ATSUTO ATSUTO SUZUKI SUZUKI (KEK)(KEK)

ICFA Seminar, ICFA Seminar, SLAC, October 31, 2008SLAC, October 31, 2008

Goal of Accelerator Science: To Answer Fundamental Questions

We humans have long been obsessed with four great questions: 

the nature of matter,the origins of the Universe,the nature of Life,the workings of mind. 

Herbert A. SimonNobel Laureate in Economics

from the Lecture in 1986

3

To Open up a New Horizon of Science

Innovations in Accelerator Technology

Universe

Accelerators have been and will be a powerful tool to challenge for answers to them.

Matter

Life

EnergyEnergy--upupPowerPower--upup

FasterFaster--timingtimingFinerFiner--sizesize

101033 xx

1000 x Higher Energy

1000 x Faster Timing1000 x Finer Resolution

LifeMatter

Universe

1000 x Higher Intensity

Powerful, but Possible,

or Prospective,or Dream

Technologies

Vast Fields

of Applications

5

PeV Accelerator

1 TeV=101 TeV=101212 eVeV“Standard model”

HiggsHiggsQuarksQuarksLeptonsLeptons

1000 times higher energy1000 times higher energy

““ New paradigmNew paradigm””

LeptogenesisLeptogenesis

SUSY breakingSUSY breaking

Extra dimensionExtra dimensionDark matterDark matter

SupersymmetrySupersymmetry

……….……….

AccelerationTechnology

1 PeV=1015 eV

(http://tesla.desy.de/~rasmus/media/Accelerator%20physics/slides/Livingston%20Plot%202.html)

When can we reach to 1 PeV ?

2030 2040 2050 2060

1013

1014

1015

ILC

When can we reach to 1 PeV ?

Laser plasma acceleratorexperiments

V. Yakimenko (BNL) and R. Ischebeck (SLAC), AAC2006 Summary report of WG4

ee--ee++ colliderscolliders

E=40 MV/m

E=200 MV/m

E=10 GV/m

Evolution of Accelerators and their Possibilities

2020s

2040s

2030s

ILC

Two-beam LC

Laser-plasma LC

2.5-5 GeV ERL

Superconducting L-band linac

Decelerating structure

Ultra‐HighVoltage STEM 

with Superconducting

RF cavity

Accelerator

10cm‐10GeV Plasma Channel Accelerator

Earth

Space debrismm waves

Earth-based space debris radar

Table-top high energyaccelerator

UltraUltra--High Voltage STEMHigh Voltage STEM(Scanning Transmission Electron Microscope)(Scanning Transmission Electron Microscope)

Full utilization of accelerator technology

Existing STEMhuge sizelinear opticsmore transmission power

•• compactcompact•• low costlow cost

•• high resolutionhigh resolution•• excellent transmission powerexcellent transmission power

•• versatileversatile•• well functionalwell functional

Successful achievements:J‐PARC Linac, ILC R&D, etc.

Advanced technology of digital RF control

Accelerator beam optics

Nonlinear optics

→ non‐axially symmetric optics

Superconducting RF acceleration 

CW stable beam

Explored Two-beam LC:TBA/FEL (X-Ka band) @ KEKTBA/RK (X-band)@LBNL/LLNLTBA/CLIC (X-Ka band)@CERN

Decelerating structure

Two-Beam Accelerator Applicati0on to Space Debris Radar SystemImpact Damage on International Space StationDistribution of cataloged space debris (~ 9,000 beyond σ = 100 cm)

LEO region

X band

Properties:• well-defined phase• well-shaped pulse trains• high peak power -> deep space• short wave length -> size σ ~ 1 cm

from LEO region to GEO region

Use of High Power Pulse μ-wavesfrom a TBA in Open Space

Low Earth Orbit (LEO)

Geostationary Orbit (GEO), v =10~100 km/s

< 2,000 km

~ 40,000 km

Tracking/Imaging Radar System

30 km (100μsec)

3,000 km(10msec)

