1. Next Generation Science with Inelastic X-ray Scattering
Clement Burns
Western Michigan University
Thanks to:
Yuri Shyvd’ko, Ercan Alp, Ayman Said (APS)
Peter Abbamonte (UIUC)
Zahid Hasan (Princeton)

2. Six Challenges for Physics
National Research Council Review of Physics (2001)
Developing quantum technologies
Understanding complex systems
Applying physics to biology
Creating new materials
Exploring the universe
Unifying the forces of nature
NRC for physics

3. Energy - Momentum Relationships

4. Focus with X-ray Mirrors Small Beam
High flux for experiments
IXS flux hungry technique
>1016 P=photon/sec-0.1% bandwidth
Small beam size (<4 x 40 mm2)
High pressure work
Nanomaterials
New materials
E.g., MgB2
Devices
Surfaces
Environmental
But… start 2014
                                          
NSLS II
1014 photons 100 meV width at 10 keV, 1012 at 1 meV
Don’t just do the same experiments
/Highlights/2002/Imaging/IMA8/fig103

5. Science with 0.1 meV Resolution

6. Need for Higher Resolution
DNA Liu, J. Chem. Phys. 123,
1.5 meV Sette
Johnny von Neumann used to say, 'with four parameters I can fit an elephant and with five I can make him wiggle his trunk quote by Fermi
Pilla et al, PRL 85, 2136 (2000)
DNA Krisch PRE 73,
DHO
Memory Fun.

7. Science at 0.1 meV
1 meV resolution does not mean one can study excitations with an energy of 1 meV
Large background from elastic
High resolution and good elastic rejection
From Yuri Shvyd’ko

8. Reinstäder, Phys. Rev. Lett. 93, 108107 (2004)
Possible Science
Low energy excitations in polymers
Related to wetting, adhesion..
Lipid membranes
Mapping superconducting band gap with phonons
Dynamics of glasses
Lipids fat soluble molecules (includes cholesterol)
Inoue, PRL 95, (2005)
Reinstäder, Phys. Rev. Lett. 93, (2004)

9. 0.1 meV Science
BRISP Neutron Brillouin IUVS inelastic ultraviolet scattering,
From Ruocco

10. Science with 1 meV Resolution

11. Some Ideas at 1 meV
Extreme environments – low temperature, high field, ultrahigh pressure
Small samples
Down to nanoparticle size
(High pressure)
Surface phonons
Grazing incidence requires small beam
10’ yields ~1.5 mm on sample
Most current techniques require high vacuum
Exotic excitations
Orbitons
Resonant scattering?
Pulse probe technique – phonons in excited states
Can also do scattering under other extreme environments – high field, low temperature

12. Extreme Environments High pressure High Temperature
Levitated Liquids
High pressure
High Temperature
High magnetic fields
Low temperature
Heating issues
Sinn, Science 299, 2047 (2003)

13. Small Samples New materials – e.g., phonons in MgB2
Samples/regions in crystals - Pu
Really small ?
100 nm? Smaller?
Nanotubes?
Wong et. al, Science 301, 1071 (2003)

14. Surface Phonon Scattering
IXS can do both on same sample
2-d behavior important for devices as well as fundamental science
Thin films (need to compare to e.g., He scattering)
Buried interfaces?
Study 2-d behavior liquids
Murphy et. al, PRL 95, (2005)

15. Case for Medium Resolution
It’s a “slam dunk” – as strong as the case for meV or sub meV

16. Science at Medium Resolution
Electronic excitations
Plasmons, excitons, spinons, holons, Mott gap, band transitions, superconducting gap….
Non-resonant scattering – easy comparison to (q,)
Resonant scattering –site and state selective
Soft x-ray edges at high energy
Time evolution of systems
Study highly correlated electron systems, Mott-Hubbard insulators, organic semiconductors, regular metals, …new systems everyday

17. Scattering Cross Section
From Platzman and Isaacs, PRB 57, (1998)
Non-resonant Scattering

18. Medium Resolution Work
IXS Organic Molecular Crystal
Spinon-holon
Yang et al., PRL 98, (2007)
Y. Cai, et al, Phys. Rev. Lett. 2006
June et al., PRL (2004)
Kodituwakku et al, submitted to PRL

19. Medium Resolution RIXS Opportunities

20. Resonant Scattering Energies

21. Medium Resolution – Monochromator Improvements
Tom Toellner, APS
Four bounce
High efficiency
Wide energy range

22. Medium Resolution Spectrometer Detector Improvements
Line detector
Huotari et al., ESRF
Shvyd’ko APS
Improve counts
Larger solid angle
Improve resolution
Reduces geometric effect
Other energies?
S. Huotari et al., Journal of Synchrotron
Radiation 20, (2005).

23. Why do we need NSLS-II? Smaller samples can be studied
New materials, high pressure
Many, many systems to look at
Higher resolution - necessary for many cases…

24. Low Resolution Options Important!
Dynamics on attosecond time scales
From Peter Abbamonte

25. Low / Adjustable Resolution
Dipole forbidden d-d excitations
Information about
Larson et al., PRL 99, (2007)

26. Observations No one cares how good the NSLS-II synchrotron is ….
They care about the quality of science
Many good ideas for IXS
Throw out most of them
Use strengths of NSLS-II
Develop early – detectors, etc.
Room for future ideas
Adjustable resolution
Support
Sample orientation/alignment
Characterization (other departments?)