大型放射光施設 SPring-8

Inelastic x-ray scattering (IXS) is one of the success stories of the third generation hard-X-ray synchrotron-radiation sources, opening new fields of endeavor and extending established ones into previously unexplored regimes of sample size (e.g. to microgram samples) and environment. However, despite the high efficiency of the present instruments, IXS, and especially non-resonant IXS, remains severely flux limited.

This workshop will develop the scientific case for a next-generation beamline to investigate dynamics (atomic and electronic) on the (sub)nanometer length scale using IXS: ”NanoDynamics”. The planned instrument will be optimized to perform non- resonant IXS with resolution between 1 and 40 meV over scan ranges up to 10 eV at momentum transfers from 0.l to >10 Å-1. By taking advantage of the particular characteristics of SPring-8 and using x-rays between 15 and 25 keV, the flux will be increased by about an order of magnitude beyond the present generation of instruments. When coupled with spectrometer improvements, this can be expected to lead to as much as a factor of 50 in data rate, enough for a qualitative change in experimental possibilities.

The scientific case for the NanoDyanmics beamline includes (1) extrapolation from present experiments, and (2) new science. Extrapolation from present work can easily be applied to phonons in correlated materials (where many experiments, even with few-day scan times remain flux limited), liquids and glasses where access to extreme environments and also improved resolution and count rates are needed, and samples with geometric constraints, such as those in diamond anvil cells and or surfaces. Meanwhile, momentum-resolved non-resonant electronic scattering is a completely new field, comparable to IR or optical spectroscopy but with the added variable of momentum transfer, allowing direct measurement of inter-atomic correlations (via dispersion in energy or lineshape) and access to the multipole character of electronic transitions.

The goal of the workshop is to bring people together to discuss the possibilities, leading to the writing of a detailed proposal to be submitted in June. We strongly encourage presenting ideas for potential experiments, even if only partially formed.

NanoDynamics Beamline Workshop Program (PDF 100kb)

Organizers
A. Baron, SPring-8, baron@spring8.or.jp
K. Yamada, Tohoku University, kyamada@imr.tohoku.ac.jp
M. Inui, Hiroshima University, inui@mls.ias.hiroshima-u.ac.jp

Administrative
Ms. S. Otsuka, baronsc@spring8.or.jp