-
Pardis Niknejadi (Deutsches Elektronen-Synchrotron DESY)24/08/2026, 16:00Session 5: Seeded FELPoster Presentation
Modern software systems increasingly require modular, reusable components that scales across diverse application domains. In accelerator physics, machines often rely on specialized simulation codes tailored to distinct segments of the accelerator, making integrated start-to-end studies complex and fragmented. Here, we introduce GEIST (Genesis–Elegant Interface Simulation Toolset), an...
Go to contribution page -
Primoz Rebernik Ribic (Elettra-Sincrotrone Trieste S.C.p.A.)24/08/2026, 16:00Session 5: Seeded FELPoster Presentation
With the completion of the early phase of the FERMI 2.0 upgrade program, the FERMI facility has significantly increased its flexibility, enabling the extension of its operational capabilities. The new FEL-1 layout, supporting both HGHG and EEHG, has substantially broadened the FEL-1 tuning range. This advancement is accompanied by improved spectral brightness and enhanced stability, achieved...
Go to contribution page -
Aaron Reed (SLAC National Accelerator Laboratory)24/08/2026, 16:00Session 3: FEL theory and Machine LearningPoster Presentation
At LCLS, attosecond xFEL pulses (“XLEAP” mode) allow users to probe electronic process on their natural timescale.* However, XLEAP is much more sensitive than conventional SASE operation to drifts and jitter in the RF phases, laser timing, bunch charge, and beam orbit. As a result, XLEAP setup and pulse energy optimization is highly variable and difficult to replicate even minute-to-minute,...
Go to contribution page -
Zihan Zhu (SLAC National Accelerator Laboratory)24/08/2026, 16:00Session 4: SASE FELPoster Presentation
We investigate attosecond spike formation in an x-ray free-electron laser driven by sign-reversing chirped undulator tapering. Time-dependent three-dimensional simulations with Athos-like soft-x-ray parameters reveal a characteristic evolution of the slice-resolved bunching across the taper reversal: localised bunching surviving before the reversal provides a coherent starting point for...
Go to contribution page -
David Cesar (SLAC National Accelerator Laboratory)24/08/2026, 16:00Session 8: Electron Beam DynamicsPoster Presentation
Attosecond FEL pulses can be generated by limiting lasing to a single high-current spike with a duration comparable to the FEL coherence length. At LCLS-II, the XLEAP program generates such a distribution by overlapping a short laser pulse onto the conventional cathode drive laser. Here, we demonstrate that this initial density perturbation drives a pair of counter-propagating space-charge...
Go to contribution page -
Yosuke Honda (High Energy Accelerator Research Organization)24/08/2026, 16:00Session 8: Electron Beam DynamicsPoster Presentation
Energy-Recovery Linac (ERL) based Free-Electron Laser (FEL) has been a promising solution for the high-power EUV light source for future semiconductor lithography. KEK has been developing the key components of the accelerator system and designing the prototype machine. Beam optics design is important for realizing the required beam performance in the FEL section, for safely transport the beam...
Go to contribution page -
Zihan Zhu (SLAC National Accelerator Laboratory)24/08/2026, 16:00Session 3: FEL theory and Machine LearningPoster Presentation
Control of the longitudinal phase space (LPS) of electron beams is essential for the flexible operation of X-ray free-electron lasers, but remains challenging because the measured beam distribution is high dimensional, noisy, and sensitive to machine drift. We develop and experimentally demonstrate a latent-space approach for online LPS shaping at the Linac Coherent Light Source.
Go to contribution page -
Nicholas Sudar (SLAC National Accelerator Laboratory)24/08/2026, 16:00Session 8: Electron Beam DynamicsPoster Presentation
The photon energy range of the LCLS-HE upgrade relies heavily on the achievable longitudinal beam brightness. The final peak current and correlated energy spread are both limited by the longitudinal phase space at the exit of the injector, non-linear compression, and collective effects. The initial charge distribution off the cathode effects all of these factors. However, determining an ideal...
