SLAC, July 22, 2013 1

An introduction

Claudio Pellegrini

SLAC, July 22, 2013 2

Looking at the universe• Our five senses give us information of the world, helping to

get the food we need, survive, acquire knowledge and avoid superstition, and hopefully have a pleasant and productive life.

• Vision is a most important sense. • With our eyes we can see macroscopic objects, near or not

too far from us, with a space and time resolution of about 0.1 mm, 0.1 sec and using visible light, a small part of the electromagnetic spectrum . These limitations defines how much of the world we can or cannot know, we can see the planets but not their satellites, a flea but not a bacterium.

SLAC, July 22, 2013 3

An improved vision sense

• In the first quarter of the 17th century, with the development of the telescope and the microscope, we started seeing things not seen before. Galileo saw and studied the satellites of Jupiter, the surface of the Moon, the many stars of the Milky Way.

• We could now see far away objects, still using visible light.

4

The beginning of microscopy

The earliest records of microscopic observations, mostly of a bee, date from 1625 and 1630 and were the work of Francesco Stelluti (1577-1653). They were published in Stelluti's Apiarium by the Accademia dei Lincei, in Rome.

Ten to fifteen years after the first telescopic observation, using an inverted telescope Stelluti started looking at what is too small to see with the naked eye.

SLAC, July 22, 2013 5

The microscope developed rapidly. Robert Hooke (1635-1703 ), in London, published his studies in Micrographia, his most well known work, in 1665. Hooke’s himself made the beautiful drawings from his observations. The book was published by the Royal Society.The space resolution improved, but not the time resolution or the radiation wavelengths used.

Hooke Microscopic Studies

SLAC, July 22, 2013 6May 23, 2005 6

On 8 November 1895, Roentgenwas working in his lab, studying the properties of a cardboard-shrouded electrical discharge tube. He was surprised to see that when the tube was operated, an object across the room began to glow. He gave the name “X-rays” to the invisible, mysterious and unknown agent.

12/22/1985Frau Roentgen’s Hand.

Another kind of light: X-rays

Roentgen won the first Nobel prize in physics in 1901. He did not take any patent on X-rays and their applications.

Dental X-ray, 2010Space-time resolution ~0.1 mm, 0.1s

SLAC, July 22, 2013 7

Another kind of light: lasers

NIF at LLNL, the largest laser: ~2MJ of infrared light, ~ 1 μm wavlength in tens of ns, 192 beams in a three-story high building the size of 3 football fields.

First ruby laser, 1960, MaimanHughes Laboratory in Malibu, California, ~0.7 μm, 3 ms pulse duration.

SLAC, July 22, 2013 8

Bella at LBNLBella at LBNL, 1 PW, 40 fs, Ti:sapphire.0.8 μm.This laser has been built to study particle acceleration, generation of X-rays, the interactions of electron and particle beams.

Lasers can reach the fs time scale at visible wavelength with coherence and very high peak power

SLAC, July 22, 2013 9

SLAC, July 22, 2013 10

To study atomic and molecular phenomena at their characteristic space and time scale, 1 Å, 1 fs we need an X-ray laser.Normal visible or near visible lasers use population inversion of electronic energy level in atoms at the 1-100 eV level, as can be done in Ti:sapphire or other crystals.An X-ray laser cannot be based on the excitation of electron energy level in atoms at the 1000-10,000 eV level, L and K electron band, but must use a different principle.

October 2, 2012 C. Pellegrini, H. Winick Symposium 11September 7, 2011

X-ray Free-electron laser:1992-2013

Flash: 4.45 nm, 0.3 mJ, 6/2010

LCLS, 1.5 Å, 4/2009, 1-3 mJ, few to 100 fs pulse duration, tens of GW of peak power, coherent X-rays.

SACLA, 0.8 Å, 6/2011Fermi@Elettra,43nm,12/2010

New projects: XFEL (2014), LCLS-II, Swiss X-FEL, Shangai, Korea, NGLS ….

SLAC, July 22, 2013 12

Femtochemistry

Nanoscale Dynamics in Condensed matter

Atomic Physics

Plasma and Warm Dense Matter, matter under extreme conditions

Structural Studies on SingleParticles and Biomolecules

FEL Science/Technology

Program developed by international team of scientists working with accelerator and laser physics communities

Aluminum plasma

10-4 10-2 1 10 2 10 4

classical plasma

dense plasma

high density matter

G =1

Density (g/cm-3)

G =10

G =100

t=0

t=

“the beginning.... not the end”

•SLAC-PUB-611

A research program with X-ray FELs

SLAC, July 22, 2013 13

Natively Inhibited Trypanosoma brucei Cathepsin B Structure Determined by Using an X-ray Laser,L. Redecke et al. Science 339, 227 (2013)

The Trypanosoma brucei cysteine protease cathepsin B (TbCatB), which is involved in host protein degradation, is a promising target to develop new treatments against sleeping sickness, a fatal disease caused by this protozoan parasite. … By combining two recent innovations, in vivo crystallization and serial femtosecondcrystallography, we obtained the room-temperature 2.1 angstrom resolution structure of the fully glycosylated precursor complex of TbCatB. The structure reveals the mechanism of native TbCatB inhibition and demonstrates that new biomolecular information can be obtained by the “diffraction-before-destruction” approach of x-ray free-electron lasers from hundreds of thousands of individual microcrystals.

SLAC, July 22, 2013 14

From the 17th century to today the space and time resolution of our “eyes” improved from 10-4 mm and 0.1 s to 10-10 m and 10-15 s, quite remarkable.We can see much more of the world and learn much more about it.

SLAC, July 22, 2013 15

Understanding and developing the physics of electron and photon beams to generate short wavelength, coherent radiation with femtosecond long pulses and high peak power leads to new and unique ways to explore matter at the atomic and molecular level and acquire new knowledge.

It will allow us to study the structure and dynamics of matter in non-crystalline state and far from equilibrium, the dynamics of chemical reactions at the femtosecond level, the functions of biological systems, the state of matter inside stars.

It is a fast growing and exciting field.

I wish you a good and productive week

Conclusions