Beam Line 4-3 X-ray Absorption Spectroscopy
Beamline 4-3 is a wiggler side-station beamline dedicated for X-ray absorption spectroscopy and EXAFS measurements on biological and environmental systems. This station enables tender X-ray measurement (S K-edge and up) and is setup with a He flight path from the beamline optics to the sample. The beam is collimated and unfocused to allow for high energy-resolution measurements on homogenous samples. 4-3 is equipped with a four-element solid-state silicon drift detector in addition to ionization chambers and Lytle detectors. A liquid He cryostream allows for low-temperature measurements. A motorized sample holder stage allows sequential measurement on multiple samples without sample changeover delays.
The SSRL SMB group is directly responsible for the maintenance and operation of the biological spectroscopy beamlines. User support is provided at the technical, engineering and scientific level of data acquisition and analysis by experienced staff personnel. See more.
The SMB group maintains and operates standard and specialized in-hutch instrumentation for a variety of research programs. These include; cryostats for low-temperature measurements, detector systems serving dilute and concentrated samples and specialized instrumentation for tender-energy and single-crystal XAS measurements. Experimental details about beamlines and information about their specific capabilities are listed under each beamlines technical page.
An interactive interface of the monochromotor crystal glitch library can be found here
The data collection softwares used on the spectroscopy beamlines include XASCollect and XASSCAN. Beamline computers are also equipped with the data analysis softwares EXAFSPAK and SixPACK.
The next steps after successful data measurement at the experimental station are data reduction, analysis and simulation. SSRL staff provides training and support for in-house data analysis software for preliminary data-analysis and the SMB group organizes annual Summer Schools for training in advanced experimental data analysis. In addition, several web-based resources are available for additional and specialized information.
The research conducted at the bio-spectroscopy beamlines follows the mission of NIH and DOE-BER and is aimed at elucidating the geometric and electronic structure of metalloprotein and cofactor active sites and biomimetic model complexes in order to shed light on the mechanistic aspects of relevant biological systems. High-impact publications from the bio-spectroscopy beamlines are routinely highlighted by SSRL. See more.