Synchrotron radiation needs for molecular environmental science



Synchrotron facilities provide exceptionally high brightness, tunable X-ray sources that make possible a range of novel techniques allowing molecular-scale and sometimes time-resolved characterization of diverse types of materials. Focusing the X-ray beam to nanometer to micrometer sizes enables spectroscopic and scattering measurements at high spatial resolution, thereby allowing study of complex, heterogeneous environmental samples in which elements of interest are commonly dilute. Such molecular-scale characterization provides the basis for understanding fundamental reaction mechanisms, chemical speciation of trace and major elements, contaminant mobility/bioavailability, and element cycling in the hydrosphere.

It is no surprise therefore that synchrotron radiation techniques, such as X-ray absorption spectroscopy and scattering, have become core techniques in the fields of molecular environmental science (MES) and low-temperature geochemistry (LTG). The synchrotron user group EnviroSync organized a workshop in Rockville, Md., to assess current capabilities at U.S. synchrotron facilities and future needs for these communities. Sponsorship was provided by the U.S. Department of Energy's Office of Basic Energy Sciences and Office of Biological and Environmental Remediation and by the U.S. National Science Foundation's Earth Sciences Directorate. The 50+ participants included academic and national laboratory researchers, beam line scientists, instrument designers, and facility directors and representatives. Program managers from funding agencies provided perspectives from Washington.