Shintake, Summer 2008

Introduction to XFEL project in Japan
Accelerator Based X-ray Laserfor single molecular structural analysis
andFemtosecond time resolution
Tsumoru Shintake
representing all XFEL contributors

RIKEN/SPring-8

Current status
andFuture(1)SPring-8

8GeV XFEL(under construction)(2006~2010)

FEL Prototype Machine,
Succeeded in Lasing,June 2006“X-ray Free Electron Laser, XFEL”
National Project of Next-Generation Light Source

RIKEN-JASRI Joint-Project Team for
SPring-8 XFEL Construction

XFEL/SPring-8

T. Shintake@ SCSS & XFEL/SPring-8 2008

(photo 2007 Summer)

8 GeV SPring-8 Ring
since 1997

SCSS Test Accelerator
since 2006
Project Period

2006 ~ 2010

First X-ray Beam2011

E Beam Energy

8 GeV

Project Cost

~360 Oku-Yen

Main Accelerator

400 m on surface

Undulator Hall250 m, 5 lines

Experimental Hall

56 x 31 m

8 GeV XFEL
under construction
will start ~2011

T. Shintake@ Matter in Coherent Light 2008

8 GeV XFEL Construction

2008 January

Linac Tunnel
Undulator area has been
excavated to replace soft soil
to hard basement.

8 GeV XFEL Construction

T. Shintake@ SCSS & XFEL/SPring-8 2008

2008 May

400 m accelerator
accelerator

Undulator
Hall

Accelerator tunnel

AssemblyHall

Shintake, Summer 2008

Comparison of X-ray FELs
Projects

Euro-XFELLCLSXFEL/SPring8(SCSS)

Wavelength

6 – 0.085 nm

1.5 – 0.15 nm

6 – 0.08 nm

Beam Energy

10 - 20 GeV

14.3 GeV

2 - 8 GeV

Main Accelerator

Super Conducting

S-band Normal
Conducting

C-band Normal
Conducting

Accelerator Length
2.1 kmGradient x Active Length 23.5 MV/m x 900 m

1 km
19 MV/m x 800 m

400 m
35 MV/m x 230 m

Undulator Period
Total undulator Length

26 mm
133 m

30 mm
113 m

18 mm
90 m

Total Length
Undulator Lines (X-ray)

3.4 km3 (5)1.6 km
1 (5)700 m
1 (3), max 5

Construction Cost

850 M-Euro

380 M$

300 M$SCSS:SPring-8 Compact SASE Source•

Low Emittance Injector

Short Saturation Length•

High Gradient Accelerator

Short Accelerator Length

KEK C-band 35 MV/m x 30 m = 1 GeV•

Short Period Undulator

Lower Beam Energy
Short Saturation Length

Kitamura’s In-Vacuum Undulator : E = 1GeV, Ou = 15 mm, Ox = 3.6 nm

T. Shintake@ SCSS & XFEL/SPring-8 2008

Expected Performance of XFEL/SPring-8
Wavelength< 0.1 nmPeak Power~ 20 GW

X-ray Pulse
Length~ 20 fs

X-ray Pulse
Energy0.4 mJ

Photon Flux

2 x 1011 p/pulse

Peak Brightness

1 x 1033
p/mm2/mrad2/0.1% BW

X-ray Pulse
Repetition

10 ~ 3000 pps(50 bunch x 60 Hz)

Bunch per Pulse

1 ~ 50 (4.2 nsec spacing)e Beam8 GeV x 0.3 nC
0.8 πmm.mrad, 3 kA

Expected X-ray pulse of 0.1 nm(SIMPLEX simulation)

T. Shintake@ SCSS & XFEL/SPring-8 2008

C-band Accelerator for Multi-bunch Option

13,000 cells are under mass production.

T. Shintake, “Choke Mode Cavity”,
Jpn. J. Appl. Phys. Vol. 31 pp. L1567-L1570, November 1992

Higher Order Mode Damping forMulti-bunch operation.
Maximum 50 bunches x 1 nC, at 4.2 nsec spacing
3000 X-ray pulses / sec.
Sadao Miura, MITSUBISHI Heavy Ind, April 2008

Mass-production of
128 tubes of the C-band Accelerating
Structure for 8 GeV linac.
@ MITSUBISHI Heavy Ind.

