1. The SPARX FEL Project
a source for coherent radiation production in the soft X-ray energy range

2. Main components of a Free Electron Laser
an accelerator providing a bunched relativistic electron beam
an undulator magnet
Electrons are not bound in atomic, molecular or solid-state levels but are moving freely in vacuum
For visible or infrared light an optical resonator can be used
At l below 100 nm the reflectivity of metals and other mirror coatings drops quickly to zero at normal incidence.
The principle of Self-Amplifified Spontaneous Emission (SASE) allows the realization of high-gain FELs at these short l‘s

3. The Principle of Self-Amplified Spontaneous Emission (SASE) X-FELs

4. Sparx

6. SPARC 500  100 nm commissioning FLASH 13  6.5 nm in operation
X-FEL ~ nm 2013
Fermi  40 nm 2010
Fermi2 40  10 nm 2011
SPARX 13  nm 2013
SPARC 500  100 nm commissioning
FLASH 13  6.5 nm in operation
100 nm ≈ 12 eV
h=6.6x10-34 J.s = 4.1 x eV.s
hn = 12 eV
= 12 eV/h ≈ 3 x s-1
l = c/n = 3 x 10 8ms-1/ 3 x s-1= m = 100 nm
l = [h(eV.s).c]/E(eV)=(12.4 x 10 -7eV.m)/E(eV)

7. Peak brightness (brilliance) versus pulse duration of various types of radiation sources

8. GE UK IT GE CH IT CH

9. Free-electron laser used in human brain/eye surgery
Use of the FEL to help remove a tumor from the brain of a patient. Unlike conventional lasers that produce light at given wavelengths, the FEL beam can be tuned through a wide spectrum of colors. That has allowed researchers to find the optimal wavelength (6.45µm) for cutting cleanly through living tissue.
Free-electron laser used in
human brain/eye surgery

10. Explosion of T4 Lysozyme
X-ray intensity, I(t) = 3 x 1012 (12 keV~1Å) photons per 100-nm diameter spot (3.8 x 106 photons per Å2)
Neutze et al. Nature (2000) 406:752

11. l = [h(eV.s).c]/E(eV)=(12.4 x 10 -7eV.m)/E(eV)

13. CCD detector recording a continuous diffraction pattern
A coherent diffraction pattern of the object
recorded from a single
25-femtosecond FEL pulse
Diffraction pattern from the subsequent pulse
Reconstructed image
No sign of radiation damage
The first pulse destroyed the object after recording the image

14. The image is then obtained by phase retrieval
Schematic depiction of single-particle coherent diffractive imaging with an XFEL pulse
K.J. Gaffney, H.N. Chapman Science 316, 1444 (2007)
plasma formation
Coulomb explosion
The image is then obtained by phase retrieval
3D diffraction data set is assembled from noisy diffraction patterns of identical particles in random and unknown orientations.

15. The Importance of the Phase Information
(b)
Fourier amplitude of (a)
+ Fourier phases of (b)
Fourier amplitude of (b)
+ Fourier phases of (a)

16. The First Experimental Demonstration
(b)
A Scanning Electron
Microscopy image
An oversampled diffraction pattern
(c)
Miao, Charalambous, Kirz & Sayre,
Nature 400, 342 (1999).
Image reconstructed from (b)

17. Flash Diffraction Imaging of Biological Samples
FLASH: 45 proposals 32 approved
Henry Chapman:
Flash Diffraction Imaging of Biological Samples

18. Tor Vergata FEL colloquia
March, 19, 2008 – Prof. Giorgio Margaritondo
Ecole Polytechnique Fédérale de Lausanne, Switzerland
  "Coherent Radiology - from Synchrotrons to Free Electron Lasers"
Aprile, 2, 2008 – Prof. Jianwei (John) Miao
Department of Physics and Astronomy, Univ. of California, USA  
"Coherent Scattering, Oversampling and Applications of X-ray Free Electron Lasers"
April, 23, 2008 – Prof. Janos Hajdu
Structural Biology Labs Biomedical Centre, Uppsala, Sweden
“TBA”
June, 18, 2008 – Prof. Massimo Altarelli 
European X-ray Free-Electron Laser Project Team, DESY,Germany
“The European X-ray Free-Electron Laser Project in Hamburg”