BL1-4 is used primarily for Small-Angle X-ray Scattering (SAXS) and also some Wide-Angle X-ray Scattering (WAXS). The user community is active in Materials Science, Environmental Science, Nano-scale Development, Colloidal Science and some Medical fields.
BL1-4 hosts a range of available sample environments, detailed below, to cater for a wide range of sample materials in either solid or liquid state. The beamline can be configured for samples to be probed in either transmission (TRSAXS) or reflection (GISAXS) geometries. For a guide to running experiments at the beamline, see the BL1-4 Cheat Sheet.
| Status | Open |
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| Type | X-ray |
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| Source | 1.3 Tesla Bend Magnet |
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| Energy Range | 8333 eV |
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| % Time General Use | 100% |
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| Supported Techniques | |||||||||||||
| Main Scientific Disciplines | |||||||||||||
| Beam Line Specifications | |||||||||||||
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| Optics | Three-jaw beam defining slit (no fourth jaw, to allow passage of radiation fan to BL1-5) M0 mirror: SiO2 block, Pt coated, intercepts beam at 3.7 mrad incident, cutoff ~12 keV, bent to focus beam in the vertical plane. In He cooled environment |
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| Monochromator | Side reflecting single-bounce Si [111] crystal with 7.5° offcut planes. The crystal is bent, both to focus beam in the horizontal plane and increase flux (at partial expense of monochromaticity). In same He cooled environment as mirror M0 |
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| Detector | Rayonix165 CCD detector. 16 bit dynamic range. Active area of 165 mm diameter contains 4096 x 4096 15 µm square pixels (runs in standard mode of 2x2 binning of effectively 2048 x 2048 pixels) with 2.7 magnification fibre-optic taper giving effective pixel size of 80 µm in standard mode. Detector is He cooled to -80 °C to provide dark current of 13 e-/pixel in standard mode. |
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| Sample Environment | Oven. Incorporates in-house sample holders. Available temperatures from ambient to ~400°C, ±2 °C, but has no active cooling mechanism. Can incorporate titration-adapted sample holders in-situ. Multi-sample capillary holder. Drivable in X and Y; holds 24 capillaries of 1.5 mm diameter or smaller. Available temperatures from: 10 °C < T < 80 °C ±1 °C over all 24 sample positions. Huber 410 Goniometer. Drivable in X, Y and Θ (smallest stepsize 0.09°), used for GISAXS. Does not have temperature controlled environment at this time. Tensile tester. Tensile strain (asymmetric drive) can be applied to dumbbell samples of approx 15 mm x 5 mm dimensions in situ. Strain rate is controllable, but there is no transducer to measure stress. Tensile tester also has oven-enclosed environment controllable from ambient to 100 °C, ±1°C. Multi-purpose X-Y positioner. Drivable 240 mm in X; 200 mm in Y. Can hold solid samples independently, yet is primarily designed as support and positioning device for all sample environments listed above (except the tensile tester). Can also be adapted to hold and position sample environments brought by the user (e.g. to date it has been adapted for an electrochemical cell; humidity chamber; multi-sample oven, from various experimental groups; etc). If you have your own sample environment you wish to bring to the beamline, contact John Pople to arrange to integrate it optimally on the beamline. |
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| Absorption | N/A |
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| Instrumentation | Instrumentation is best detailed in terms of detector (above); sample enviroments (below) and the q ranges of the different experimental configurations available: Lowest-q SAXS config: 0.03 nm-1 < q < 0.4 nm-1
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| Data Acquisition and Analysis | Data Acquisition: Uses SPEC running on a RedHat Linux OS control computer BL14LX. BL14LX governs all experimental control: the shutter, the slits, the ion chambers, all sample motors and temperature control; and (indirectly) the detector and data storage. BL14LX has the IP address 192.1.14.10 on the broader network and 192.2.14.1 on the Local Area Network (LAN) with the detector interface computer MARCCD (IP address 192.2.14.2; also on a RedHat Linux OS). Data is collected by SPEC commands on the BL14LX computer interfacing with the MARCCD computer over the LAN. For questions and issues related to SPEC, contact beam line staff or send an email to Data is stored on the remotely accessible file server specfs.slac.stanford.edu. Experimenters can utilize secure shell software, such as the freeware WinSCP to access their partitions on this server. Login protocol requires username expressed as SSRL\b_username and the same password that was used at SSRL for the b_username account. Data Reduction: Uses in-house macros running in Image Pro Plus software running on a Windows XP PC (GUEVARA). The macros collapse two-dimensional X-ray images to one-dimensional profiles from which meaningful physical parameters can be extracted; and correct for necessary masking. Macros exist to collapse TRSAXS images radially (producing plots of I(q) vs q) and azimuthally (producing plots of I(Φ) vs Φ) and to collapse GISAXS images rectangularly to produce plots of I(qxy) vs qxy and I(qz) vs qz. Data is output in both ascii files and excel spreadsheets For more information on either Data Acquisition or Reduction, see the BL1-4 cheat sheet. Data Analysis: A stand-alone data analysis station is under development (Apr 2012) and will consist of a Windows XP based PC (ATHENA) running the small angle scattering analysis tool Irena. A duplicate copy of the Data Reduction software and macros is also available on this PC. This data analysis station enables experimenters to process data distinctly from beamline operation; allowing more than one experimental group to operate at one time. |
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| Additional Notes | Selected Science Highlights: • January 2011: Science Snapshot: Nickel Nanocubes |
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| Beam Line Staff | |||||||||||||
| Beam Line Phone | 650-926-5214 . On-site Users: Contact the Duty Operator at 4040 |
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| Engineering Notes | |||||||||||||
| Resource Links | |||||||||||||
| Resource Documents | |||||||||||||
