Publications de Christopher Alexander Arrell

Ultrafast photoelectron spectroscopy of photoexcited aqueous ferrioxalate

Majed Chergui, Michele Puppin, Frank van Mourik, Christopher Alexander Arrell, José Javier Pancracio Ojeda Andara, Luca Longetti, Thomas Roland Barillot

The photochemistry of metal-organic compounds in solution is determined by both intra- and inter-molecular relaxation processes after photoexcitation. Understanding its prime mechanisms is crucial to optimise the reactive paths and control their outcome. H ...

2021

A compact and cost-effective hard X-ray free-electron laser driven by a high-brightness and low-energy electron beam

Majed Chergui, Leonid Rivkin, Giulia Fulvia Mancini, Rasmus Ischebeck, Camila Bacellar Cases Da Silveira, Mike Seidel, Christoph Peter Hauri, Paul Beaud, Christopher Alexander Arrell, Eugenio Ferrari

We present the first lasing results of SwissFEL, a hard X-ray free-electron laser (FEL) that recently came into operation at the Paul Scherrer Institute in Switzerland. SwissFEL is a very stable, compact and cost-effective X-ray FEL facility driven by a lo ...

Nature Publishing Group2020

Photoemission from non-polar aromatic molecules in the gas and liquid phase

Majed Chergui, Frank van Mourik, Christopher Alexander Arrell, Lars-Hendrik Mewes, José Javier Pancracio Ojeda Andara, Jakob Grilj, Luca Longetti

The photoelectron spectra of both liquid and gas phase aromatic molecules are reported. The spectra were obtained using a 34.1 eV source produced by high harmonic generation and analysed with the help of high-level ab initio simulations using the reflectio ...

ROYAL SOC CHEMISTRY2020

Spin cascade and doming in ferric hemes: Femtosecond X-ray absorption and X-ray emission studies

Majed Chergui, Christopher Alexander Arrell, Wojciech Gawelda, Giulia Fulvia Mancini, Camila Bacellar Cases Da Silveira, Frederico Alves Lima, Dominik Kinschel, Oliviero Cannelli, Jérémy Raymond Jean Maurice Rouxel, Rebecca Ann Ingle

The structure-function relationship is at the heart of biology, and major protein deformations are correlated to specific functions. For ferrous heme proteins, doming is associated with the respiratory function in hemoglobin and myoglobins. Cytochrome c (C ...

National Academy of Sciences2020

Experimental station Bernina at SwissFEL: condensed matter physics on femtosecond time scales investigated by X-ray diffraction and spectroscopic methods

Christopher Alexander Arrell, Christoph Peter Hauri, Paul Beaud, Giulia Fulvia Mancini, Jochen Rittmann

The Bernina instrument at the SwissFEL Aramis hard X-ray free-electron laser is designed for studying ultrafast phenomena in condensed matter and material science. Ultrashort pulses from an optical laser system covering a large wavelength range can be used ...

International Union of Crystallography (IUCr)2019

The SwissFEL soft X-ray free-electron laser beamline: Athos

Christopher Alexander Arrell, Christoph Bostedt, Rasmus Ischebeck, Eugenio Ferrari, Thomas Schmidt, Thomas Schietinger, Sven Reiche, Paolo Craievich

The SwissFEL soft X-ray free-electron laser (FEL) beamline Athos will be ready for user operation in 2021. Its design includes a novel layout of alternating magnetic chicanes and short undulator segments. Together with the APPLE X architecture of undulator ...

2019

Coherent generation of symmetry-forbidden phonons by light-induced electron-phonon interactions in magnetite

Oleg Yazyev, Fabrizio Carbone, Frank van Mourik, Christopher Alexander Arrell, Edoardo Baldini, Andreas Helmut Christian Mann, Simone Borroni

Symmetry breaking across phase transitions often causes changes in selection rules and emergence of optical modes which can be detected via spectroscopic techniques or generated coherently in pump-probe experiments. In second-order or weakly first-order tr ...

Amer Physical Soc2017

Harmonium: An Ultrafast Vacuum Ultraviolet Facility

Majed Chergui, Marco Grioni, Marcel Drabbels, Frank van Mourik, Alberto Crepaldi, Christopher Alexander Arrell, Gianmarco Gatti, José Javier Pancracio Ojeda Andara, Luca Longetti, Andrew Daniel Bonnar Clark

Harmonium is a vacuum ultraviolet (VUV) photon source built within the Lausanne Centre for Ultrafast Science (LACUS). Utilising high harmonic generation, photons from 20-110 eV are available to conduct steady-state or ultrafast photoelectron and photoion s ...

Swiss Chemical Soc2017

Clocking the onset of bilayer coherence in a high-Tc cuprate

Fabrizio Carbone, Frank van Mourik, Christopher Alexander Arrell, Edoardo Baldini, Andreas Helmut Christian Mann, Dragan Mihailovic

In cuprates, a precursor state of superconductivity is speculated to exist above the critical temperature T-c. Here we show via a combination of far-infrared ellipsometry and ultrafast broadband optical spectroscopy that signatures of such a state can be o ...

Amer Physical Soc2017

Photoemission and photoionization time delays and rates

Majed Chergui, Ursula Röthlisberger, Christopher Alexander Arrell, Elisa Liberatore

2017