Alan Hewat, NMUM 10-11 Jan 2002

The ILL Millennium Programme in DiffractionAlan Hewat, ILL Diffraction Group Leader

Alan Hewat, NMUM 10-11 Jan 2002

The ILL Millennium Programme in Diffraction

� New 10 year ILL contract just signed

� Millennium Programme -> ILL machines by x10 to x20

� New detector and neutron optic technology

� Infrastructure renewal – super-mirror guides, hot source

Alan Hewat, NMUM 10-11 Jan 2002

New Instruments:

� D2b – high resolution powder diffractometer with linear PSDs

� D20 – a large microstrip detector for chemical kinetics…

� D4c – a microstrip detector for liquids & amorphous materials

� D19 – an array of 2D-microstrips for protein/fibre diffraction

� VIVALDI – Laue Diffractometer with Neutron Image Plate

� Strain Scanner – for mapping strain using microstrip detectors

� D3 polarised neutron diffractometer (polarimetry & He3 filter)

The ILL Millennium Programme in Diffraction

Alan Hewat, NMUM 10-11 Jan 2002

The ILL Millennium Programme

� D2B –very high resolution, good intensity (Rietveld)Current EPSRC proposal for Super-D2B

� D20 – very high intensity, good resolution (kinetics)Microstrip detectors, high speed electronics, big focussing monochromators

(future Super-D20 proposal for a much larger PSD detector)

Alan Hewat, NMUM 10-11 Jan 2002

Super-D2B High Resolution Powder Diffractometer

Metal hydrides BaReH9

A high precision powder diffractometer – high resolution plus high flux

cf HRPD at ISIS

New metal hydrides, new phases of ice/clathrates, charge order in CMR, high Tc etc

Valence Sum V=Σi[exp(Ro-Ri)/B]

High pressure ice/clathrates

Alan Hewat, NMUM 10-11 Jan 2002

Super-D2B High Resolution Powder DiffractometerCharge order, Mixed valence, CMR materials, Magnetism…

M(Ni1) = -1.4 µµµµBM(Ni2) = 0.7 µµµµB

Combined ESRF, D1B and D2B data - Alonso J.A. et al (1999) PRL 82, 3873

Metallic Ortho. YNiO3 -> Insulating Mono. YNiO3 T < 582K Ni valence 3-δ, 3+ δ

V(Ni1) = 2.62 V(Ni2) = 3.17

Ni1 Ni2

� Double evidence for charge transfer� Magnetic superstructure and different moments on Ni-sites

� Different Ni-O distances around Ni1 and Ni2 sites mean ‘charge transfer’

� Neutrons provide both. But need:� High resolution to resolve symmetry

� High flux to see superstructure

� Small samples – again high flux

Alan Hewat, NMUM 10-11 Jan 2002

Large pseudo-2D PSD (array of 5’ collimators & linear-wire detectors)

� 2D detector allows both high efficiency & high resolution

Super-D2B High Resolution Powder DiffractometerCurrent EPSRC proposal of Paul Attfield et al. Cambridge

Alan Hewat, NMUM 10-11 Jan 2002

The 160o D20 Microstrip Arraycf GEM at Isis

25 plates of 64 electrodes are assembled to produce a 1600-wire detector covering 160o.

Alan Hewat, NMUM 10-11 Jan 2002

Explosive Reactions create New Materials

In-situ neutron powder diffraction at 0.9s time resolution. Daniel Riley, Erich Kisi et al.

“How do we create a material that has the high temperature properties of a ceramic, but is electrically conducting like a metal - Ti

3SiC

2”

Complete pattern measured every 0.9 seconds !

Alan Hewat, NMUM 10-11 Jan 2002

The ILL Millennium Programme

� Super versions of both D2B and D20 are planned (big detectors)

� Both D2B and D20 are currently 100% available

Deadlines for proposals: FAST proposals - Sunday 13 January

NORMAL proposals - End of February

On-line submission: “Visitors’ Club” http://vitraill.ill.fr/cv/

Alan Hewat, NMUM 10-11 Jan 2002

An array of Microstrip DetectorsNew D4C Liquids & Amorphous Materials Diffractometer

The new ILL hot source, to be installed soon, will result in x10 intensity

Very high efficiency & stability needed for isotope replacement method

Alan Hewat, NMUM 10-11 Jan 2002

An array of Microstrip DetectorsNew D4C Liquids & Amorphous Materials Diffractometer

Henry Fischer, Gabriel Cuello et al.