Reference receiverantenna

~ 350 km

μ−wave pulse

(x,v) and σ

(v <10 km/s)

sweep

NASA, Orb. Deb. Qart. News July, 20008

Driving beamSeed μ−wave pulses TBATBA

Low Earth Orbit (LEO) Geostationary Orbit (GEO)

3D-PIC PWFA simulation by F. Tsung/UCLA(CERN Courier June 2007, P.28, C. Joshi)

Laser pulse Bubble

Electron

Particle Driven Plasma Acceleration

Laser Driven Plasma Acceleration

42GeV e-beam energy doubled byPLASMA WAKEFIELD ACCELERATORI. Blumenfeld et al., Nature 455, 741, 2007

Plasma wakefield in the “bubble” regime

Energy spectrum of E167 SLACPlasma Accelerator Experimentfor the 42 GeV electron beamafter passing through a 85 cm long plasma of density2.7x1017 cm-3

Energy spectrum of E167 SLACPlasma Accelerator Experimentfor the 42 GeV electron beamafter passing through a 85 cm long plasma of density2.7x1017 cm-3

0.56 GeV capillary accelerator experiment at CAEP/KEK

3cm gas-fill capillary

4cm ablative capillary

1 GeV capillary accelerator experiment at LBNL/Oxford U.

Intensity (arb.u.)

Div

erge

nce

Ang

le (m

rad)

Electron Beam Energy (MeV)

Intensity (arb.u.)

Stable electron beams and more high-energies from 1 cm gas jet

at GIST, Korea

100TW laser systemat Gwangju Institute ofScience and Technology

(N. Hafz et al., nature photonics, 2, 571, 2008)

Mean electron energy = 236.9 MeVSD/Mean E = 5 %Charge: ~100pC

Divergence angle: ~a few mrad Recent results at 50 TW

Recent results at 50 TW

Laser-driven table-top X-ray Free Electron Laser

Linac CoherentLight Source

Kilometer-scale X-ray FEL

Zone plate sample

Pin hole

Beam stop

CCD camera

Hologra

mCoherent X-ray

X-ray Holography Microscope

1000 times more powerful beam

1000 times more powerful beam

Super‐conducting AcceleratorTechnology

100 kW Beam Power100 kW Beam Power

100 MW Beam Power100 MW Beam Power

J‐PARC  Neutrino FactoryNeutrino Factory

Muon ColliderMuon Collider

Linear ColliderLinear Collider

Brighter neutron sourceBrighter neutron source

Nuclear waste processingNuclear waste processing

Inertial FusionInertial FusionMuon‐colliderNeutrino factory

Beam Power = Energy  x   Bunch Charge  x  Bunch Repetition

Beam PowerBeam Power

feasible solution : Acceleration by L‐band Superconducting Cavities,Continuous beam accelerated by Linac

ILC cavity orERL cavity

high power transfer to beam (small wall loss)

continuous acceleration (CW beam)

HOM damping, large bunch size 

High beam current

High field acceleration

Beam structure and RF power source

For example; taking 10nC/pulse,  10MHz repetition, CW : it is 100mA continuous beam,

developing 9‐cell SC with 40MV/m and using only 2‐cells,40MV/m x 2cell/9cell = 8.9 MV  energy gain 8.9MV x 100mA = 890kW power transfer to beam

developing 2MW CW RF power source, it deliver RF power to two 2‐cell cavities.

using this RF unit, 100, then, 100 x ( 2 x 8.9MeV) = 1.78 GeV beam energy

100 x ( 2 x 890kW) = 178MW beam powerwith 100m Linac length. 

beam time structure

Higher Order Mode (HOM) damped High Gradient Cavity

L‐band superconducting 2 cell cavity with damped port

ERL 2‐cell cavity for Injector line, as an example

CW beam

2MW CWRF power

500kW CWpower coupler

500kW CWcirculator

HOM dampers(TESLA type, KEKB type, ERL type)

Superconducting 2‐cellCavity ( 40MV/m )

Surface Polishing for High Gradient Cavities

To improve superconducting cavity performance, for example,

Remove Nb surface defects (surface steep steps should be < 1‐2µm )

Remove surface contamination ( 1‐2µm size contamination should be removed)