T. Shintake@ SCSS & XFEL/SPring-8 2008

Shintake, Summer 2008

Normal conducting v.s. super-conducting machine• (1) Super conducting accelerator is three or four times more expensive
than normal conducting accelerator.
• (2) FEL is basically pulse machine, and there is no reason to make it CW
machine. If you have CW FEL at X-ray, it becomes a weapon, and not
useful for scientific research tool, it average power is strong enough toburn verything.
• (3) CCD cameras for X-ray detector has certaing limit of reading time, it
slow. For example, 4k x 4k format CCD takes more than one minutes for
one frame reading time.
• (4) In the super conducting machie, the beam loading effect dominates
beam dynamics,thus in the bunch train the front part has dynamicchange before coming to the steady state, thus off energy particle irradiate
undulators.

Shintake, Summer 2008

MOVIE !

SPring-8 XFEL Accelerator and Undulator䌐䌁䌃䋲䋰䋰䋷

Peak Brilliance Evolution• Peak brilliance will be enhanced
by factor of 1010 from 3rdgeneration SR to XFEL.
• 1010 = 101 x 101 x 101 x 107= peak current by factor 10
x lowered emittance by 10
x energy spread lowered by 10
x interference effect 107 by
micro-bunching formation.

Science with X‐ray Free Electron Laser
Generation of extreme stateHigh brilliance
x109

Atomically-resolved imaging fornon-crystalline objects

XFEL

Spatialcoherence
100%

Ultrafast pulse< 100 fs

Probing of ultrafast
chemical reaction &phase transition1

Coherent diffraction imaging
Diffraction image
XFEL

Focusing
deviceReal image (atomic resolution)
SamplePhase retrieval by iterative algorithm
Target: Single molecule2

Shintake, Summer 2008

Why 1 Angstrom?
• Photo-ionization becomes lower as
X-ray energy.
• Around 1 A, 8 keV, photo-ionization
becomes low enough to see
coherent scattering.
• Spatial resolution becomes a few
Angstrom, which resolves
macromolecular crystal in biology.
Æ Imaging, crystallography•water window (2.3-4.4nm light) is
also another candidate.
( a few micron-meter thick water)

Cross-section of X-ray with Carbon

Sample damage with XFEL irradiation

Neutze et al, Nature, 2000

3

Shintake, Summer 2008

Who is Shintake?

@ SCSS tunnel
Test Accelerator for XFEL•

Date of Birth 1955, Miyazaki, Kyushu Japan•

1992~1996 FFTB – SLAC “Spot Size Monitor”(Shintake Monitor) 60 nm e with 1 μm wave•

1996~2000 “C-band R&D” for LC at KEK 5 cm
wave.

•

2000~2006 SCSS R&D Leader e- beam•

2006 First Lasing at SCSS Prototype
Accelerator 49 nm wave•

2006~ Now constructing 8 GeV XFEL/SPring-8
for 0..1 nmm wave

Shintake, Summer 2008

Shintake, Summer 2008

KYUSHUShintake, Summer 2008

MIYAZAKIShintake, Summer 2008

Shintake, Summer 2008

Shintake, Summer 2008

Shintake, Summer 2008

Shintake, Summer 2008

Design accelerator as creating images like art

Shintake, Summer 2008

Klystron Modulator for
C-band, S-band 50 MW Klystrons

Shintake, Summer 2008

50 MW Klystron and Modulator for XFELMax RF power : 50 MW@C-band and S-band
Max Pulse Power: 110 MW
Max Rep Rate : 60 pps
Size : 1m x 1m x 1.7 m
Total Weight : 4.5 ton
Insulation oil filled.
Water cooled.
Perfect EM noise shield.
Ready for mass production of 70 units.

Shintake, Summer 2008

Before XFEL

1996~2000 C-band R&D at KEK
C-band accelerator runs at 37 MV/m

1992~1996
FFTB at SLAC
Laser interferometer for
Spot size measurement.

Shintake, Summer 2008

Technology transfer
Year of 2000 ~KEK C-band

High energy e+e- collider

SPring-8 XFEL

Photon Science

1DQRPHWHU%HDP6L]H0HDVXUHPHQW                    
76KLQWDNH   

([SHULPHQWDO7HVWDW))7%
' # '     (        !"!!#$)  *+,) $- ( 

%& 

Undurator
y
a
r
X

on
i
t
a
adi

R

Magnetic
Field

m

r

ct
e
r
E

ea
B
on

Permanent Magnets

Shintake, Summer 2008

Feeling & Experience are very important in science.

Radiation2D simulator gives you reality as if
you are in front ofrunning noisy electron.

