Training Workshop in use of Synchrotron Radiation and CCP13 Software for Non-Crystalline Diffraction / Fibre Diffraction 23 rd -24 th November 1999 at Daresbury Laboratory

Programme - Day 1 Tuesday 23rd November in Conference Room 4 1:15pmMeet in B-Block Foyer 1:30pmWelcome 1.40pm pmIntroduction to Scattering and the Synchrotron 2:30pm – 3:00pmTea/Coffee 3:00pm – 5:00pmData collection on beamline 8.2

Programme - Day 2 Wednesday 24th November in Lab 19 10:15amMeet in B-Block Foyer 10.30am – 11:20amData Reduction Techniques 11:20am – 11:40amCoffee/Tea 11:40am – 12:30pmBasic Data Analysis Software (XFIT, CORFUNC, etc) 12:30pm – 2:00pmLunch 2:00pm – 3:00pmCCP13 software training in Lab 19 3:00pm – 3:20pmTea/Coffee 3:20pm – 4:30pmCCP13 software training in Lab 19 4:30pmClose

Synchrotron Studies Synchrotron Source.  UK - SRS at Daresbury (2 nd Generation)  Elsewhere - ESRF, ALS, SPring-8, etc. (3 rd Generation)  Future - Diamond Daresbury Beamlines for NCD/Fibre Diffraction.  16.1, 2.1, 8.2, 7.2 (6.2, 14.1) Why?  Flux  Time Resolution - Dynamic studies are possible  Support Facilities

The SRS at Daresbury

Synchrotron Radiation Accelerated electrons give out a whole spectrum of radiation from Infra red to Hard x-rays. Lab source, acceleration is when the electrons slam into the copper anode: Bremsstrahlung. Synchrotrons use bending magnets, Wigglers and Undulators to bend the electrons. By bending the electrons you cause them to accelerate towards the orbit centre. The tighter the bend, the more acceleration, the higher the flux. The SRS operates at 200mA and 2GeV. acceleration

Scattering - WAXS (but also SAXS) Bragg’s Law d   Increasing q Increasing d beamstop

Small Angle Scattering Small angle scattering is used to study large structures,   Å. Measurements are made in terms of q, the characteristic variable. (Biologists often use s where q=2  s) 2  is the scattering angle,  is the wavelength of the radiation. 2.1 and 8.2 use 1.5Å x-rays Å, (6.2 will have variable  7.2 uses 1.3Å and 1.5Å and or 1.5Å for fibre diffraction 22 kiki ksks q

Length Scales - Where do SAXS & WAXS fit in? SAXS is usually considered to include angles  < 1°  in practice  0.1 ° SAXS/WAXS experiments collect standard XRD with SAXS to give small scale resolution For solution scattering (e.g. DNA and proteins) you are limited to about 10Å resolution WAXSSAXS USAXS RayleighLorentzFraunhoffer SEM TEMOptical Microscope AFM/STM 1Å = 10-10m Å 1  m = 10 4 Å

Homopolymer Morphology L WAXS (Crystallography)SAXS Visible Light

Back to Front F.T. F.T.

Beamline Layout Monochromator Mirror Slit set 1 Slit set 2 Slit set 3 Slit set 4

Detectors * Depending on Local Count rates. Limited by the speed of the readout electronics. † Saturation point of the readout instrumentation.  Saturation point of the CCD.

Small Angle Scattering (SAXS) O. Glatter and O. Kratky “Small Angle X-Ray Scattering” (Out of Print) A. Guinier, G. Fournet, C.B. Walker, K.L. Yudowitch “Small Angle Scattering of X-Rays” (Out of Print) L.A. Feigun and D.I. Svergun “Structure Analysis by Small Angle X-Ray & Neutron Scattering”Nruka, Moscow, 1986, English Translation Ed. G.W. Taylor, Plenum, New York, 1987 H. Brumberger “Modern Aspects of Small Angle Scattering”, NATO ASI Series, Kluver Academic Press 1993 P. Linder, Th Zemb “Neutron, Xray & Light Scattering, Introduction to an Investigative tool for Colloidal and Polymeric Systems”

Fibre Diffraction Fibre Diffraction Methods, ACS Symposium Series, American Chemical Society, Washington DC, Eds. A.D. French & K.H. Gardner Diffraction of X-Rays by Chain Molecules, B.K. Vainshtein, Elsevier Publishing Company, 1966

Scattering Theory (Simplified) Scattering arises from induced dipoles in atomic electrons. As the scatterers are approximately the same size as the incident wavelength you get a decay in your scattered signal with angle. The general formula is This can be simplified by integrating over all r=(r 1 -r 2 ) that are equal, then by integrating over all the different r. This first step gives the auto-correlation function This is the well known Paterson function. Putting this back into the general formula gives This is a Fourier Transform and as such there exists a reciprocal relationship between r and q. For large r you must measure your scattering at low q.

Fourier Transforms

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