Develop fine EBW, fine EPandDevelop local grinder 

to remove local defectslocal grind tool

sponge wipe tool(direct physical cleaning inside of cell)

Develop rinse and HPR,andDevelop sponge wipe rinse

Candidate of possible Accelerator in Drawing

ILC cryomodules for LINAC, as an example

High intensity LINAC cryomodule with many RF power feed6mcryomodule

beam

RF powers

Brighter Neutron & Neutrino Sources

high gradient -> compactlow wall loss -> efficientCW operation -> high beam power

Spoke‐type cavity

superconducting rf technologyfor proton or ion linac

High β cavityRFQ

100MW‐class proton linac may be feasible; e.g., 5GeV×20mA.It is a single accelerator but not an injector.

Does not need H‐ ion source

Less beam loss

Modest peak current

Less requirement for target design

SNS Linac

KamiokaKamioka

J‐PARC Neutrino beam (about 1MW)

Very High Power Neutron/Muon Source

(> 10 MW)

Unprecedentedly High  Power CW Neutrino Beam

(100 MW)

Pulsed Mode CW Mode

Compact Neutron Source

Subcritical reactor alone

The dream of realizing accelerator driven (subcritical reactor) system andnuclear waste transmutation system comes true with 

high power superconducting linacs ! 

Fuel: Thorium

232Th232Th

MA: minor actinide

Electric power generation& nuclear transmutation

wasted nuclear fuels

Driver for Heavy Ion Inertial Fusion Program in US-VNL

G.B.Logan (VNL), presented at HIF2008, Tokyo Japan

0.73 A20 μsecHot-plate source

V - 50 MV Z=150 MeV

Induction Linac

V - 100 MV (150 m)Z=9~ 1 GeV

36 X drift compressorin neutralizing plasma

1 st stripper

Z=+1 -> +92nd Li stripperZ=+9 -> +35

Driver configuration (Horizontal)

Idea of Proton Driven Inertial Fusion :  DownIdea of Proton Driven Inertial Fusion :  Down

1000 x Higher Energy

1000 x Faster Timing1000 x Finer resolution

UniverseMatter

Life

1000 x Higher intensity

Future PF Accelerators

• Ultra – short light pulses : enable to visualize dynamics of moleculesand transient phenomena of materials  

• Ultra – small size beams  : provide powerful tools to probe biologicalcells or materials with an atomic precision

average brilliance

peak brilliance

repetition rate (Hz)

coherent fraction

bunch width(ps)

# of BLs

Remark

ERL ~1023 ~1026 1.3G ~20% 0.1~1 ~30 Non-perturbed measurement

SAS-EFEL ~1022~23 ~1033 100~1K 100% 0.1 ~1 One-shot

measurement

XFEL-O（Option)

~1027 ~1033 ~1M 100% 1 few Single mode FEL

(brilliance : photons/mm2/mrad2/0.1%/s @ 10 keV)

SASE-FEL

Functions of ERL, SASE-FEL & XFEL-O Functions of ERL, SASEFunctions of ERL, SASE--FEL & XFELFEL & XFEL--O O

ERL XFEL-O

10‐3  10‐6  10‐9

Beam‐size (m)

1010

1011

1012

1013

1014

Intensity

 (Pho

tons/s)

3rd SR  ERLXFEL 

Intensity vs. Beam‐size(schematic view)

1000 times shorter timeresolution

1000 times shorter timeresolution

1 ns = 10-9 s

Ribosome

Fast photo-switching of metal-to-insulatorphase ~ 1 ps

Femto‐sec BeamTechnology

Photosynthetic reaction in leaves~ 100 fs

Rhodopsin~200 fs 1 fs = 10-15 s

current light

sources

1 ps = 10-12 s

future light

sources

bunch-slicing

Photo‐induced phase transition(Strongly‐Correlated Electron Systems)

Chollet et al. (2005) Science 307, 86

Sub-pico-second photo-inducedmetal-insulator phase transition

- Application for a THz-switching device -

ERL will provide us following information!!

