scholarly journals Final Report of the International Project for the Calibration of Absolute Intensities in Small-Angle X-ray Scattering

1978 ◽  
Vol 11 (3) ◽  
pp. 196-205 ◽  
Author(s):  
Keyword(s):  
Small Angle ◽  
Absolute Intensity ◽  
Final Report ◽  
X Ray ◽  
X Ray Scattering ◽  
Calibration Methods ◽  
The Absolute ◽  
Calibration Techniques ◽  
Intensity Calibration ◽  
Ray Scattering

An international intercomparison project was performed to test the reproducibility and the comparative accuracy of the various absolute intensity calibration techniques in current use in small-angle X-ray scattering with the participation of fifteen investigators from eight different laboratories in six countries. In the project, the absolute differential X-ray scattering cross sections of standard samples of glassy carbon and polystyrene were calibrated using five different calibration techniques and two different X-ray wavelengths. The results have been intercompared with a variety of statistical techniques. It is concluded that angularly dependent errors associated with determining the zero of angle, dead-time corrections, collimation corrections, and insufficiently close data point spacing are more important in accounting for discrepancies between laboratories than are differences in the absolute intensity calibration methods themselves.

Performance on absolute scattering intensity calibration and protein molecular weight determination at BL16B1, a dedicated SAXS beamline at SSRF

2017 ◽  
Vol 24 (2) ◽  
pp. 509-520 ◽  
Author(s):  
Jianrong Zeng ◽  
Fenggang Bian ◽  
Jie Wang ◽  
Xiuhong Li ◽  
Yuzhu Wang ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Small Angle ◽  
Absolute Intensity ◽  
Molecular Weight Determination ◽  
X Ray ◽  
X Ray Scattering ◽  
Saxs Intensity ◽  
The Absolute ◽  
Intensity Calibration ◽  
Ray Scattering

The optical system and end-station of bending-magnet beamline BL16B1, dedicated to small-angle X-ray scattering (SAXS) at the Shanghai Synchrotron Radiation Facility, is described. Constructed in 2009 and upgraded in 2013, this beamline has been open to users since May 2009 and supports methodologies including SAXS, wide-angle X-ray scattering (WAXS), simultaneous SAXS/WAXS, grazing-incidence small-angle X-ray scattering (GISAXS) and anomalous small-angle X-ray scattering (ASAXS). Considering that an increasing necessity for absolute calibration of SAXS intensity has been recognized in in-depth investigations, SAXS intensity is re-stated according to the extent of data processing, and the absolute intensity is suggested to be a unified presentation of SAXS data in this article. Theory with a practical procedure for absolute intensity calibration is established based on BL16B1, using glass carbon and water as primary and secondary standards, respectively. The calibration procedure can be completed in minutes and shows good reliability under different conditions. An empirical line of scale factor estimation is also established for any specific SAXS setup at the beamline. Beamline performance on molecular weight (MW) determination is provided as a straightforward application and verification of the absolute intensity calibration. Results show good accuracy with a deviation of less than 10% compared with the known value, which is also the best attainable accuracy in recent studies using SAXS to measure protein MW. Fast MW measurement following the demonstrated method also enables an instant check or pre-diagnosis of the SAXS performance to improve the data acquisition.

scholarly journals NIST Standard Reference Material 3600: Absolute Intensity Calibration Standard for Small-Angle X-ray Scattering

2017 ◽  
Vol 50 (2) ◽  
pp. 462-474 ◽  
Author(s):  
Andrew J. Allen ◽  
Fan Zhang ◽  
R. Joseph Kline ◽  
William F. Guthrie ◽  
Jan Ilavsky
Keyword(s):  
Reference Material ◽  
Small Angle ◽  
Standard Reference Material ◽  
Absolute Intensity ◽  
Calibration Standard ◽  
X Ray ◽  
X Ray Scattering ◽  
Nist Standard Reference Material ◽  
Intensity Calibration ◽  
Ray Scattering

