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Related papers: Automatic tuning of Free Electron Lasers

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A three-dimensional, space-frequency model for simulation of interaction in free-electron lasers (FELs) is presented. The model utilizes an expansion of the total electromagnetic field (radiation and space-charge waves) in terms of…

Accelerator Physics · Physics 2009-11-13 Yosef Pinhasi , Yuri Lurie , Asher Yahalom

X-ray free-electron lasers (XFELs) are powerful tools to explore and study nature for achieving remarkable advances. Generally, seeded FELs are ideal sources for supplying full coherent soft x-ray pulses. Benefiting from the high-frequency…

Accelerator Physics · Physics 2022-07-20 Hanxiang Yang , Jiawei Yan , Zihan Zhu , Haixiao Deng

In this paper we describe a measurement technique capable of resolving femtosecond X-ray pulses from XFEL facilities. Since these ultrashort pulses are themselves the shortest event available, our measurement strategy is to let the X-ray…

Accelerator Physics · Physics 2010-01-21 Gianluca Geloni , Vitali Kocharyan , Evgeni Saldin

In this work we propose an efficient and accurate multi-scale optical simulation algorithm by applying a numerical version of slowly varying envelope approximation in FEM. Specifically, we employ the fast iterative method to quickly compute…

Optics · Physics 2024-12-03 Fan Xiao , Jingwei Wang , Zhongfei Xiong , Yuntian Chen

The x-ray vortex optical beam, distinguished by its topological charge and orbital angular momentum, offers new insights in probing complex electronic structures, enhancing material characterization, and advancing high-resolution imaging…

Optics · Physics 2025-05-26 Zhikai Zhou , Yin Kang , Weishi Wan , Chao Feng

Simulations play a key role for inference in collider physics. We explore various approaches for enhancing the precision of simulations using machine learning, including interventions at the end of the simulation chain (reweighting), at the…

High Energy Physics - Phenomenology · Physics 2023-10-24 Benjamin Nachman , Ramon Winterhalder

The parameters tuning of event generators is a research topic characterized by complex choices: the generator response to parameter variations is difficult to obtain on a theoretical basis, and numerical methods are hardly tractable due to…

Computational Physics · Physics 2021-03-17 Marco Lazzarin , Simone Alioli , Stefano Carrazza

We describe a new method to produce intensity stable, highly coherent, narrow-band x-ray pulses in self-seeded free electron (FEL) lasers. The approach uses an ultra-short electron beam to generate a single spike FEL pulse with a wide…

Accelerator Physics · Physics 2020-07-29 Erik Hemsing , Aliaksei Halavanau , Zhen Zhang

X-ray free electron laser (XFEL) experiments have brought unique capabilities and opened new directions in research, such as creating new states of matter or directly measuring atomic motion. One such area is the ability to use finely…

Accurate extrinsic sensor calibration is essential for both autonomous vehicles and robots. Traditionally this is an involved process requiring calibration targets, known fiducial markers and is generally performed in a lab. Moreover, even…

Robotics · Computer Science 2021-03-18 Celyn Walters , Oscar Mendez , Simon Hadfield , Richard Bowden

Ensemble learning is a mainstay in modern data science practice. Conventional ensemble algorithms assigns to base models a set of deterministic, constant model weights that (1) do not fully account for variations in base model accuracy…

Machine Learning · Computer Science 2018-12-20 Jeremiah Zhe Liu , John Paisley , Marianthi-Anna Kioumourtzoglou , Brent A. Coull

There are many different nature-inspired algorithms in the literature, and almost all such algorithms have algorithm-dependent parameters that need to be tuned. The proper setting and parameter tuning should be carried out to maximize the…

Computation · Statistics 2025-04-29 Geethu Joy , Christian Huyck , Xin-She Yang

A concept for continuously tunable titanium-sapphire (Ti:Sa) lasers using dispersion prisms is under investigation for the ARIEL (Advanced Rare IsotopE Laboratory) laser ion source at TRIUMF (Canada's particle accelerator center).…

Optics · Physics 2020-01-29 Bianca Bettina Reich , Maryam Mostamand , Ruohong Li , Jens Lassen

We present a comprehensive analysis of coherence properties of the radiation from X-ray free electron laser (XFEL). We consider practically important case when XFEL is optimized for maximum gain. Such an optimization allows to reduce…

Accelerator Physics · Physics 2007-05-23 E. L. Saldin , E. A. Schneidmiller , M. V. Yurkov

To meet requirements of high performance THz-FEL (Free Electron Laser), a compact scheme of FEL injector was proposed. Thermionic cathode was chosen to emit electrons instead of photo-cathode with complex structure and high cost. The…

Accelerator Physics · Physics 2015-06-16 Tong-ning Hu , Qu-shan Chen , Yuan-ji Pei , Ji Li , Bin Qin

Autonomous methods to align beamlines can decrease the amount of time spent on diagnostics, and also uncover better global optima leading to better beam quality. The alignment of these beamlines is a high-dimensional, expensive-to-sample…

Free Electron Lasers (FEL) are commonly regarded as the potential key application of laser wakefield accelerators (LWFA). It has been found that electron bunches exiting from state-of-the-art LWFAs exhibit a normalized 6-dimensional beam…

This work proposes a hybrid modeling framework based on recurrent neural networks (RNNs) and the finite element (FE) method to approximate model discrepancies in time dependent, multi-fidelity problems, and use the trained hybrid models to…

Computational Engineering, Finance, and Science · Computer Science 2024-02-20 Moritz von Tresckow , Herbert De Gersem , Dimitrios Loukrezis

Automatic feature engineering is an effective approach for improving predictive performance in tabular learning. However, expand-and-reduce methods, such as OpenFE, become increasingly computationally expensive as the input dimensionality…

Machine Learning · Statistics 2026-05-01 Minhee Park , Seongyeon Son , Yonghyun Lee , Eunchan Kim

We analyze the dynamics of Free Electron Laser (FEL) devices, operating with a bunched beam exhibiting a longitudinal phase space correlation. We show that the presence of an energy-position correlation term is responsible for very…

Accelerator Physics · Physics 2010-11-08 G. Dattoli , L. Giannessi , P. L. Ottaviani , S. Pagnutti