Search

Page • Understanding complex chemical physics systems often involves correlations among properties, making multidimensional diagnostics a natural tool. The CRF invents and employs imaging methods to probe such correlations: from ion imaging, which directly measures correlated angular and velocity distributions in single molecular collisions or photodissociation to four-dimensional imaging of chemical processes...

Page • CRF researchers have made breakthroughs that support chemical physics research in areas such as non-linear spectroscopy, ion imaging, 3-dimensional optical imaging, multiplexed photoionization/photoelectron spectroscopy, and x-ray absorption and scattering. Some of the resulting capabilities are described in the Experimental Capabilities section. Many of these breakthroughs are based in fundamental research...

Page • The CRF pursues collaborations with industry, academia, and government to conduct leading-edge research that helps the U.S. Department of Energy meet national goals, one of which is to help industry resolve challenging technical issues that, in turn, can impact U.S. economic competitiveness. Sponsors Several U.S. Department of Energy program areas...

Page • Fuel spray injection will be a key element for enabling high-efficiency, low-emission engines of the future. Understanding the spray combustion process is critical, however, investigating engine combustion processes is challenging due to factors affecting the in-cylinder environment where mixing with fuel sprays occurs. The temperature, pressure, density, and composition of...

Page • Stochastic models are useful in chemical modeling at intermediate scales. Our work in this area includes the development of numerical methods for dealing with stiffness in the chemical Langevin equation and in kinetic Monte Carlo models. Stiffness in Stochastic Chemical Models We have developed time integration strategies that target efficient...

Page • Although a powerful technique, analyzing molecules based on mass does not always enable us to identify specific molecular structures. Photoionization spectroscopy can yield isomer-specific information from mass spectrometry, but as the molecules grow larger in the chemistry leading to soot formation, for example, the photoionization spectra are no longer diagnostic....

Page • Project/Program Description We use electronic structure methods, master equations, and molecular dynamics to explore and interpret transformations at the atomic scale in molecular systems. Impact Statement Figure 1 The potential energy surface of the acetylene + acetylene reaction. We are interested in chemical reactions and structural changes in molecules initiated...

Page • Technical Details We investigate electronic excited state dynamics in gas phase molecules using ultrafast core-to-valence transient absorption spectroscopy. This technique combines element specificity with sensitivity to local bonding environment and spin state. In this experiment, an ultraviolet pump pulse electronically excites the molecule of interest, and an extreme ultraviolet (XUV)...

Page • Technical Details We investigate vibrational dynamics in electronic ground and excited states of gas phase and condensed phase systems using ultrafast infrared transient absorption spectroscopy. These experiments may utilize ultraviolet or narrowband infrared pump pulses to initiate the dynamics on an electronic excited or the electronic ground state of a...

Page • Figure 1 Our work in uncertainty quantification (UQ) includes a range of research activities having to do with the quantification of uncertainty in computational model inputs and outputs. The work involves a focus on the development of numerical methods and open source software for statistical learning from data, forward propagation...

Page • Uncertainty Quantification Toolkit Overview The Uncertainty Quantification Toolkit (UQTk) is a lightweight open source C++ library, (available at http://www.sandia.gov/UQToolkit) primarily offering tools for the propagation of uncertain inputs and parameters through a computational model. Figure 1 UQTk allows other researchers to apply our algorithm UQ research to many other applications. It is well suited...

Page • We invite you to take a virtual tour of the CRF! Interested in visiting the Sandia California site in person? Visitors and potential collaborators are encouraged to explore the CRF’s research programs online before contacting the technical area manager to arrange a meeting. Click on image below for a more...