Results 81 to 90 of about 208,703 (312)

Real-time observation of a correlation-driven sub 3 fs charge migration in ionised adenine

Communications Chemistry, 2021
Sudden ionisation of larger molecules can initiate a correlation-driven process called charge migration, but due to its short time scale this process is challenging to observe.
Erik P. Månsson, Simone Latini, Fabio Covito, Vincent Wanie, Mara Galli, Enrico Perfetto, Gianluca Stefanucci, Hannes Hübener, Umberto De Giovannini, Mattea C. Castrovilli, Andrea Trabattoni, Fabio Frassetto, Luca Poletto, Jason B. Greenwood, François Légaré, Mauro Nisoli, Angel Rubio, Francesca Calegari   +17 more
doaj   +1 more source

Creating Ti–Fe α/β Alloys by Diffusion‐Driven Solid‐State Processing

Advanced Engineering Materials, EarlyView.
This study proposes making alloys containing fast diffusing elements that are difficult to produce by ingot metallurgy, by diffusion‐driven solid‐state HIP processing of elemental powders and low‐temperature homogenisation. Here, novel Fe‐Ti α–β alloys are formed having fine α–β lamellae, a small β prior grain size without significant intermetallics ...
Jiaqi Xu, Xun Zhang, Jack M. Donoghue, Albert D. Smith, Rahul Unnikrishnan, Rhys Thomas, Vahid Nekouie, Jie Luo, Dongchen Hu, Michael Preuss, Philip J. Withers   +10 more
wiley   +1 more source

Single-electron Nano-chip Free-electron Laser

, 2022
A conventional free-electron laser is useful but large, driven by a beam with many relativistic electrons. Although, recently, keV electron beams have been used to excite broadband radiation from material chips, there remains a quest for a chip-size free-
Luo-Hao Peng (14416305), Wei-Chih Wang (12412945), Karthickraj Muthuramalingam (14416311), Hossein Shirvani (14416308), Yen-Chieh Huang (2309230), Wen-Chi Chen (286343)   +5 more
core   +2 more sources

Electron pressure drives THz phonons in metal–metal superlattices

Nature Communications
Ultrafast control of lattice motion in metals is a central challenge for high-frequency strain engineering and spintronic applications. Coherent strain control at terahertz (THz) frequencies in metals has remained elusive because free electrons are ...
Jan-Etienne Pudell, Maximilian Mattern, Marc Herzog, Alexander von Reppert, Chandan K. Singh, Daniel Schick, Michel Hehn, Ulrike Boesenberg, Angel Rodriguez-Fernandez, Roman Shayduk, Wonhyuk Jo, Johannes Möller, Jörg Hallmann, James Wrigley, Peter M. Oppeneer, Anders Madsen, Matias Bargheer   +16 more
doaj   +1 more source

Complete Electric Field Characterization of Ultrashort Multicolor Pulses

Ultrafast Science
The advancement of laser technology, producing increasingly shorter and more intricate optical pulses, has elevated the significance of precise characterization of a transient electric field, including the carrier-envelope phase.
Maximilian Kubullek, Miguel A. Silva-Toledo, Roland E. Mainz, Fabian Scheiba, Rafael de Q. Garcia, Felix Ritzkowsky, Giulio Maria Rossi, Franz X. Kärtner   +7 more
doaj   +1 more source

Gain and coherence enhancement of SASE FEL using laser-prebunched electrons

, 2012
[[abstract]]We conduct a simulation study on the acceleration of periodically loaded electrons in a 6-MeV photocathode electron gun driven by a laser beat wave with a beat frequency of 4.35 THz.
Yen-Chieh Huang;Chia-Hsian Chen
core  

Wide-bandwidth mode-hop-free tuning of extended-cavity GaN diode lasers

, 2005
We present a new approach for extended-cavity diode-laser tuning to achieve wide mode-hop-free tuning ranges. By using a multiple piezoactuated grating mount, the cavity length and grating angle in the laser can be adjusted independently, allowing mode ...
Burns, I.S., Kaminski, C.F., Hult, J.
core   +1 more source

A Mirrorless Photonic Free-Electron Laser Oscillator [PDF]

, 2017
Photonic crystals have been used to provide fundamental control over the interaction between light and matter, including stimulated emission. For example, in Bloch-mode lasers, the photonic crystal provides field enhancement through reduced group ...
van der Slot, P.J.M.; id_orcid, Boller, Klaus J., van der Slot, Petrus J.M.; id_orcid, Denis, T., van der Slot, Petrus J.M., P. J. M. van der Slot, Strooisma, A., van der Slot, P.J.M., A. Strooisma, T. Denis, K.-J. Boller   +10 more
core   +1 more source

Performance Analysis of Abradable Coating Systems for Aircraft Gas Turbines

Advanced Engineering Materials, EarlyView.
Three CoNiCrAlY/YSZ/MgAl2O4 abradable liner configurations on a nickel‐superalloy are evaluated by thermal‐gradient cycling and incursion tests. Laser ablation of the bondcoat and/or Y2O3‐stabilized ZrO2 (YSZ) intermediate layer increases mechanical interlocking and bonding for thick topcoats.
Hanna Heyl, Daniel Emil Mack, Martin Tandler, Susanne Schrüfer, Robert Vaßen   +4 more
wiley   +1 more source

Nonlinear harmonic generation in free-electron laser oscillators

, 2004
Nonlinear harmonic generation has been described theoretically, and observed, in free-electron laser (FEL) amplifiers. The mechanism relies on the nonlinear, higher-order bunching when the fundamental reaches high intensities, and can also be expected in
O'Shea, PG, Freund, HP, Lund University., Biedron, Sandra G.,   +3 more
core   +1 more source