Structure?(X-ray diffraction)

Electronic state?(Photo-emission spectroscopy)

Domain formation?(X-ray Photon Correlation Spectroscopy)

(reflection)

Fe‐N bond length

Energy

400nm

~700ps

5T21A1

1MLCT

MLCT,LF

(LS)(HS)

76007400720070006800

difference

LS Transient

difference (+50ps)

Fe K-edge EXAFS

Inte

nsity

(arb

. uni

ts)

Photon Energy (eV)

Solar Cells and Photon‐Catalysts

CurrentCurrentSRSR

Future SRFuture SR

- How do molecules act after absorbing photons ? -

Rhodopsin absorbs light in ~ 200 fs in eye, and transmits visual information to brain in ms order.

Figures from THE CELL (4th edition)

Visual Sensing Cascade

200 fs

Visual Sensing and Photosynthesis

100 fs

Photochemical reaction center absorbs light in ~ 100 fs, and converts light to chemical energy.

Leaf, Chloroplast and Granum

1000 timeshigher spatialresolution

1000 timeshigher spatialresolution

1 pm

Nano beamTechnology

10 nm

cellular structurecellular structureand function ~ (1and function ~ (1--10) nm 10) nm

5 nm

catalytic chemistry~ 1 nm

extreme condition~ (1-10) nm

Nano-crystal ~ 1 nm

current light

sources

future light

sources

~100 nm

1 nm

Diffraction from a yeast cell Reconstructed imageD. Shapiro et. al. PNAS,102, (2005)

Cellular and sub-cellular imaging & elementary mapping inside cells

:New Insights on Real Cell Functions

Adapter proteins ClathrinKinesin and microtubule

Ribosome

Current ObservationsCurrent Observations

(crystallized inside colon bacillus)

Catalysis Chemistry

5 nm

40Å

in situ observation of active site (species) itself using nano beam

active site (species) of catalystsNano beams enable to evaluate

local structure and electronic state of active site (species) for various catalysts

Pd nanoclusterK. Kaneda, et al. J. Am. Chem. Soc. (2002)

J. Am. Chem. Soc. (2004) MCM-41 (zeolite)N. Ichikuni et al. (2005)

NaTaO3:La + NiO catalystA. Kudo, et al. J. Am. Chem. Soc. (2003)

Nano beam

Surface & Interface

Nano-size

Expectations of Novel Electronic State!

Nano Crystal of (3nm)3

---> 60％: Surface

Laser MBE

NanoNano--Beam : Charge, Spin and Orbital States of Beam : Charge, Spin and Orbital States of Single Layer or Single NanoSingle Layer or Single Nano--CrystalCrystal

Current SR(c)SrSr2+2+TiTi4+4+OO33

LaLa3+3+TiTi3+3+OO33

4 nm

Formation of (LaO)2 layers

LaLa3+3+TiTi3~4+3~4+OO33++dd

ERLXFEL

Application to the Earth & Planetary Science 

Lower mantle: 140GPa and 4600KCenter of the earth: 360GPa and 6000 K

Exploration of Earth’s Core

140GPa

4600Ｋ

360GPa

6000K ERL

High intense sub-micron focused beam gives information on the center of the earth.

High temperature and high pressure stateslike the Earth core

in small size  of materials at laboratory

Information on atomic, electric and magnetic structures

1000x Higher intensity1000x Finer resolution1000x FasterTiming1000x Higher Energy

LifeMatter

Universe

Ultra-high energy STEM, Space debris radar system, Table-top accelerator

Accelerator driven reactor, Nuclear transmutation, Inertial fusion

Compact neutron source

ERL, SASE-XFEL, XFEL-O

Induction acceleratorLaser Plasma accelerator

Superconducting RF cavity

Real cell imaging and mapping, …

Low temperature technology

Fast photo-switching technology, …

As  the  size  of  accelerator  science  projects  grows 

bigger  and  bigger  and  the  time  span  of  each  project 

becomes longer and longer, we can never conduct such 

research programs, unless we have  the strong support 

of taxpayers, and active contributions from researchers 

to society in general.  

Now it is time for us to make a serious commitment to 

solving  various  societal  issues  such  as  energy  and 

environmental  problems  through  cooperation  with 

industry and technology transfer to society, in addition 

to producing the highest level research outcomes.