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Full-Text Articles in Physics

Imaging Of Alignment And Structural Changes Of Carbon Disulfide Molecules Using Ultrafast Electron Diffraction, Jie Yang, Joshua Beck, Cornelis J. Uiterwaal, Martin Centurion Sep 2015

Imaging Of Alignment And Structural Changes Of Carbon Disulfide Molecules Using Ultrafast Electron Diffraction, Jie Yang, Joshua Beck, Cornelis J. Uiterwaal, Martin Centurion

Martin Centurion Publications

Imaging the structure of molecules in transient-excited states remains a challenge due to the extreme requirements for spatial and temporal resolution. Ultrafast electron diffraction from aligned molecules provides atomic resolution and allows for the retrieval of structural information without the need to rely on theoretical models. Here we use ultrafast electron diffraction from aligned molecules and femtosecond laser mass spectrometry to investigate the dynamics in carbon disulfide following the interaction with an intense femtosecond laser pulse. We observe that the degree of alignment reaches an upper limit at laser intensities below the ionization threshold, and find evidence of structural deformation, …


Gas-Phase Electron Diffraction From Laser-Aligned Molecules, Jie Yang, Martin Centurion Aug 2015

Gas-Phase Electron Diffraction From Laser-Aligned Molecules, Jie Yang, Martin Centurion

Martin Centurion Publications

Electron diffraction is a valuable tool to capture structural information from molecules in the gas phase. However, the information contained in the diffraction patterns is limited due to the random orientation of the molecules. Additional structural information can be retrieved if the molecules are aligned. Molecules can be impulsively aligned with femtosecond laser pulses, producing a transient alignment. The alignment persists only for a time on the order of a picosecond, so a pulsed electron gun is needed to record the diffraction patterns. In this manuscript, we describe the alignment process and show the changes in the diffraction pattern as …


Mega-Electron-Volt Ultrafast Electron Diffraction At Slac National Accelerator Laboratory, Stephen Weathersby, G. Brown, Martin Centurion, T. F. Chase, Ryan Coffee, Jeff Corbett, J. P. Eichner, J. C. Frisch, A. R. Fry, M. Gühr, Nick Hartmann, Carsten Hast, R. Hettel, R. K. Jobe, E. N. Jongewaard, J. R. Lewandowski, R. K. Li, A. M. Lindenberg, Igor Makasyuk, J. E. May, D. Mccormick, M. N. Nguyen, Alexander Reid, Xiaozhe Shen, K. Sokolowski-Tinten, Theodore Vecchione, Sharon Vetter, J. Wu, Jie Yang, H. A. Dürr, Xijie Wang Jan 2015

Mega-Electron-Volt Ultrafast Electron Diffraction At Slac National Accelerator Laboratory, Stephen Weathersby, G. Brown, Martin Centurion, T. F. Chase, Ryan Coffee, Jeff Corbett, J. P. Eichner, J. C. Frisch, A. R. Fry, M. Gühr, Nick Hartmann, Carsten Hast, R. Hettel, R. K. Jobe, E. N. Jongewaard, J. R. Lewandowski, R. K. Li, A. M. Lindenberg, Igor Makasyuk, J. E. May, D. Mccormick, M. N. Nguyen, Alexander Reid, Xiaozhe Shen, K. Sokolowski-Tinten, Theodore Vecchione, Sharon Vetter, J. Wu, Jie Yang, H. A. Dürr, Xijie Wang

Martin Centurion Publications

Ultrafast electron probes are powerful tools, complementary to x-ray free-electron lasers, used to study structural dynamics in material, chemical, and biological sciences. High brightness, relativistic electron beams with femtosecond pulse duration can resolve details of the dynamic processes on atomic time and length scales. SLAC National Accelerator Laboratory recently launched the Ultrafast Electron Diffraction (UED) and microscopy Initiative aiming at developing the next generation ultrafast electron scattering instruments. As the first stage of the Initiative, a mega-electron-volt (MeV) UED system has been constructed and commissioned to serve ultrafast science experiments and instrumentation development. The system operates at 120-Hz repetition rate …