S(Q,ω) and I(Q,t)

Abstract

At its simplest, analysis of EFWS and/or IFWS data informs, via inflexions or peaks, where quasi-elastic processes enter, and leave, the experimental time window of a neutron instrument. It thus follows to explore these regions in greater detail to extract further descriptive parameters via analysis of dynamic structure factors, S(Q,ω), and/or intermediate scattering functions, I(Q,t). This chapter describes common S(Q,ω) and I(Q,t) analysis protocols, the relative merits and limitations of analysis in the time domain, compared to energy space, and summarises the responses expected from specific dynamic phenomena. Analysis strategies and modelling suggestions are also given. The chapter concludes by guiding the reader towards toward alternative, yet complementary, resources.