Alan Hewat, NMUM 10-11 Jan 2002

The D4c microstrip detector and isotope replacement

The conformation of water around saturated sugar solutionsP.E. Mason, G.W. Neilson, A.C. Barnes, M-L. Saboungi, and G.J. Cuello

6

The very high efficiency and stability of D4c makes the isotope replacement method with very small samples much more powerful.

A first experiment on D4c with hydrogen/deuterium replacement showed that even in 50% saturated glucose solutions, the conformation of water is not much perturbed.

Oxygen

Hydrogen

Carbon

Alan Hewat, NMUM 10-11 Jan 2002

A 2D Microstrip Detector

D9, D10, D15, D-Strain Scanner

A printed circuit on BOTH sides of the glass substrate

2D detectors are now used on all ILL single crystal diffractometers

Alan Hewat, NMUM 10-11 Jan 2002

Artists impression of the new ILL-EPSRC strain scanner behind D1A/D1B

The New ILL-EPSRC Strain Scanner

EPSRC grant of ~ 1M Pounds Sterling to Phil Withers et al. Manchester

Alan Hewat, NMUM 10-11 Jan 2002

An Array of 2D Detectors D19 Fibre & Protein Diffractometer

300x300 mm (128x128) 2D

wire or microstrip detector

Photos show the 200x200mm

prototype already tested on D19

Alan Hewat, NMUM 10-11 Jan 2002

Water in DNA sheets on D19

(a) with H2O (b) with D2O

Present 4° detector

The 15 year old D19 detector covers only a thin 2D strip

Alan Hewat, NMUM 10-11 Jan 2002

9 Independent 2D microstrip detectors

An Array of 2D Microstrip Detectors Successful EPSRC proposal of Judith Howard et al.

� 15 year old D19 detector covers only a thin 2D strip

� Replace with an array of high resolution 2D modules

� Increase efficiency x25

� Fibre DiffractionSmall protein structuresIn-situ hydration studies.

D19 Fibre & Protein Diffractometer

Alan Hewat, NMUM 10-11 Jan 2002

Neutron Image Plates & Microstrip DetectorsClive Wilkinson (Kings) & Dean Myles (EMBL)

Nature (1997) Cover showing LADI data

(LAue Diffractometer with Image plates)

Alan Hewat, NMUM 10-11 Jan 2002

� Neutron guide

� Band of neutron energies

� View reciprocal space

� In-situ laser readout

� Unique survey of P/T

� Phase T/Ns, superstruct.

Dean Myles with LADI and cryo-refrigerator on thermal guide H22

LADI Neutron Image Plate LAue Diffractometer Clive Wilkinson (Kings) & Dean Myles (EMBL)

Alan Hewat, NMUM 10-11 Jan 2002

Neutron Image Plate 5-fold symmetry of quasi-crystal

5-fold symmetry axis in ZnMgY quasi-crystal - De Boissieu et al. (1999)

T-LADI neutron image plate photo courtesy of G. McIntyre, Oct 1999

Alan Hewat, NMUM 10-11 Jan 2002

Neutron Image Plate 5-fold symmetry of quasi-crystal

Rocking the ZnMgY quasi-crystal (Dynamics) – McIntyre, Cowan (1999)

Alan Hewat, NMUM 10-11 Jan 2002

VIVALDI, A New Thermal Neutron Image PlateClive Wilkinson (Kings) & Garry McIntyre

First neutrons before Christmas !!!

� Vertical geometry with cryostat� More efficient internal IP� Faster read-out� Thermal neutron s-mirror guide

� We encourage people to come orsend students for extendedperiods to try this exciting new technique.

Alan Hewat, NMUM 10-11 Jan 2002

• vertical detector to allow extreme sample environments

• single-crystal diffraction will be as ‘easy’ and as fast as powder diffraction

Laue diffraction pattern of incommensurate La2Co

1.7

- within a day of the first neutrons: 23/11/01 !

VIVALDI – Thermal neutron image-platefor physics, chemistry and materials science

Alan Hewat, NMUM 10-11 Jan 2002

Important ILL dates

Deadlines for proposals: FAST proposals - Sunday 13 January

NORMAL proposals - End of February

On-line submission: “Visitors’ Club” http://vitraill.ill.fr/cv/