Society of Physics Students Lecture Series

6:00–7:00 pm KPTC 206

X-ray lasers – exploring the ultrasmall and ultrafast world
Linda Young, UChicago

In April 2009 the world’s first hard x-ray free electron laser (XFEL) was born.  This seminal achievement of accelerator and optical physics provides roughly a billion-fold increase in peak intensity for man-made sources of radiation at Ångstrom wavelengths, and, produces focused intensities of 1020 W/cm2 – far exceeding the atomic unit of intensity.  Early simulations using ultrafast and ultra-intense x-ray pulses suggested the feasibility of single molecule imaging via the “diffract-before-destroy” method and largely inspired the construction of XFELs. While this method has successfully been employed for nanocrystalline biological samples, the original goal of 3D imaging of complex non-periodic objects at atomic resolution remains elusive.  Underpinning atomistic imaging is an understanding of the fundamental interactions of x-ray radiation with matter in the new nonlinear regime provided by XFELs and required for “diffract-before-destroy”.  In this talk I will discuss how we have achieved the current understanding of light-matter interactions in this new regime and the new possibilities enabled by the new generation of XFELs that promise attosecond pulse durations.

May 13