Training Workshop in use of Synchrotron Radiation and CCP13 Software for NonCrystalline Diffraction

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Training Workshop in use of Synchrotron Radiation
and CCP13 Software for Non-Crystalline
Diffraction / Fibre Diffraction

• 23rd-24th November 1999
• at
• Daresbury Laboratory

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Programme - Day 1
Tuesday 23rd November in Conference Room
4 115pm Meet in B-Block Foyer 130pm Welcome 1
.40pm - 2.30pm Introduction to Scattering and the
Synchrotron 230pm 300pm Tea/Coffee 300pm
500pm Data collection on beamline 8.2
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Programme - Day 2
Wednesday 24th November in Lab 19 1015am Meet
in B-Block Foyer 10.30am 1120am Data
Reduction Techniques 1120am
1140am Coffee/Tea 1140am 1230pm Basic Data
Analysis Software (XFIT, CORFUNC,
etc) 1230pm 200pm Lunch 200pm
300pm CCP13 software training in Lab 19 300pm
320pm Tea/Coffee 320pm 430pm CCP13
software training in Lab 19 430pm Close
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Synchrotron Studies

• Synchrotron Source.
• UK - SRS at Daresbury (2nd Generation)
• Elsewhere - ESRF, ALS, SPring-8, etc. (3rd
  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

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The SRS at Daresbury
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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.

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Scattering - WAXS(but also SAXS)

• Braggs Law

q
q
d
beamstop
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Small Angle Scattering

• Small angle scattering is used to study large
  structures, 10-10,000Å.
• Measurements are made in terms of q, the
  characteristic variable. (Biologists often use s
  where q2ps)
• 2q is the scattering angle, l is the wavelength
  of the radiation.
• 2.1 and 8.2 use 1.5Å x-rays 16.1 1.4Å, (6.2 will
  have variable l)
• 7.2 uses 1.3Å and 1.5Å and 14.1 1.2 or 1.5Å for
  fibre diffraction

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Length Scales - Where do SAXS WAXS fit in?

• SAXS is usually considered to include angles ? lt
  1
• in practice ? lt 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

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Homopolymer Morphology
Visible Light
WAXS (Crystallography)
SAXS
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Back to Front
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Beamline Layout
Monochromator
Mirror
Slit set 2
Slit set 3
Slit set 1
Slit set 4
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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.
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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 ScatteringNruka, 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

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Fibre Diffraction

• Fibre Diffraction Methods, ACS Symposium Series,
  American Chemical Society, Washington DC, 1980.
  Eds. A.D. French K.H. Gardner
• Diffraction of X-Rays by Chain Molecules, B.K.
  Vainshtein, Elsevier Publishing Company, 1966

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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(r1-r2) 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.

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Fourier Transforms
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Contact Points

• http//srs.dl.ac.uk/index.htm
• http//www.srs.dl.ac.uk/ncd/
• http//www.srs.dl.ac.uk/ncd/station21/index.html
• http//www.srs.dl.ac.uk/ncd/station82/index.html
• http//www.srs.dl.ac.uk/ncd/station161/index.html
• http//www.dl.ac.uk/SRS/PX/7_2_manual/man.html
• http//www.dl.ac.uk/SRS/CCP13/main.html
• E-mail addresses
• http//www.clrc.ac.uk/People/PPR