<html>
<body>
Dear Colleagues,<br><br>
The G.R. Harrison Spectroscopy Laboratory and the Department of
Electrical Engineering and Computer Science would like to invite you to
the next seminar in our series on Modern Optics and
Spectroscopy.<br><br>
Date &
Time:<x-tab> </x-tab><x-tab> </x-tab>Tuesday,
November 2, 12 noon - 1 PM<br>
Location:<x-tab> </x-tab><x-tab> </x-tab>Grier
Room (34-401)<br>
Speaker:<x-tab> </x-tab><x-tab> </x-tab><b>Christoph
Rose-Petruck</b>, Brown University<br>
Title:
<x-tab> </x-tab><x-tab> </x-tab><i>Ultrafast
(XAFS) measurement of solvated transition metal complexes<br><br>
</i>Refreshments will be served following the talk.<br><br>
Abstract<br>
<b>Christoph Rose-Petruck</b>, Brown University<br>
<i>Ultrafast (XAFS) measurement of solvated transition metal
complexes<br>
</i> Ultrafast high-intensity laser pulses
incident upon condensed matter targets can generate high-density plasmas
that emit x-ray pulses with sub-picosecond temporal structure,
significant spatial coherence, and high brightness. Such a laser-driven
plasma x-ray source operating at kilohertz repetition rates has been
developed in our laboratory. Details of the experimental apparatus,
including the x-ray optics are presented. Essential performance features
related to ultrafast time-resolved x-ray absorption fine structure (XAFS)
spectroscopy are discussed.<br>
Structural parameters of solvated
Fe(CO)<sub>5</sub> were measured by XAFS spectroscopy using our ultrafast
laser driven x-ray source. The spectra are compared to XAFS spectra
measured with a micro-focus as well as a synchrotron x-ray source.
Furthermore, the data are compared to theoretical XAFS spectra based on
Density Functional Theory (DFT) calculations of the solvated complex. All
experimental and theoretical structure data were found to be in close
agreement.<br>
Laser-pump XAFS-probe measurements of
Fe(CO)<sub>6</sub><sup>4-</sup> in water have been performed at various
pump-probe delay times before and after UV-photoexcitation of the
complex. The experimental results are discussed and measured picosecond
time-resolved XAFS spectra are presented.<br><br>
<br>
<x-sigsep><p></x-sigsep>
Vinnie Russo * vrusso@mit.edu * Office Manager<br>
MIT; G.R. Harrison Spectroscopy Laboratory<br>
77 Mass. Ave., 6-014 * Cambridge, MA 02139<br>
(v) 617-253-9774 * (f) 617-253-4513 </body>
</html>