e s

1 0 2 0 0 1 0 0 2 0h a n d h d r i v e s t h e Q x + 2 Q y a n d Q x - 2 Q y c o u p l i n g r e s o n a n c e s

T h e i n n e r p r o d u c t s o f t h e s e d r i v i n g t e r m s y i e l d s t h e t h r e e t u n e s h i f t s w i t h a m p l i t u d e s .

/ , / , /x x x y y yd Q d J d Q d J a n d d Q d J


Optimize 2nd order Tune ShiftsOptimize 2nd order Tune Shifts


Dynamic Aperture from tracking Dynamic Aperture from tracking DA > ( 11 x 11mm)

Nsigma>( 544 x 7700)

Real aperture adequate for injection

without breaking periodicity

FFT of tracked particles yields

real tune shift with amplitude

Shows higher order tune shifts

dominate > 4-5 mm (4.4um)


Pi-Transformer 2nd Order CancellationPi-Transformer 2nd Order Cancellation2nd order geometric terms cancel if identical sextupoles are separated by ( )M s I

I.E. Pi - transformer(2 1)

2

nQ

TBA lattice tunes are Qx=1.56 /cell and Qy=0.56/cell this should give partial cancellation.

+2 sextupole=

7 sextupole

families


Multi-cell Cancellation not HelpingMulti-cell Cancellation not Helping

7 families of sextupoles tuned

Shows better cancellation

But real tune shifts still big

And quadratic in Ax and Ay

DA not improved


New Direction: Lattice Choice Revisited New Direction: Lattice Choice Revisited New user requirement longer undulators and injection straight

7m Quad to Quad length with space for bump in triplet

Reconsider lattice choice for TBAStorage Ring APS ESRF ELETTRA DIAMOND SOLEIL Xray SLSLattice Type DBA DBA EDBA DBA DBnA DBA TBANumber of Cells 40 32 12 24 16.00 8 12Number dipoles 80 64 24 48 32.00 16 36Max. Energy [GeV] 7 6 2 3 2.75 2.8 2.4Circumference [m] 1104 846 259.2 561 354.00 170 288.00Emittance 3 GeV[nm]

1.29 1.75 15.9 6.5 4.44** 147 7.8

Min. Emittance [nm] 0.41 0.81 15.3 1.91 6.45 51.7 3

Ratio Emittance Minimum Emitt.

3.15 2.16 1.04 3.4 2.84 2.6

Qx/cell 0.88 1.13 1.19 1.095 1.14 1.14 1.7Qy/cell 0.36 0.35 0.69 0.509 0.64 0.517 0.68H Chromaticity -65.00 -114.90 -40.4 -71 -3.21 -22.4 -65.90V Chromaticity -27.00 -32.61 -13.3 -35 -1.43 -16.5 -20.85

Phi Dip-Dip [deg] 70.5 79.3 71.2 84.9 55.84


Reconsider DBA(28)Reconsider DBA(28)Scaling ELETTRA's achieved emittance to 28 periods

should yield 1.27nm at 3GeV

DBA Cell for APS DBA Cell for ELETTRA

2QF

QD QD

Zero Gradient Dipoles

QF QD

High Vertically Focusing Gradient Dipoles

Jx =1.45


DBA(28) Lattice with 7m ID’sDBA(28) Lattice with 7m ID’sEnhanced DBA lattice with high gradient dipoles developed

with circumference C= 630m, mostly due to ID length

EDBA(28) Achromatic lattice EDBA(28) non-Achromatic lattice


Sextupole Tuning yields large DASextupole Tuning yields large DA

Dynamic Aperture

increases by minimizing

sextupole driving terms

DA > (13 x 14mm)

DA is large enough

to consider injection

without breaking

28 period lattice


Momentum aperture also largeMomentum aperture also large

Chromaticity correction yields +/- 3% with 3Qx resonance at >+3%


Reconsidered TBA(24) LatticeReconsidered TBA(24) LatticeTBA lattice with 7m ID’s and better magnet spacing

increased C= 620m, mostly due to ID length


Sextupole tuning harder to optimizeSextupole tuning harder to optimize

Large higher order tune shiftsmake improvement in DA

less predictable with existingexpansion of Hamiltonian


Adding a family of sextupolesAdding a family of sextupolesAdding a 4th family of chromatic sextupoles and linear lattice

tuning for reduced horizontal chromaticityyields large improvement in DA > (17 x 7 mm)enough for injection and starting error analysis


•Longitudinal parameters and RF •Longitudinal parameters and RF The low emittance lattices have major impact on longitudinal parameters of

the beam through the small value of the momentum compaction factor.

RF Bucket Height RF RF

1

E V

E

Bunch length 1

Momentum Compaction factor ~ 1 2

dC

C

Second stable bucket with energy separation12 1

2

E

E

When RF 12E E

E 2 E

buckets distort and energy acceptance is

asymmetric reducing lifetime

DBA(28) TBA(24)

1 4

1.7110

4

0.81510

12E

E

0.48 0.06 <- Problem for 3%

RF bucket height


•Undulator Impact on Lattice Properties•Undulator Impact on Lattice PropertiesChanges of the beam properties were calculated using 4 dipole-2 drift model for undulators in

lattice programs Winagile and OPA

These have the appropriate rms orbit in the undulators and were compared to analytic models which ignore I4 dependence.

