SLIDE 1
A “peak” inside water
Alan K Soper FRS, ISIS Facility, STFC Rutherford Appleton Laboratory, UK
- Prof. Sir John Enderby
P r
- f
. P e t e r E g e l s t a f f
A peak inside water Prof. Sir John Enderby P r o f . P e t - - PowerPoint PPT Presentation
A peak inside water Prof. Sir John Enderby P r o f . P e t - - PowerPoint PPT Presentation
A peak inside water Prof. Sir John Enderby P r o f . P e t e r E g e l s t a f f Alan K Soper FRS, ISIS Facility, STFC Rutherford Appleton Laboratory, UK First order difference method Alan K Soper FRS Scattering
SLIDE 2
SLIDE 3
Scattering neutrons off water – reactor neutron source.
Attempt to use hydrogen isotopes:
- Large recoil effect...
Alan K Soper FRS
The Institut Laue Langevin reactor, Grenoble. D4C instrument at ILL
SLIDE 4
To solve the recoil problem:
Alan K Soper FRS
1) Go to a pulsed neutron source. 2) Use high neutron energies, small scattering angles. 3) Use a third (mixture) sample.
SLIDE 5
1) Go to a pulsed neutron source.
Alan K Soper FRS
SLIDE 6
2) Use high neutron energies, small scattering angles.
Alan K Soper FRS
SLIDE 7
3) Use a third (mixture) sample.
Alan K Soper FRS
SLIDE 8
Introduce EPSR computer simulation...
- Aim: to get a structural model of the
system being studied.
- Method: Like computed tomography.
- Data act as constraint on structure, but do
not define it. Alan K Soper FRS
SLIDE 9
Sorbitol in Water at 100K
Alan K Soper FRS
Before After
SLIDE 10
Method is taking off!
Alan K Soper FRS
Water in MCM41 pores Water under pressure AOT/Isooctane reverse micelles Polyethylene oxide...
SLIDE 11
Water under pressure
Alan K Soper FRS
0.3 kbar
SLIDE 12
Water under pressure
Alan K Soper FRS
2.1 kbar
SLIDE 13
Water under pressure
Alan K Soper FRS
4.0 kbar
SLIDE 14
Water in MCM41 pores
Alan K Soper FRS
SLIDE 15