X-ray lasers in biology - techniques

Professor John Spence, Arizona State University and Lawrence Berkeley Laboratory, USA

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John Spence is Regent's Professor of Physics at Arizona State University (where he teaches condensed matter physics) with a joint appointment at Lawrence Berkeley Laboratory. He completed his PhD at Melbourne University in Physics in 1973 and a post-doc at Oxford University in  Materials Science. He was awarded the Burger Medal of the American Crystallographic Association in 2011, and the Distinguished Scientist and Burton awards from the Microscopy Society of America. He is a Fellow of Churchill College Cambridge, of the APS and of the IOP in the UK. He was co-editor of Acta Cryst A for a decade, and is the author of texts on high-resolution electron microscopy (4th edition in press) and (with J.M. Zuo) on electron microdiffraction. A Festschrift volume of Ultramicroscopy appeared in 2011. John's lab at ASU has developed new scientific instruments and detectors for electron diffraction and imaging, and, since 2004 hydrated bioparticle delivery devices for X-ray lasers (with B. Doak and U. Weierstall). His current interests are biophysics and diffraction physics for the analysis of XFEL data. John is a member of the DOE's BESAC committee, which oversees research at the six US national laboratories.

Professor Spence gratefully acknowledges the award from the US National Science Foundation's Science and Technology Center for the use of X-ray lasers in Biology in support of this meeting.

Professor Henry Chapman, Center for Free-Electron Laser Science, DESY, Hamburg and University of Hamburg, Germany

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Henry Chapman is one of the founding directors of the Center for Free-Electron Laser Science (CFEL) at DESY and the University of Hamburg.  He led the development of coherent X-ray imaging and phase retrieval using short-pulse coherent X-ray sources, such as free-electron lasers.  His interest in this field began as a postdoc, collaborating with David Sayre on how to reconstruct images from the diffraction pattern of a non-periodic object.  At Lawrence Livermore National Lab he led a team to develop ab initio three-dimensional coherent diffractive imaging and single-particle imaging.  Using novel instrumentation of his design, the team made the first demonstration of imaging by “diffraction before destruction” at the FLASH soft X-ray FEL in Hamburg.  He invented and demonstrated a method, called time-delay femtosecond holography, to measure the X-ray induced Coulomb explosion to determine the limits of outrunning radiation damage. When the Linac Coherent Light Source opened in 2009 he led a large international collaboration to continue this work to the atomic scale with the method of serial femtosecond X-ray crystallography.  His current research is focused on developing this method and extending it to the smallest possible crystals: that is, single molecules.