Kinematically complete study of photoreactions in molecules

Domain topic

Atomic and Molecular Physics

Supervisors

Motivation

Improved understanding of matter dynamics on an atomic level is essential in order to meet current societal challenges such as climate change, development of advanced materials, or energy production and storage. Applications of atomic and molecular science are currently evolving toward complex systems such as large- molecules and clusters, which are aggregates of atoms or molecules, where important discoveries are foreseen in the areas of ultrafast energy transfer and energy conversion mechanisms at the atomic scale. During the past decades, charged-particle velocity-vector-imaging spectrometers have revolutionized atomic, molecular, and cluster science. These advanced detection techniques allow for the realization of kinematically complete experiments of photoreactions, usually induced after the absorption of a high-energy photon, by measuring the momentum of emitted charged particles, the kinetic energy and angular correlations between particles. These spectrometers have been used to investigate the quantum four-body problem, fundamental paradigms in quantum physics such as the localization/delocalization of electron vacancies in molecules, ultrafast dissociation, interatomic/molecular coulombic decay, and more recently, elusive three-particle Efimov states.

Project Description

Here, we shall develop even improved spectrometers for the challenging high-resolution, high-count-rate, multi-particle detection necessary in a foreseeable future. On the one hand, we shall push the frontiers of the number as well as the mass of detectable particles with 3D detectors in order to observe such very detailed information for ever larger and more complex supermolecular systems, e.g., by moving the mass limit from 1000 u to 20000 u. This is achieved by a combination of high-voltage detectors, significantly faster digitizers, and improved signal processing and analysis. At the same time will we extend the applicability of 2D detector through the use of very-high-time-resolution detectors with multi-hit capabilities, such as time-stamping pixelated detectors, e.g., Timepix3, or high-speed delay-line hexanodes.

Methodological keywords

Electronics, detectors, simulation start-to-end & optimization, Model based & model less data analysis