Experimental Station 4-2 | Stanford Synchrotron Radiation Lightsource

BL4-2 is a small-angle scattering station dedicated to structural biology studies primarily on non-crystalline systems. The 20-pole wiggler in combination with the multilayer monochromator provides high brilliance x-ray beam for time-resolved studies down to milliseconds. This facility covers the range of characteristic length scale of a few Angstroms to a few micrometers by the combined use of a pin-hole geometry camera, which can be automatically configured to have one of 7 sample-to-detector distances, and a separate ultra small angle scattering setup. A Rayonix MX225-HE detector is our primary detector. A Dectris Pilatus 300K pixel array detector system is used for fast time-resolved studies. The facility provides a large selection of sample handling devices, such as stopped-flow rapid mixers, capillary flow cells and automated sample changer for solution scattering.

Status

Open

Type

X-ray

Source

20-pole, 2.0-Tesla Wiggler ID End Station

Energy Range

6000-18000 eV

% Time General Use

100%

Supported Techniques

Biological Small-angle X-ray Scattering (BioSAXS)

Fiber diffraction

Lipid membrane diffraction

Small-angle single crystal diffraction

Main Scientific Disciplines

Bioscience

Beam Line Specifications

	Energy Range	Resolution ΔE/E	Spot Size	Flux	Angular Acceptance
Focused (Crystal)	6000-18000 eV	~5 x 10^-4	0.2 x 1mm	N/A	< 1.0 mrad
Focused (Multilayers)	8000-12000 eV	~3 x 10^-2	0.2 x 1mm	N/A	< 1.0 mrad

Optics

Bent cylinder mirror, silicon, Rh-coated
Radii: 15.4m vertical (adjustable) x 57mm horizontal
Mean angle of incidence: 3.8mrad
Cut off energy: 17.5keV
Magnification: 1.0

Monochromator

Parallel crystal geometry
Si(111), Mo/B4C multilayers
Upward reflecting
Liquid nitrogen-cooled monochromator (same as other insertion device hard x-ray stations)

Monochromator Crystal Glitch Library

Crystal changes need to be scheduled and coordinated in advance with BL support staff.

Detector

N/A

Sample Environment

N/A

Absorption

N/A

Instrumentation

Please refer to http://ssrl.slac.stanford.edu/~saxs

Data Acquisition and Analysis

Data acquisition: Blu-ice, HiPic
see: http://www-ssrl.slac.stanford.edu/~saxs/daq/daq.htm

Data analysis: SasTool, fit2D
see: http://www-ssrl.slac.stanford.edu/~saxs/daq/daq.htm

X-ray Data Booklet

Additional Notes

Angular Range

Distance(m)	Typical Q (2ps) Range(Å…-1)
0.25	0.045 - 3.6
0.45	0.024 - 2.2
0.65	0.017 - 1.6
1.10	0.010 - 1.0
1.65	0.0068 - 0.67
2.40	0.0045 - 0.46
3.40	0.0034 - 0.33
E=11keV, 4mm circular beam stop assumed

Beam Line Staff

Thomas Weiss

Tsutomu Matsui

Ping Liu

Beam Line Phone

650-926-5242. On-site Users: Contact the Duty Operator at 9-926-4040

Engineering Notes

Resource Links

Resource Documents