Physicist · Senior Researcher
Dr. Stefan Funkner
Phase-space tomography, ultrafast electron bunch diagnostics and inverse problems in accelerator physics.
- Since 2017
- Senior Researcher, IBPT, KIT
- Dr. rer. nat.
- Ruhr-Universität Bochum
- JSPS Fellow
- University of Fukui, Japan
- Feodor Lynen
- Return Fellowship, Humboldt Foundation
About
I am a physicist and staff scientist at the Institute for Beam Physics and Technology (IBPT) at Karlsruhe Institute of Technology (KIT). My research combines mathematics, physics, and computational methods to investigate the dynamics of electron bunches in particle accelerators.
Recently, I demonstrated how advanced electro-optical measurements can be combined with accelerator-specific electron-bunch dynamics to reconstruct the bunches’ phase-space density at KIT’s KARA research accelerator.
My research journey began in mathematical physics at Leipzig University, where I explored differential geometry and quantum gravity, focusing on the geometry of Ashtekar variables. For my PhD, I moved to Ruhr University Bochum, where I investigated aqueous solutions using terahertz spectroscopy. I then continued my research at the Research Center for Development of Far-Infrared Region in Fukui, Japan, developing a novel approach to coherent stimulated Raman scattering in the terahertz range.
Lines of inquiry
Phase-space tomography
Reconstructing how electrons are distributed in longitudinal position and energy from electro-optical measurements, revealing how microstructures form and evolve within electron bunches.
Ultrafast diagnostics
Developing electro-optical and THz-sensitive diagnostics for electron bunches, from MHz-rate measurements of longitudinal profiles to the characterization of transient near-fields in particle accelerators.
Inverse problems
Developing mathematical and numerical methods to recover unknown quantities from indirect observations, with a focus on the stability and reliability of the reconstruction.
Terahertz light
Probing intermolecular interactions, hydrogen-bond dynamics, and solvation shells in liquids using terahertz and nonlinear Raman spectroscopy.
Four stations
From mathematical physics via the chemistry of water to accelerator physics.
-
Leipzig
until 2005Mathematical physics
Diploma in Physics, Institute of Theoretical Physics, Universität Leipzig. Followed by additional qualifications in human genetics and molecular biology.
-
Bochum
2007–2013Terahertz spectroscopy
PhD (Dr. rer. nat., 2007–2011) and postdoc (2012–2013), Physical Chemistry, Prof. Havenith, Ruhr-Universität Bochum.
-
Fukui, Japan
2013–2015Lasers & THz Raman
JSPS Postdoctoral Fellow (2013–2015), then Assistant Professor (2015), Research Center for Development of Far-Infrared Region, Prof. Tani.
-
Karlsruhe
since 2015Accelerator physics
Feodor Lynen Return Fellow at LAS, KIT (2015–2016). Senior Researcher at IBPT, KIT, since 2017.
Selected first-author publications
All publications →Citation counts as of October 2026.
-
2023Revealing the dynamics of ultrarelativistic non-equilibrium many-electron systems with phase space tomography18 citations
-
2019High throughput data streaming of individual longitudinal electron bunch profiles41 citations
-
2014Utilization of chirped laser pulses to measure stimulated Raman scattering of organic liquids in the terahertz regime13 citations
-
2012Watching the low-frequency motions in aqueous salt solutions: the terahertz vibrational signatures of hydrated ions320 citations
-
2012Urea, a structure breaker? Answers from THz absorption spectroscopy97 citations
Work contact
Karlsruhe Institute of Technology (KIT)Institute for Beam Physics and Technology
Dr. Stefan Funkner
Building 345
Hermann-von-Helmholtz-Platz 1
76344 Eggenstein-Leopoldshafen, Germany