Radiation2d,
available from (freeware)

http://ShintakeLab.com

Freeware Radiation2D is available at

http://ShintakeLab.com

July 䋲䋰䋰䋷, StockholmInterference EffectShintake, Summer 2008

Physical Origin of Micro-bunching (FEL Action)• Undulator field produces curved trajectory. From this slope, thetangential component of EM wave creates longitudinal field.

Radiation

E

ory
t
c
raje
T
ron
t
c
Ele

α

Radiation Axis

E// = E sin(α) ~ 1/γ
E// creates micro-bunching.

FEL Power

Saturation

Exponential
SignalAmplification

SeedingorInfinitely Long
Undulator

Seeding

Shot Noise

Distance Along Undulator

T. Shintake
2007.01

What Undulator does? Scattering Undulator Wave
Laboratory Frame

Undulator

T. Shintake, 2006

Electron Rest Frame
Undulator becomes
Plane Wave
ElectronElectron

Oscillates

/γ

u
1.5 m

u
30 mm
10 GeV

Dipole Radiation
E

Doppler Effect

=

/2γ

u

/γ

2

u

1/2γ
0.4 A

P
Thomson Scattering

Crystal Diffraction Analogy
Radiation Pattern

Scattering by Electron

SRI2006 Shintake
T. Shintake, 2006

Power on Screen

π/2

Random multiple electrons

Speckleλ'θ=0yWave diffraction by
non-crystal material
Crystal Structure
xy-random, only z is regular.
X

Z

Screen

−π/2

λ'

x

Bragg Diffraction

θ=0
y

Y

λ'=4 μm

Bragg Diffraction

Screen−π/2xFrom Cavity Type FEL to SASE-FEL
from Linac or storage ringe-beamUndulator

MirrorConventional FEL

Electrons

Microbunching

Optical wave
(visible or infra-red)

Undulator

UV or X-ray

SASE-FEL
Linac

Electrongun

e-beame-beamElectrons

Microbunching

X-ray

Shintake, Summer 2008

We need low emittance beam and high peak current

E. L. Saldim, E. A. Schneidmiller and M. V. Yurkov, Opt. Commun. 235 (2004) 415• For 0.1 nm, and L =< 10 m (Saturation ~100 m)• Beam emittance ~ 1 π.mm.mrad (normalized, slice)• Peak current ~ a few kilo Amp.

before the “emittance”•

Such Beam Source Should be

Stable………charge, energy, pointing,– important for the machine tuning and performance.
– stable X-ray beam delivery to the user.
(SASE fluctuation can be reduced by seeding )•Clean ………no halo, no dark current(high field on cathode such as 100 MV/m will not be good).

– important for• undulator protection• accurate beam position monitoring•

Uniform ………current density– eliminate gain variation due to local lasing.
– deliver an uniform and stable X-ray beam to the user.

•

Maintenance Free

Like a Full Moon(stable and clean )Use Small Size Cathode…First Strategy for smaller thermal emittance• Thermionic cathode

3mm diameter cathode (CeB6)
is used in a low emittance injector.
(SCSS SPring-8/RIKEN)
Operating Temperature 1450°C

we

3
k BT
2

223 meV

Thermal Emittance

H xN• RF photo-cathode injector.

J rc
2

k BT
m0 c 20.4 ʌ mm-mrad0.28 S mm-mrad/mm

Today’s RF photo injectors use ~ 1 mm spot radius.

H xN

J rc
2

k BTe
m0 c 20.35 ʌ mm-mradSame order!

Te is “measured” effective electron temperature of copper
cathode using 266 nm laser (ref. 2). k Te = 0.27 eV (2360°C).

LaB6/CEBIX sections...

FEI Beam Technology Division is the world's largest supplier of
LaB6 and CeBix cathodes and material. FEI maintains apartnership with each electron beam instrument manufacturer
to ensure our cathodes meet the requirements of theequipment and application. Included with each cathode is ahandling and operating guideline for the specific instrument. FEI maintains a large
inventory of cathodes, and orders are typically shipped the next day.
FEI Mini Vogel Mount (MVM) cathodes provide stable, high-brightness, long-lifetime
operation for all major electron beam instruments. View FEI's standard parts for all
major electron beam instruments in use worldwide on our Applications Chart.
The superiority of the MVM comes from the simplicity of its design.

http://www.feibeamtech.com

Technical Challenge of Thermionic Injectors to
1 S mm-mrad emittance•this picture is copied from LCLS “Conceptual Design Report”, SLAC-R-593 UC-414•••

Eliminating control
grid from cathode.
Smaller size cathode,from 8 mm to 3 mmdiameter.
Higher gun voltage,
150 kV to 500 kV.
Using single crystal
CeB6 cathode.

