MRI: Development of a Coherent and Incoherent X-Ray Facility at JILA: Ultrafast X-Ray Science and Technology at the Nanoscale

University Of Colorado At Boulder, Boulder CO

Investigators

Abstract

Advances in x-ray science and technology have resulted in breakthrough discoveries ranging from unraveling the structure of DNA and proteins, to visualizing atoms, molecules, and materials at the nanoscale. X-rays, by virtue of their short wavelength, are ideal probes of the nanoworld. X-rays can image small objects, penetrate thick samples, while the presence of elemental absorption edges in the soft x-ray region allow element and chemical-specific imaging of thick samples. An exciting recent advance is the ability to generate ultrafast coherent, laser-like, beams of x-rays from both large scale and small-scale setups. Facilities based on x-ray free-electron lasers are now coming on-line in the US, Europe and Japan, that will capture dynamic images of biomolecules or magnetic domains in a single burst of x-rays. Using the extreme nonlinear optical process of high harmonic generation, bright, laser-like, beams of extreme ultraviolet light at photon energies less than 100eV can be generated in a tabletop setup, by upconverting femtosecond laser beams to higher energy photons. Moreover, a major recent breakthrough at CU allows bright beams of soft x-rays to be extended to greater than 0.5keV experimentally, and in theory to 10keV, essentially enabling a coherent version of a soft x-ray tube. This was accomplished by driving the high harmonic process using mid-infrared driving lasers. The work will implement high flux, ultrafast, x-ray beams from 0.1 - 7keV, by driving high harmonic and laser plasma sources with high average power, infrared lasers. This project will employ leading-edge laser and x-ray science, where the ability to manipulate electrons on attosecond timescales using femtosecond lasers will be used to generate bright, coherent and incoherent beams of keV x-rays. The research that will be enabled will explore scientific and technological frontiers at the nanoscale. The broader impacts are that this effort will provide a facility for breakthrough research for a diverse group of students and faculty. A multidisciplinary team of junior and senior faculty and students from science and engineering are working together to develop a unique, world class, small-scale facility for ultrafast x-ray science and technology. All of the applications, including probing the limiting switching speed in magnetic materials, capturing thermal transport in nanostructures, following moleuclar and electron dynamics, and high resolution imaging, greatly benefit from using higher energy photons. The team includes experts in laser and x-ray science and technology, materials and nano science, mechanical and electrical engineering, and chemical and biochemical science.