Enhanced Functionality for Materials Analysis in the DTEM

The recent explosion in the use of pump-probe studies on the picosecond timescale to investigate structural and electronic phase transitions and the dynamics of chemical reactions has been based largely on laser-induced reactions coupled with laser interrogation techniques, or on laser induced reactions coupled with synchrotron radiation interrogation techniques. Much less attention has been given to approaches based on laser-induced (or electron-beam-induced) reactions coupled with electron interrogation methods, despite the fact that electron sources are brighter, and their interactions with matter stronger (thereby giving higher signal levels). The use of electrons as probes has great potential to study complex transient events not only because of the possible high temporal resolution using ultrafast electron diffraction (UED) but also the potential for high spatial resolution using dynamic transmission electron microscopy (DTEM). Taking this potential of electron interrogation methods and turning it into a routine nanoscale characterization technique requires several key aspects of the instrumentation used for electron microscopy/diffraction to be optimized. In this proposal, several approaches to instrument optimization for DTEM and UED (to be performed in the same instrument) will be addressed. The new instrumentation developments will be used to study the dynamics of strongly driven materials, aging and corrosion in structural materials, as well as the nanoscale structural properties of other materials systems. In addition to providing new instrument capabilities (the technology for which will be transferred to the DTEM at Lawrence Livermore National Laboratory (LLNL)) and fundamental insights into the dynamic properties of materials, the interaction between 3 universities (University of California-Davis, University of Illinois at Chicago and Arizona State University) and 2 national laboratories (LLNL and Sandia National Laboratory) will help train the next generation of students in areas of relevance to the stockpile stewardship