Shintake, Summer 2008

FEL Map
copied from M. Ferrario, "OVERVIEW OF FEL INJECTORS“, EPAC06

Shintake, Summer 2008

How to obtain such high quality beam•RF-photocathode gun + magnetic bunch compression
RF-Photocathode gun 0.5 nC, 10 psec, 50 A

Æ Chicane Compression 1/100 Æ 100 fsec, 5 kA•

Thermionic gun + velocity bunching + magnetic bunch compression
Thermionic gun 0.5 nC, 500 psec, 1 A
ÆVelocity Bunching 1/20 Æ 20 psec, 20 A

Æ Chicane Compression 1/150 Æ 150 fsec, 3 kA

Big technical challenge!

SCSS Test Accelerator Performance

T. Shintake@ SCSS & XFEL/SPring-8 2008•••

2006 First lasing at 49 nm
2007 Full saturation at 60 nm
2008 User operation statC-bandaccelerator

500 kV Pulse electron gun
CeB6 Thermionic cathodeBeam current 1 Amp.

238 MHzbuncher

476 MHzbooster

In-vacuum
undulator

S-bandbuncherE-beamCharge: 0.3 nC
Emittance: 0.7 π.mm.mrad(measured at undulator)
Four C-band accelerators
1.8 m x 4
Emax = 37 MV/m
Energy = 250 MeV
In-Vacuum Undulators
Period = 15 mm, K=1.3
Two 4.5 m long.

Shintake, Summer 2008

About our SCSS & XFEL/SPring-8
All home made technology• The thermionic electron gun• Low emittance injector based on “Adiabatic Bunch
Compression”• C-band high gradient accelerator (35 MV/m)• In-vacuum undulator

Shintake, Summer 2008

Remove Solenoid Æ Separate Function Machine

T. Shintake, FEL06

CeB6 Thermionic Gun provides stable beam.

Beam Profile
CCD Image
Scale 10 mm

250 MeV Compressor

500 kV Gun

50 MeV Injector Out

Undulator Input

Undulator Output

July 䋲䋰䋰䋷, StockholmFirst Lasing at SCSS Prototype Accelerator.
June 15, 2006

Shintake, Summer 2008

First Lasing at SCSS Prototype Accelerator.

•
•
•
•
•

The first lasing: 49 nm
E-beam energy : 250 MeV
Bunch charge: 0.25 nC
Bunch length: (< 1 pse)Peak Current (> 300 A)•

At moment spectrum
width 0.5 nm is dominatedby e-beam energy
fluctuation ~ 0.2%.

Shintake, Summer 2008

First Lasing at SCSS Prototype Accelerator.
•
•
•
•
•
•

•

The first lasing: 49 nm
E-beam energy : 250
MeV
Bunch charge: 0.25 nC
Bunch length: (< 1 pse)Peak Current (> 300 A)
Laser pulse length has
not yet measured, (willbe ~ 100 fsec).
Peak power estimation
assumed 1 psec width.

SCIENCE

Thinking big. Tsumoro
Shintake with a prototype
XFEL at SPring-8.

MATERIALS SCIENCE

Japanese Latecomer Joins Race
To Build a Hard X-ray Laser
X-ray free-electron lasers are the next big thing in high-energy probes of matter.
With U.S. and European machines in the works, Japan wants into the club
SAYO, HYOGO PREFECTURE, JAPAN—It’s thescientific version of keeping up with theJoneses. Once researchers in one region plana big, new experimental device, researchers
everywhere want their own. The latest examp le: x-ray free-electron lasers (XFELs),
which promise beams that are vastly brighter
and with higher energy and shorter pulses
than today’s workhorse synchrotron x-rays.
These “hard” x-ray wavelengths—down tobroad interest for science, it is no surprise that
[researchers] in three regions of the world wantto have a facility of their own,” says Reinhard
Brinkmann, who leads the European effort
based at the German Electron Synchrotron(DESY) research center in Hamburg. “Freeelectron lasers are amazing things which herald a new era in photon science,” says Janos
Hajdu, a synchrotron radiation specialist at
Uppsala University in Sweden.

