Tuesday 4:30 pm (Freiburg) / 7:30 am (Vancouver)
14.04.26 – Merline Cherukarathadathil Ulahannan
(University of Freiburg)
21.04.26 – Maria Popovic (University of Milan, Italy)
28.04.26 – Alexie Boyer (University of Strasbourg, France)
05.05.26 – Krzysztof Jachymski (University of Warsaw, Poland)
12.05.26 – Martin Pichotka (University of Freiburg)
19.05.26 – Manuel Gessner (University of Valencia, Spain)
02.06.26 – Frank Schlawin (University of Hamburg)
16.06.26 – Iva Brezinova (TU Vienna, Austria)
23.06.26 – Peter Ratzikis (IESL-FORTH, Greece)
30.06.26 – Madhusree Roy-Chowdhury (University of Kassel)
14.07.26 – Nicolas Treps (Sorbonne University, France)
14.04.26 – Merline Cherukarathadathil Ulahannan (University of Freiburg)
Design for a Monochromatic, High-Repetition-Rate XUV Beamline for Time-Resolved Photoelectron–Photoion Coincidence Spectroscopy
In the first part of this talk, I will present my Master’s project carried out at TIFR Hyderabad, where I worked on building a laser-driven X-ray diffraction apparatus. Using a kHz femtosecond Ti:Sapphire laser (800 nm, 25 fs, 2.5 mJ, 1 kHz) focused onto a 20 μm methanol jet in vacuum, I generated a hot dense plasma producing highly energetic electrons (~2 MeV). The resulting highly energetic electrons was used for generating X-rays (~8 keV) which we tried to use for XRD.
In the next section I present our plans for a monochromatic XUV beamline with high-repetition rates of up to 120 kHz for time-resolved photoelectron photoion coincidence spectroscopy. The beamline will be based on a cascaded harmonic generation scheme [1] driven by an Yb Laser. The 800 μJ near IR pulses will be first spectrally broadened by self-phase modulation in a gas-filled multipass cell and compressed to ~40, after which the pulse is passed through a BBO crystal to generate the second harmonic (515 nm). The resulting pulses will be used to efficiently drive the HHG process in a gas jet producing XUV radiation in the range between 10 and 20 eV. After separation of the XUV from the driving field we will use a time-preserving monochromator [2] with a single plane diffraction grating in off-plane geometry for spectral selection while maintaining pulse durations of tens of femtoseconds.
A home-built nonlinear optical parametric amplifier pumped by the same Yb Laser will supply frequency-tunable ultrashort pump pulses in the visible and UV spectral range. This beamline will be used in performing time-resolved XUV photoelectron–photoion coincidence spectroscopy in molecular complexes.
References:
- Comby et al., Opt. Express 27, 20383 (2019).
- Frassetto et al., Opt. Express 19, 19169 (2011).
Chair: Sebastian Hartweg
