PhD& PostdocPositions at TU Dortmund, Germany

Spectroscopy with angular resolutionfor ultrafastexperiments atX-ray FELs

Project Description: For the investigation of the fundamental excitation processes in atoms and molecules it is necessary to observe their dynamics in real time. Specifically, the electrons’ motion is played out on femtosecond (fs) and attosecond (as) time scales, which are comparable to a single oscillation period of the electromagnetic field for the optical wavelength range (2.7 fs at 800 nm). Even shorter “pump” pulses to trigger the studied molecular changes necessitate driving wavelengths in the extreme ultraviolet (XUV) and X-ray regime. These ultrashort pulses can best be produced at X- ray free-electron lasers (XFELs) like the European XFEL in Hamburg or the LCLS in California, USA. In the framework of a project funded by the German Bundesministerium für Bildung und Forschung (BMBF) we are developing a novel detection method for a class of ultrafast experiments that combine high energy, spatial and temporal resolution with high repetition rates. The envisioned detector consists of multiple, circularly arranged time-of-flight (TOF) tubes for the simultaneous measurement of electron or ion kinetic energies in arbitrary directions of the transverse plane.

Position: We offer PhD & Postdoc positions in the fields of experimental X-ray laser physics and ultrafast electron spectroscopy. The candidates will join the group of Jun.-Prof. Wolfram Helml at TU Dortmund*, where the synchrotron source DELTA is available for X-ray related experiments and instrument tests. In addition, there exists a state-of-the-art femtosecond optical laser system as a complimentary light source for lab-based experiments. For this project, part of the work for the initial detector setup will also be done at the European XFEL/Hamburg, with which we pursue a long- standing and fruitful collaboration. Close connections also exist with experts from the Helmholtz Zentrum Berlin (BESSY) the SwissFEL and the LCLS, opening the prospect of scientific exchange at world-leading facilities and unique experimental capabilities.

Qualification: We are seeking candidates with experimental experience in electron spectroscopy, ultrashort laser or X-ray-related work and/or knowledge of detector design and construction. Familiarity with SIMION and Matlab/Python for simulations and data analysis as well as Inventor or SolidWorks for 3D design of the detector are desirable. Above all, we value a broad interest for all kinds of physical problem solving and an open mind for working in a team. The candidate must hold a Master/PhD degree in physics or a related subject.

Application procedure: Suitable candidates are requested to submit a short Curriculum Vitae, including a copy of their relevant degrees and providing full address, a contact phone number and email address. For further information on the research project, the position or organizational details, as well as for submitting an application, please directly contact Wolfram.Helml@tu-dortmund.de.

Applications are open from the beginning of June 2020 until the positions are filled!

* Some relevant recent publications:
Haynes, D. C.
et al. Clocking Auger Electrons. arXiv.org (2020).
N. Hartmann
et al. Attosecond time–energy structure of X-ray free-electron laser pulses. Nat. Photonics 12, 215– 220 (2018).
W. Helml
et al., Ultrashort Free-Electron Laser X-ray Pulses. Appl. Sci. 7, 915–956 (2017).