Beam line 4-3 is a wiggler side-station dedicated for x-ray absorption spectroscopy and EXAFS measurements on biological, environmental, catalysis, and materials systems. This station enables tender x-ray measurement (S K-edge and up, i.e. 2.4-5 keV) in addition to hard x-rays ( up to 11 keV). It is setup with a He flight path from the beam line optics to the sample. The beam is collimated and unfocused to allow for high energy-resolution measurements on homogenous samples. BL4-3 is equipped with a 4-element solid-state silicon drift detector in addition to ionization chambers and PIPS/Lytle detectors. A LHe cryostream allows for low-temperature measurements. A motorized sample holder stage allows sequential measurement on multiple samples. Infrastructure for in-situ catalysis with mass-flow control and reactor cells have recently been added.
| Status | Open |
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| Supported Techniques | X-ray Absorption Spectroscopy |
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| Main Scientific Disciplines | Bioscience Catalysis Environmental Sciences Materials Sciences |
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| Beam Line Specifications | |||||||||||
Source20-pole, 2.0-Tesla Wiggler, 0.75 mrad, Side station
OpticsM0 mirror: vertically collimating, flat, bent, 1.0 m, bare Si, cutoff ~10.5 keV Monochromator: LN2 cooled, Si(111), ϕ = 0o & 90o, double-crystal, non-fixed exit slit Monochromator Crystal Glitch Library Crystal changes need to be scheduled and coordinated in advance with BL support staff Absorption127 micron Be |
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| Instrumentation | Detectors: Ionization chambers, PIPS, Lytle, Hitachi HTA 4-element solid-state Si drift detector, electron-yield detector Cryostat: LHe cryostream Other: He-purged sample box. He flow meters and oxygen content meter on sample space. Automated shutter to alleviate beam damage. Motorized multiple solid-sample holder. Gas cabinet, mass flow control, reactor cells for in-situ catalysis. |
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| Sample Environment | Ambient He atmosphere in gas tight sample box (room temperature) plastic sample compartment (for He cryostream) Sample temperature: 20-50 K (He cryostream) or Room temperature (no cryostat) Sample size: 5 X 20 mm Minimum Sample Requirement: 2-5 mM, 200 ul or 100 ppm, 2-5 mg at tender energies. 2 mM, 200 μl solutions or 10 ppm, 10 mg solids at higher energies. Automatic scan queueing available for multiple room temperature samples and/or multiple spots on cold samples. For catalysis: reactor cells. |
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| Data Acquisition and Analysis | WebXAS Data Collector, EXAFSPAK, SixPAK |
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| Beam Line Phone | 650-926-5243. On-site Users: Contact the Duty Operator at 9-926-4040 |
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| Beam Line Contact | |||||||||||
