Our objective is to ensure that the NIST beamlines U7A, X23A2, and X24A, located at the National Synchrotron Light Source (NSLS) at Brookhaven National Laboratory, operate efficiently, effectively, and safely to enable customers to conduct their experiments. The Department of Energy (DOE) is our partner in this endeavor. One of our main goals is to meet DOE's requirement that 25% of the beam time for each beamline is reserved for general users.
Impact and Customers:
Over the past 15 years, we have established the following measurement capabilities at three beamlines at the NSLS: (1) near-edge X-ray absorption fine structure spectroscopy (NEXAFS) at beamline U7A; (2) extended X-ray absorption fine structure spectroscopy (EXAFS) at beamline X23A2; and, more recently, X-ray photoelectron spectroscopy (XPS) at beamline X24A. Although these beamlines operate 24 hours per day, seven days per week, the demand for beamtime far exceeds the time available. We continuously strive to maximize beamline accessibility and ease of operation for beamline users by developing new and improved operating practices. Further, we provide service to the synchrotron community by working with NSLS and DOE to optimize beamline operations and transfer our best practices to other beamlines at the NSLS. Members of our team have chaired the NSLS Users' Executive Committee and have served on its Science Advisory Committee. Our team has served on DOE synchrotron proposal review panels at the NSLS, at the Advanced Photon Source, and at the Canadian Light Source.
EXAFS hutch before modifications
Reconfigured EXAFS hutch and components
Major modifications were made to the EXAFS hutch at beamline X23A2 to allow full utilization of the newly commissioned sample stage to accommodate our state-of-the-art low temperature closed cycle helium refrigeration system, which should be commissioned in FY10. This modification provides additional room to
all other experiments as well.
The EXAFS hutch also has new ion chambers and a new optical rail for maintaining alignment of the detector systems.
Large beam from U7A wobble mirror
Major vacuum modifications of beamline U7A to allow the installation of a new parallel process, full-field imaging NEXAFS endstation were completed. The imaging endstation makes full use of the wobble mirror system which can deliver a 20 mm x 20 mm beam at the sample position of the new imaging NEXAFS endstation.
Integration of the imaging NEXAFS endstation into the U7A beamline allows pass-through of the monochromatic beam to the downstream endstations by raising the wobble mirror (in situ), enabling rapid switching between endstations to optimize beamtime usage.
The imaging NEXAFS endstation includes a sample load lock and computerized sample manipulator for a bar holding up to 10 samples. The same sample bar and handling hardware is also used at our other NEXAFS and XPS endstations, thus enabling rapid sample exchange between endstations.