Results 51 to 60 of about 27,457 (262)

Quantum regime of free electron lasers starting from noise

Physical Review Special Topics. Accelerators and Beams, 2006
We investigate the quantum regime of a high-gain free-electron laser starting from noise. In the first part, we neglect the radiation propagation and we formulate a quantum linear theory of the N-particle free-electron laser Hamiltonian model, quantizing
R. Bonifacio, N. Piovella, G. R. M. Robb, A. Schiavi   +3 more
doaj   +1 more source

The Oxford free electron laser project

Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 1990
It is proposed to use the Oxford 10 MV Van de Graaff accelerator as an electron beam source for a free electron laser (FEL) operating in the far infra red (FIR). The configuration and layout of the Van de Graaff make it very suitable for conversion, with a potentially high efficiency for electron beam recovery. Using a 2 m long wiggler of 34 mm period,
Allison, W, Brau, C, Brooks, C, Doucas, G, Elgin, J, Gillespie, W, Holmes, A, Jaroszynski, D, Kimmitt, M, Martin, P, Mulvey, J, Pidgeon, C, Poole, M   +12 more
openaire   +2 more sources

Understanding the Stochastic Nature of Process Parameter Development of Blown Powder Laser Beam Directed Energy Deposition Additive Manufacturing of Pure Molybdenum

Advanced Engineering Materials, EarlyView.
Identified through the use of statistical design of experiments and metallographic investigation, this study exposes the stochastic origins of intergranular cracks in blown powder laser beam directed energy deposition additive manufacturing of pure molybdenum. It further demonstrates a successful crack mitigation approach with direct correlation to the
Nathaniel J. Lies, Daniel E. Driemeyer, Aaron P. Stebner   +2 more
wiley   +1 more source

Beam conditioning for free electron lasers: Consequences and methods

Physical Review Special Topics. Accelerators and Beams, 2004
The consequences of beam conditioning in four example cases [VISA, a soft x-ray free-electron laser (FEL), LCLS, and a “Greenfield” FEL] are examined. It is shown that in emittance limited cases, proper conditioning reduces sensitivity to the transverse ...
A. Wolski, G. Penn, A. Sessler, J. Wurtele   +3 more
doaj   +1 more source

Fatigue Crack Initiation and Growth in Nanocrystalline Ni at Multiple Length‐Scales

Advanced Engineering Materials, EarlyView.
Overview of miniaturized in situ SEM fatigue setup and resultant fatigue crack growth data for nanocrystalline Ni. The presented study focuses on the analysis of fatigue crack growth rate (FCGR) in focused ion beam‐notched microcantilevers prepared from nanocrystalline (NC) Ni as a model material.
Igor Moravcik, Alexander Jelinek, Markus Alfreider, Jutta Luksch, Anton Hohenwarter, Florian Schaefer, Christian Motz, Daniel Kiener   +7 more
wiley   +1 more source

Model-based optimization of tapered free-electron lasers

Physical Review Special Topics. Accelerators and Beams, 2015
The energy extraction efficiency is a figure of merit for a free-electron laser (FEL). It can be enhanced by the technique of undulator tapering, which enables the sustained growth of radiation power beyond the initial saturation point.
Alan Mak, Francesca Curbis, Sverker Werin   +2 more
doaj   +1 more source

Current Status and Challenges in Data Collection for Aerospace Coatings Deposited by Plasma Spraying

Advanced Engineering Materials, EarlyView.
An innovative approach has been integrated into the GRENAT project to optimize plasma spraying and coating performance. Raw materials are accelerated and melted in the plasma generated by torches, creating coatings. Monitoring sensors collect process data which are combined with ex situ characterization data.
Lila Randriamananjara, Vincent Rat, Quentin Dubreuil, Patrice Valorge, Simon Goutier, Alain Denoirjean, Olivier Messe, Céline Ruelle, Jean‐Philippe Poli   +8 more
wiley   +1 more source

Two-bunch seeding of soft x-ray free electron lasers

Physical Review Accelerators and Beams
Seeded free electron lasers (FELs) demonstrate a good performance and are successfully used in different user experiments in extreme ultraviolet and soft x-ray regimes.
E. Schneidmiller, I. Zagorodnov
doaj   +1 more source

Atomic inner-shell radiation seeded free-electron lasers

Physical Review Accelerators and Beams, 2018
In order to effectively improve the output quality of x-ray free electron laser (XFEL), we theoretically propose an XFEL scheme seeded by atomic inner-shell laser.
Han Zhang, Kai Li, Jiawei Yan, Haixiao Deng, Baoyuan Sun   +4 more
doaj   +1 more source

Inverse Identification of Energy‐Dependent Laser Absorptivity in NiTi Laser Powder‐Bed Fusion via Calibrated Melt Pool Simulation

Advanced Engineering Materials, EarlyView.
A combined experimental–computational framework identifies energy‐dependent laser absorptivity for NiTi in laser powder‐bed fusion, applicable to conduction and transition modes. Single‐track experiments and thermofluid smoothed particle hydrodynamics simulations are coupled through inverse analysis of melt pool geometry.
Mohamadreza Afrasiabi, Hadi Moutablaleh, Ignatius A. Setiawan, Mehrshad Mehrpouya   +3 more
wiley   +1 more source