Trends in spectroscopy are driven by the quest to understand complex phenomena involving coupled degrees of freedom (e.g. electronic, nuclear, and spin). With the advent of new high brilliance and short pulse sources for time resolved studies, it is expected that different use patterns will emerge using complementary techniques even at different sources to tackle the same problem. The emphasis will be on the understanding of dynamics and function at highest possible spatial, energetic and temporal resolution resulting in multi-dimensional detection schemes and data sets. For example to understand a phase transition it requires the characterization of the stable phase and of transient ones across the entire phase diagram. Also the breakdown of electronic and nuclear motion in molecular dynamics requires multidimensional spectroscopic investigations. This is becoming increasingly possible through complementary spectroscopic experiments at PNI sources. Key scientific examples include:

  • non-equilibrium states in correlated and complex systems on multiple time scales, e.g. ns to #s.
  • functional materials under operating conditions
  • energy transfer, molecular dynamics, and mechanisms of catalysis
The methods involved are:
  • photoemission spectroscopy
  • inelastic X-ray and neutron scattering methods
  • ultrafast spectroscopic methods
  • spectroscopic imaging
  • spin detection and polarization control
  • absorption spectroscopy
For combined, multi-probe studies, the following methods can be applied:
  • electronic structure from high resolution photoelectron spectroscopy
  • low-energy excitation from inelastic X-ray scattering
  • structure factor determination S(q) from neutron scattering
  • time resolved investigation with single pulses from FEL

The data rates in single pulse (e.g. FEL) experiments can be estimated as: 2 x (1k x 1k) detector, 30 Hz image rate, 16 bit, leading to 120MB/sec. This will in the near future increase to: 4k x 4k detectors, 120 Hz image rate, 16 bit, leading to > 5 GB/s. With the advent of the new sources and the establishment of new detector systems, we expect even higher data rates in a few years time.