Overview
Beam line 7-2 is a wiggler end station dedicated for x-ray absorption spectroscopy large scale rapid imaging and x-ray absorption spectroscopy (XANES, EXAFS) of biological, material science, and geological samples. A series of polycapillaries and pinholes can provide beam sizes from mm to ~ 35 x 35 microns. The energy range of the beam line optics covers 4.9-16 keV, with detection of fluorescent x-rays as low as Si. BL7-2 is equipped with a 7 element Vortex silicon drift detector and ionization chambers. Sample positions are controlled with submicron accuracy and has a stage motion range of ~1000 mm horizontally and ~300 mm vertically, ideal for obtaining elemental maps of many smaller samples or larger samples.
(After many years of service, the materials science scattering capability was moved from BL7-2 to BL17-2 which is currently in development/commissioning)
Main Scientific Disciplines:
Bioscience
Environmental Sciences
Geological Sciences
Materials Sciences
Status —
Beamline Parameters —
| Energy Range | Resolution ΔE/E | Spot Size | Flux | |
|---|---|---|---|---|
| Focused | 5000-16200 eV | 1 x 10-4 | 35 micron to 2mm | 5 x 1010 |
Optics —
| M0 Mirror | Monochromator |
|---|---|
| Vertical focusing, flat bent, 0.6 m, Si, Rh-coated | -cooled Si(111), ϕ = 0o, double-crystal Sagittal focusing |
Source —
Instrumentation —
| Detectors | ionization chambers, 7-element Vortex Silicon Drift Detector, CCD detector for µXRD, Visible CCD camera with fluorescence filters |
|---|---|
| Sample Positioning | Newport sample positioner |
| Other | Shutter and variable filters to protect detectors and alleviate sample beam damage.Ele |
Sample Environment —
| Standard | Ambient temperature and pressure, N2/He atmosphere |
|---|---|
| Flexible mounting frames | |
| Compatible with sample cartridges from multi-position sample wheel. | |
| Sample temperature: see above | |
| Sample size: up to 30 cm x 1 m |
Absorption —
| 46 μm Be, 15 μm C |
|---|
