Bright Lights on the HorizonFuture Perspectives for

Nuclear Resonant Scattering of

Synchrotron RadiationRalf Röhlsberger

HASYLAB @ DESY, Hamburg, Germany

•The Evolution of Brilliance

•Upgrade of Existing Sources

•Construction of New Sources:

•PETRA III and the XFEL

Evolution of Brilliance

http://www-hasylab.desy.de/facility/upgrade/main.htm

PETRA-III Upgrade

Schedule

• Submission of the Technical Design Report: March 2004

• Selection of the phase I beamlines: early Summer 2004

• Start of beamline R&D, prototyping: mid 2004

• Start of detailed beamline planning: end 2004/2005

user workshops on detailed beamline design

• Start of component production: 2006

• Start of reconstruction: mid 2007

• Installation of first beamlines: mid 2008

• Start of user operation: 2009

Storage Ring Particle energy = 6 GeV

Current = 100 mA (200 mA)

Emittance = 1 nmrad

Insertion Devices and Beamlines

13 independent undulators

1 undulator of 20 m length

Technical Design Report submitted:

22 experimental stations proposed,

including Nuclear Resonant Scattering

Operation

Number of bunches: 40 – 960

Bunch distance: 192 ns – 8 ns

Top-up operation mode

PETRA III - Facts and Figures

20 m undulator

General Experiment Support

Cryostats, high-magnetic fields, high-pressure cells,

furnaces, detectors (0,1,2 - dimensional), electronics,

mechanical components, lasers

Revolver – type with two magnet structures:

1) optimized for 14.4 keV (fundamental)

2) optimized for 21.5 – 30 keV (third harmonics)

NRS Beamline Proposed at PETRA-III

NRS from Isotopic Probe Layers using Microfocused Beams

Magnetic Properties :

Spin Structure and Magnetic Correlations in thin films and nanoparticles

Dynamic Properties :

Phonons at interfaces and in nanoparticles

Nuclear resonant photon correlation spectroscopy

Spot sizes well below 1m can be reached by application of focusing mirror optics

High-Resolution Monochromators at PETRA-III

Yu. V. Shvyd‘ko (2003)

Limits of Storage – Ring Based Sources

Development of New Radiation Sources

Beam properties reflect the equilibrium dynamics of particles in the ring, resulting from averaging over all revolutions

Particles are re-cycled

Design study: The Ultimate Storage Ring (USR)

Radiation is generated by single bunches passing through an undulator

Energy – Recovery Linear Accelerator (ERL)

Sub-Picosecond Pulsed Source (SPPS)

X-ray Free Electron Laser (XFEL)

X-Ray Free-Electron Lasers

• Synchrotron radiation– low emittance electron beam– relativistic electron energy– periodic acceleration of electron in

magnetic field of an undulator– collimated radiation– tunable by electron energy &

magnetic field

... at x-ray wavelengths

• no efficient reflectors exist

• lasing in a ‚single-pass‘

• Self-Amplified Spontaneous Emission (SASE)

SASE FEL

Undulator e-

log

(p

owe

r)

duration, length

SASE exponential growth and saturation

saturation length ~ 10 Lgain

gai

n ~

105

low gain exponential gain(high-gain linear regime)

P(z) = Po exp(z/Lgain)

non-linear

Electron bunch modulation

GENESIS - simulation for TTF parametersCourtesy - Sven Reiche (UCLA)

undulatorentrance

half-waysaturation

fullsaturation

Time structure of the XFEL radiation

Single bunches.Few bunches.Long trains.

Radiation parameters

Compared to 3rd generation

synchrotron radiation facilities,

the gain factors are• Peak brilliance 109 (FEL)• 104 (spont.)• Average brilliance 104 (FEL)• Degeneracy 109 (FEL)

109 Total increase106 FEL gain103 e-properties undulator length

Published science cases for FEL radiation Ultrashort duration of X-ray pulses High number of photons per pulse Coherent x-ray radiation

• Atoms, molecules, cluster• Plasma physics• Hard-condensed matter• Surface & interface studies• Materials science• Chemistry• Biology• Nonlinear phenomena & quantum optics• FEL physics

http://slac.stanford.edu/lclshttp://xfel.desy.de

2000-2002 TTF-1 (Hamburg)2000-2001 LEUTL (Argonne)

1980 initial paper

2008 LCLS (Stanford)

2012 European XFEL (Hamburg)

2004 VUV-FEL@ TTF

(Hamburg)

Roadmap towards an 0.086 nm XFEL

The European XFEL project

• Original proposal (March 2001) part of the TESLA project.

• In October 2002 an standalone version was proposed

• Germany agreed to propose a site and to cover 50% of the building cost.

• Technical parameters are currently reconsidered.

~ 2000m ~ 1200m

3 FEL and 2 beamlines for spontaneous synchrotron radiation with 10 independent experimental stations

The European XFEL at the DESY site

Towards the European XFELFeb 2003 BMBF indicates ‚green light‘ for European XFELOct 2003 European Strategy Forum for Research

Infrastructures evaluates Technical challengesDec 2003 XFEL enters EU Quickstart programme

Jan 2004 Formation of an European steering group • Working groups on technological issues• Working groups on administrative issues• Update of scientific case

End 2004 Start plan approval procedure at DESYWorkshops to define user/science requirements

Early 2005 European agreement on XFEL projectStart of project

2006 Start of construction2012 Start of commissioning

Diffusion, melting,ablation

Phonon-phonon scattering

Valence state excitations Te-h >> TL

no

n-t

he

rma

lth

erm

al

Equilibration (Te-h ~ TL)

Carrier-phonon scatteringTe-h , TL

10-15 s

10-12 s

10-9 s

10-6 s

Ultrafast Processes

NRS Experiments at the XFEL

Pump-probe investigations of dynamical phenomena

Excitations in artificial spin chains, solitons

Fast magnetic switching

Magnon spectroscopy,

Single – particle imaging

Use of complementary techniquesNeutron scattering, Magnetic x-ray scattering, Magneto-optics, Inelastic x-ray scattering, …

Non-equilibrium phenomena