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Beam Line 7-3 X-ray Absorption Spectroscopy

Beamline 7-3 is a side-station on the 20-pole 2T wiggler beamline 7 dedicated for X-ray absorption spectroscopy and EXAFS measurements on dilute biological systems in the hard x-ray regime. 7-3 is equipped with a 30-element Ge solid-state detector in addition to ionization chambers and Lytle detectors. A dedicated liq-He cryostat allows for routine low temperature measurements. The unfocused beam provides lower flux and is ideal for samples especially susceptible to radiation damage, such as high-valent intermediates and other oxidized species. The beamline is equipped with beam attenuating filters and motorized shutters systems to minimize radiation damage.

BL7-3 Technical Specifications


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.