The certification of a new standard reference material for small-angle scattering [NIST Standard Reference Material (SRM) 3600: Absolute Intensity Calibration Standard for Small-Angle X-ray Scattering (SAXS)], based on glassy carbon, is presented. Creation of this SRM relies on the intrinsic primary calibration capabilities of the ultra-small-angle X-ray scattering technique. This article describes how the intensity calibration has been achieved and validated in the certifiedQrange,Q= 0.008–0.25 Å−1, together with the purpose, use and availability of the SRM. The intensity calibration afforded by this robust and stable SRM should be applicable universally to all SAXS instruments that employ a transmission measurement geometry, working with a wide range of X-ray energies or wavelengths. The validation of the SRM SAXS intensity calibration using small-angle neutron scattering (SANS) is discussed, together with the prospects for including SANS in a future renewal certification.

scholarly journals Absolute intensity calibration for carbon-edge soft X-ray scattering

2020 ◽  
Vol 27 (6) ◽  
pp. 1601-1608
Author(s):  
Thomas Ferron ◽  
Devin Grabner ◽  
Terry McAfee ◽  
Brian Collins
Keyword(s):  
Small Angle ◽  
Absolute Intensity ◽  
Small Angle Scattering ◽  
Interfacial Structure ◽  
Thin Polymer Film ◽  
X Ray ◽  
X Ray Scattering ◽  
Angle Scattering ◽  
Intensity Calibration ◽  
Ray Scattering

Resonant soft X-ray scattering (RSOXS) has become a premier probe to study complex three-dimensional nanostructures in soft matter through combining the robust structural characterization of small-angle scattering with the chemical sensitivity of spectroscopy. This technique borrows many of its analysis methods from alternative small-angle scattering measurements that utilize contrast variation, but thus far RSOXS has been unable to reliably achieve an absolute scattering intensity required for quantitative analysis of domain compositions, volume fraction, or interfacial structure. Here, a novel technique to calibrate RSOXS to an absolute intensity at the carbon absorption edge is introduced. It is shown that the X-ray fluorescence from a thin polymer film can be utilized as an angle-independent scattering standard. Verification of absolute intensity is then accomplished through measuring the Flory–Huggins interaction parameter in a phase-mixed polymer melt. The necessary steps for users to reproduce this intensity calibration in their own experiments to improve the scientific output from RSOXS measurements are discussed.

scholarly journals Phase densities and lamellar morphologies of semicrystalline polyethylenesviaabsolute small-angle X-ray scattering measurements

2015 ◽  
Vol 48 (5) ◽  
pp. 1498-1506 ◽  
Author(s):  
Monika Basiura-Cembala ◽  
Kurt Erlacher ◽  
Jan Skov Pedersen ◽  
Bart Goderis
Keyword(s):  
Amorphous Phase ◽  
Small Angle ◽  
Volume Fraction ◽  
Distribution Functions ◽  
X Ray Diffraction ◽  
X Ray ◽  
X Ray Scattering ◽  
Model Independent ◽  
The Absolute ◽  
Ray Scattering

With the crystalline volume fraction from small-angle X-ray scattering (SAXS) and the density of the crystalline phase from wide-angle X-ray diffraction, the amorphous phase density of two representative polyethylenes was calculated as a function of temperature using the absolute total SAXS scattering power or invariant. The density of the amorphous phase in semicrystalline polyethylene is crystallinity independent and is lower than melt-extrapolated values reported in the literature. Model-independent SAXS-based crystallinity values can be calculated with the aid of the densities of the crystalline and amorphous phase and the absolute SAXS invariant. Such model-independent crystallinity values can be used in SAXS curve-shape analysis procedures to obtain the average thickness of the crystalline and amorphous layers also in the case of non-ideal lamellar semicrystalline polymer morphologies for which the number-average long period cannot be retrieved from the maxima in correlation functions or interface distribution functions.

Sign in / Sign up

Export Citation Format

Share Document