The Indian Institute of Technology Bombay is organising an Institute Lecture on Friday, November 15, 2019. The details of the lecture are given below:
Speaker : Professor Justin Wark, Professor, Department of Physics, Oxford University and Fellow, Trinity College, UK
Title : "Science with X-Ray Free Electron Lasers"
Abstract: Just over a decade ago, the LCLS X-Ray Free Electron Laser started its operation. Since that time this so-called “4th generation light source” has had immense impact across many scientific disciplines including biology, materials science, chemistry, atomic and molecular physics, plasma physics, and planetary science. Several other machines around the world are now operational or planned. In this talk I will outline the main characteristics of this new type of x-ray source, and provide a few examples of the revolutionary science they are enabling, including in my own field of research, where for periods of time ranging from a few femtoseconds to nanoseconds we can create and diagnose, in a controlled manner, matter that is similar to that which exists half way to the centre of the sun, or towards the centre of giant planets. Further advances are imminent as a result of the start-up of the European XFEL, that pushes machine parameters even further.
About the speaker: Prof. Justin Wark started his Physics career as an undergraduate at Oxford, before studying at Imperial College, London, to pursue a PhD in Plasma Physics. From there he moved to the University of Rochester in upstate New York to undertake a postdoctoral fellowship at the Laboratory for Laser Energetics. Later he started a strong collaborations with scientists at Lawrence Livermore National Laboratory in California, which hosts the largest laser in the world: the National Ignition Facility (NIF). He returned to Oxford in 1988 to set up a research group working in high power laser-matter interactions. The lasers he uses are amongst the most powerful on earth: although they are only on for a brief fraction of a second, the peak power in the light is more than thirty times as powerful as the electrical output of the whole earth. Over the past few years he has also been one of the first UK researchers to use the new generation of x-ray lasers, which themselves are a billion times brighter than any other x-ray source in existence. These extraordinary machinespromise to revolutionise many areas of science – the wavelength of x-rays is short enough to allow us to ‘image’ atoms, and the femtosecond duration of the x-ray pulse is shorter than the fastest vibrational periods of atoms – these two attributes allow ‘molecular movies’ to be made.
Prof. Wark is a member of the LCLS at Slac, Stanford and a Fellow of the American Physical Society. His research interests lie in the theory, creation, and diagnosis of matter under extremes of temperature, density and pressure – conditions that are far beyond those found on earth, and only exist at the centre of the giant planets within our own solar system and beyond, or towards the centre of stars. He also uses the largest and most powerful optical and x-ray lasers to perform these experiments. The resulting pressures produced can be many tens of millions of atmospheres, and temperatures of millions of degrees. These ‘miniature stars and planets’ created within the laboratory have short lifetimes – sometimes only a few tens of femtoseconds, and within that brief time, all measurements must be made. Experimental data inform the fundamental theory of these dense, hot systems, and my research group also uses ab initio quantum simulations and complex atomic physics packages to model the underlying physics. Certain aspects of the work have direct relevance to the quest for laser-driven fusion energy. Prof. Wark is a professor at Physics Department, Oxford University and Fellow, Trinity College. His research interests are high-intensity light-matter interactions, ultrafast optical and x-ray pulses to probe exotic states of matter, High Energy Density Physics and Inertial Fusion Energy.