Multi-particle momentum correlations extracted using covariance methods on multiple-ionization of diiodomethane molecules by soft-X-ray free-electron laser pulses

Abstract

Correlations between the ion momenta are extracted by covariance methods formulated for the use in multiparticle momentum-resolved ion time-of-flight spectroscopy.

Multi-channel photodissociation and XUV-induced charge transfer dynamics in strong-field-ionized methyl iodide studied with time-resolved recoil-frame covariance imaging

“…However, correlated information can still be extracted through covariance analysis 35,49 . Initially this was applied to determine correlations between different dissociative ionization channels in the Coulomb explosion dynamics of small molecules, but the approach has subsequently been extensively developed for other applications 49 , particularly in FEL science [50][51][52][53] . Briefly, covariance is a measure of the linear correlation of two variables, X and Y, defined as: Covariance(X,Y…”

X-ray induced ultrafast dynamics in atoms, molecules, and clusters: experimental studies at an X-ray free-electron laser facility SACLA and modelling

“…The present findings may validate the 'diffraction-beforedestruction' approach of single bio-macromolecules and protein microcrystals, as long as the hydrogen atoms can be neglected, and also suggest the importance of understanding influences of charge dynamics that occur within the X-ray-pulse duration to the X-ray scattering. We have also been conducting spectroscopic experiments using soft-X-ray FEL [49][50][51] and X-ray diffraction experiments [52][53][54][55] at SACLA, though these attempts were not described in the present review article. We believe that electronic and structural dynamics in various forms of matter will be investigated extensively employing XFELs all over the world and we hope that our attempts described in this article will contribute to such investigations.…”

Atomic, molecular and optical physics applications of longitudinally coherent and narrow bandwidth Free-Electron Lasers

“…Regarding this experiment, we note that a crucial breakthrough in permitting the "sculpture" of pulses was the use of intensity correlation methods. This is a form of covariance analysis, which was implemented some time ago for optical lasers (Frasinski et al, 1989), as well as more recently for FELs (Frasinski et al, 2013;Kornilov et al, 2013;You et al, 2020a): we expect to see increasing applications of correlation techniques. A recent example is ghost spectroscopy, or "spooktroscopy" (Driver et al, 2020).…”