VOL 314

3 NOVEMBER 2006

or oscillating in lockstep—a quality missing
from synchrotron light.
Although all three planned systems sharethe same basic setup, subtle differences give
each of them strengths and weaknesses. “Thefinal targets of the XFEL projects are the same,but the means are different,” says Tsumoru
Shintake, who heads accelerator development
for Japan’s XFEL.
The first project to come online will be
Stanford’s LCLS. Much of the key researchunderpinning XFELs was done at SLAC
beginning in the early 1990s. And SLAC got ahead start by using a 1-kilometer stretch of its
now-idled linear accelerator, or linac. The
SLAC group estimates that reusing its linac
has saved more than $300 million, giving a
total construction cost of $379 million. LCLS
will have one undulator providing hard and soft
x-rays to up to six experimental stations.
Galayda says the group expects to generate its
first x-rays by July 2008 and to start experiments by March 2009.
Japan’s entry is the SPring-8 Compact
SASE Source (SCSS), just now getting underrconstruction here. Latecomers to the field, theteam is using some homegrown technology to
cut cost and size. “We’re taking the first step
toward making XFELs smaller and cheaper somore [institutions] can consider developing
their own,” boasts SCSS project leader Tetsuya
Ishikawa. Whereas the other two machines will
generate electrons by firing a laser at a metaltarget, the SCSS heats a cathode to produce
electrons. Eliminating the laser simplifies thesystem but requires careful compression of thecloud of electrons before they go into the linac.
The wavelength of the output x-rays is a

T. Shintake@ SCSS & XFEL/SPring-8 2008

Shintake, Summer 2008

Stability of SASE Intensity

Intensity variation = 11%(1σ)

50 nm

Shintake, Summer 2008

Evaluation of Slice Emittance
The normalized emittance at the lasing slice isestimated to be 0.7πmm.mrad !
Measured Density Profile

T. Shintake@ SCSS & XFEL/SPring-8 2008

SCSS Test Accelerator Performance• Running Always in Saturation Mode
– 50~60 nm (wavelength is limited by accelerator energy)– 30 uJ/pulse energy– 200 fs pulse length– E-beam 250 MeV, 250 A peak, 0.3 nC, < 1 psecFWHM, 20 pps• E-beam Emittance in the undulator is 0.7 π.mm.mrad– Determined from FEL gain measurement.

2008/01/28

T. Shintake@ SCSS & XFEL/SPring-8 2008
First experience, but team
did nice work.

We replaced CeB6 crystal in SCSS accelerator, after 20,000 hour operation.

Anode flange had color change.

CeB6 cathode after 20,000 hour use.

T. Shintake@ SCSS & XFEL/SPring-8 2008

It was found the cathode surface became concave of 0.2 mm deep from the initial flat surface.
It corresponds to evaporation speed of 10 nm/hour ( 10 nm/h x 20,000 h = 200 micron-meter)
Concave geometry made beam slightly focusing, but did not break emittance.
Electron microscope study showed (1) Surface is fairly smooth, (2) covered by carbon contamination(lowered electron emission).

T. Shintake@ SCSS & XFEL/SPring-8 2008

SCSS Test Accelerator User Run Has been Started in 2008••••

50~60 nm, 30 μJ/pulse
Multi-photon absorption
Coherent diffraction imaging
etc.

Experimental proposals at SCSS
High-contrast “coherent”
Biology & Medicine
imaging for biologicalsamples & nano-materials

EUV-FEL

Plasma physics

Physics
Creation of “extreme”
conditions in molecules&clusters

XFEL
R&D of XFEL experimental
technologies(timing, DAQ, etc..)

Chemistry

Nonlinear
spectroscopy“Snap-shot” probing ofchemical reaction

MEXT XFEL user application programs1

First experimental results from SCSS

Sato et al, Applied Physics Letters, April 2008

Strong EUV-FEL radiation produced Coulomb explosion of nitrogen moleculese-e-Two-photon
Double-ionization
Nitrogen ions after
Coulomb explosion

Coulomb explosion
Quadratic dependence onradiation intensity

2

T. Shintake@ SCSS & XFEL/SPring-8 2008

Status of 8 GeV XFEL/SPring-8 Construction• 2008 Summer, on schedule.
30% mass-production has done.
• 2009 April ~ , Accelerator tunnel construction will
be completed. We start machine installation• 2010 October. Accelerator construction complete.
• 2011 March, first e-beam to undulator• 2011 First lasing at < 1 nm
Æ start XFEL in operation.
Thank you!