Promising X-ray fluorescence tests for superconducting tunneljunction detector [electronic resource]
Scientists in the Physical Biosciences Division of the Ernest Orlando Berkeley National Laboratory (Berkeley Lab) studying transition metals in proteins with fluorescence-detected L-edge absorption spectroscopy have found the measurements to be extremely challenging. The difficulty is that the metal...
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| Online Access: |
Online Access |
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| Format: | Government Document Electronic eBook |
| Language: | English |
| Published: |
Washington, D.C. : Oak Ridge, Tenn. :
United States. Department of Energy. ; distributed by the Office of Scientific and Technical Information, U.S. Department of Energy,
2001.
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| Subjects: |
| Summary: | Scientists in the Physical Biosciences Division of the Ernest Orlando Berkeley National Laboratory (Berkeley Lab) studying transition metals in proteins with fluorescence-detected L-edge absorption spectroscopy have found the measurements to be extremely challenging. The difficulty is that the metal centers are present in very dilute concentrations so that their weak fluorescence is often obscured by strong background signals carbon and oxygen. To solve this problem, the Berkeley group has been working with researchers from the Advanced Detector Group at the Lawrence Livermore National Laboratory on an energy-dispersive superconducting tunnel junction x-ray detector. These devices in principle have the energy resolution needed to reveal the metal signal. The most recent results with the latest version of the detector on Beamline 4.0.1-2 at the Advanced Light Source (ALS) illustrate the promise of the cryogenic detector strategy not only for this application but also for spectroscopy of other types of dilute samples. Transition-metal complexes are key elements in many biologically important processes that are catalyzed by proteins (enzymes), photosynthesis being a prime example. The changes in that occur in electronic structure throughout a catalytic cycle are the subject of much research aimed at understanding the mechanisms of these processes. L-edge x-ray spectroscopy offers several advantages relative to the more common K-edge techniques, since it involves allowed transitions to the d-orbitals associated with metal-ligand bonding. It also has a rich multiplet structure interpretable by theory and higher spectral resolution. Superconducting X-Ray Detectors Superconducting Tunneljunctions. |
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| Item Description: | Published through SciTech Connect. 05/15/2001. "lbnl--48615" ": YN0100000" Synchrotron Radiation News 14 2 FT. Friedrich, Stephan; Robinson, Arthur L. Ernest Orlando Lawrence Berkeley NationalLaboratory, Berkeley, CA (US) |