Parameter \ Lattice EDBA-28 EDBA-28 TBA-24 TBA-24

Undulator [ u , Kmax] 19mm , 1.85 15mm , 2.24 19mm , 1.85 15mm , 2.24

unddipole / 0.836 1.28 0.796 1.22

Energy loss Undulator(KeV) 12.46 29.48 12.46 29.48

Change in natural emittance -1.15 % -2.56 % -1.21 % -2.69 %

Change in energy spread -0.163 % 0.29 % -0.143 % 0.27 %

Vertical tune shift dQy 0.00355 0.0084 0.00218 0.00517

Vertical chromaticity change -0.0051 -0.0186 -0.0043 -0.0123

Fractional change in 1 60.6 10 61.2 10 61.1 10 62.4 10

Change damping time x [ms] -0.142 -0.316 -0.154 -0.341

y [ms] -0.187 -0.412 -0.167 -0.370

E [ms] -0.109 -0.239 -0.087 -0.193

Calculated change of lattice parameter for per 2m undulator

Tune shift may require some compensation with 20 undulators at Kmax


•Conclusions and Future Directions•Conclusions and Future Directions

•TBA-24 preferred lattice: Lower emittance (achromatic), ERL and super-bend

upgrade potential, lower DA and smaller

•DBA-28 Larger DA and emittance, similar emittance (non-achromatic),

less upgrade potential

•Need to address small DA issues for all lattices:

COSY Infinity, PTC, etc. to address nonlinear tune shifts

Develop multi-cell cancellation for interleaved sextupole

Try octupoles to reduce higher order tune shift with amplitude

•Plan to address tolerance errors: alignment, gradient, multipoles

•R&D effort: higher gradient dipoles, longer ID’s


Facility LayoutFacility Layout

Building Area Area [SF]First Floor Second Floor Total

Linac Vault & Klystron Gallery 12,493 6,068 18,561Utility Corridor 14,578 14,578Accelerator Tunnel 51,563 51,563Experimental Floor 111,230 111,230Office/Lab 64,173 64,173 128,346Office Block 11,055 8,945 20,000TOTAL 265,092 79,186 344,278

Linac Vault & Klystron GalleryUtility Corridor

Accelerator Tunnel

Experimental FloorOffice/Lab SpaceOffice

Block

IR Ring

60 m Long Beamlines


SitingSiting

NSLS-IICFN

NSLS

Parking

N

S

EW


Average X-ray BrightnessAverage X-ray Brightness

NSLS NSLS-II Gain

X25 U14 3x104

BM U14 5x106

BM BM 102

X1 U40 103

U5 U100 102-103

NSLS NSLS-II

# Und 5 21+

# BM 30 24

101 102 103 104 1051012

1013

1014

1015

1016

1017

1018

1019

1020

1021 U28

W60

U100

U13

U5

VBM

X17

XBM

X29X25

X1

BM

U40

Ave

rage

Brig

htne

ss[P

hot/

(sec

-0.1

%bw

-mm

2 -mra

d2 )]

Photon Energy (eV)

U14


Average X-ray FluxAverage X-ray Flux

NSLS NSLS-II Gain

X25 U14 20

BM U14 300

BM BM 2

X1 U40 20

U5 U100 2-3101 102 103 104 105

1012

1013

1014

1015

1016 U28

W60

U40

U13U5

VBM

X17

X25

XBM

BM X29

X1

U14

U100

Flu

x[P

hot/

(sec

-0.1

%bw

)]

Photon Energy (eV)


NSLS-II: World Leading BrightnessNSLS-II: World Leading Brightness

Current NSLS is off this chart at lower values

102 103 1041017

1018

1019

1020

1021 NSLS-II

APS

ALS

ESRF

APS Upgrade

ALS Upgrade

DIAMOND

Brig

htn

ess

[Ph

ot/

(se

c-0

.1%

bw

-mm

2 -mra

d2 )]

Photon Energy (eV)


NSLS-II: World Leading FluxNSLS-II: World Leading Flux

102 103 1041014

1015

1016

APS Upgrade

APSESRF

ALS

ALS Upgrade

DIAMOND

NSLS-II

Flu

x[P

ho

t/(s

ec-

0.1

%b

w)]

Photon Energy (eV)


NSLS-II: World Leading InfraredBrightness and Flux

NSLS-II: World Leading InfraredBrightness and Flux

1 10 100 10001012

1013

1014

10000 1000 100 1000 10

Frequency (cm-1)F

lux

[Ph

ot/

(se

c-0

.1%

bw

)]

Wavelength ( m )

NSLS-II IR RING

ESRF

DIAMOND

SOLEIL


NSLS-II Beamlines and InstrumentationNSLS-II Beamlines and Instrumentation

Tentative Insertion Device Beamline Plan

5 Macromolecular Crystallography 1 Coherent X-ray Scattering1 X-ray Micro-beam diffraction 1 Small angle x-ray scattering 1 Materials science/time-resolved 1 Inelastic x-ray scattering1 Resonant/Magnetic x-ray scattering 2 Superconducting Wiggler (6 beamlines)4 Soft x-ray undulator beamlines 4 To be determined

Optimized and Unique Endstation Instrumentation

Automation, RoboticsUltra-High PressuresUltra-High Magnetic FieldsVery Low TemperaturesAdvanced, efficient, high thoughput, large area detectors Pixel Array

Detector


FTE –Years : 531TEC: $393M FY04TPC: $424M FY04

2005 2006 2007 2008 2009 2010 2011 2012 Fiscal Year

PED OPERATIONSCONSTRUCTION

NSLS-II Preliminary Project ProfileNSLS-II Preliminary Project Profile

CD LLP CO

Conceptual Design

Project Engineering

& Design

Long Lead Procurement

Construction Commissioning Operations!


NSLS-IIThe Future National Synchrotron Light Source

NSLS-IIThe Future National Synchrotron Light Source

Stay tuned for future development

Enabling “grand challenge” science

ACCELERATOR DESIGN OF THE NSLS-II SYNCHROTRON LIGHT SOURCE

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