Go to contribution page -
Wenxiang Hu (Paul Scherrer Institute)24/08/2026, 16:00Session 5: Seeded FELPoster Presentation
X-ray free electron lasers (XFELs) are modern photon sources which generate widely tuneable, high-brilliance, ultrafast laser pulses. External seeding schemes transfer the coherence properties of optical laser sources to the FEL pulses, while performing a photon energy upconversion. In this contribution, we show the latest external seeding results from the soft X-ray beamline at SwissFEL,...
Go to contribution page -
Ji Qiang (Lawrence Berkeley National Laboratory)24/08/2026, 16:00Session 8: Electron Beam DynamicsPoster Presentation
Lithography is a critical component of chip manufacturing in the semiconductor industry. The conventional laser-produced plasma (LPP) approach is energy-inefficient and poses potential environmental issues. In contrast, an energy recovery linac (ERL) based free-electron laser (FEL) offers a cleaner, more efficient alternative by recycling electron beam energy after FEL radiation. In this...
Go to contribution page -
Mikhail Krasilnikov (Deutsches Elektronen-Synchrotron DESY)24/08/2026, 16:00Session 4: SASE FELPoster Presentation
The Photo Injector Test Facility at DESY in Zeuthen (PITZ) is developing a THz free electron laser (FEL) as a potential source for pump–probe experiments at the European XFEL. In a recent proof-of-principle experiment using the LCLS-I undulator and a 17 MeV/c electron beam from the PITZ injector, pulse energies exceeding 100 μJ at 3 THz were demonstrated for bunch charges up to 2.4 nC. These...
Go to contribution page -
Chang-Kyu Sung (Pohang Accelerator Laboratory)24/08/2026, 16:00Session 4: SASE FELPoster Presentation
High-brightness free-electron laser (FEL) generation critically depends on both the transverse and longitudinal properties of the electron beam, such as transverse emittance, slice energy spread. These beam parameters can be significantly degraded due to collective effects, e.g., wakefield, coherent synchrotron radiation. Such effects are pronounced due to the high current spikes, so-called...
Go to contribution page -
Amir Weinberg (Tel Aviv University)24/08/2026, 16:00Session 3: FEL theory and Machine LearningPoster Presentation
Here we present an analytical model theory for time domain analysis and design of Tapering Enhanced Superradiant (TES) FEL at zero-slippage condition. The model is implemented for optimization of an ongoing experimental project of a THz radiation source based on the 6 MeV ORGAD RF-Accelerator at Ariel University.
The design of the setup is based on a twenty-period planar undulator made of...
Go to contribution page -
Jingyi Tang (Stanford University)24/08/2026, 16:00Session 3: FEL theory and Machine LearningPoster Presentation
We present a differentiable 1D free-electron laser (FEL) simulation framework based on automatic differentiation. In contrast to conventional FEL codes that provide only forward simulation, the differentiable formulation enables efficient evaluation of gradients of FEL observables with respect to beam, undulator, and model parameters. This makes it possible to apply gradient-based methods to...
Go to contribution page -
Ahmed Osman (SLAC National Accelerator Laboratory)24/08/2026, 16:00Session 8: Electron Beam DynamicsPoster Presentation
Laser heaters suppress microbunching instabilities in free-electron laser (FEL) injectors by increasing the uncorrelated slice energy spread. We investigate third-harmonic laser–undulator heating in the Linac Coherent Light Source-I (LCLS-I) injector and compare measurements of central slice energy spread versus laser pulse energy for fundamental and third-harmonic interactions. At moderate to...
Go to contribution page -
Trey Guest (European X-Ray Free-Electron Laser)24/08/2026, 16:00Session 8: Electron Beam DynamicsPoster Presentation
![Scheme for simultaneous MHz operation of beamline endstations based on electron and photon beam steering.][1]
The European XFEL comprises three SASE beamlines that branch to eight endstation instruments. Each beamline currently operates a single instrument exclusively, fundamentally limiting the total beamtime available for experiments. In this talk, we propose an electron beam steering...
Go to contribution page -
Dr Henry Freund (University of Maryland, College Park)24/08/2026, 16:00Session 4: SASE FELPoster Presentation
The Ming Xie* formula for shot noise has been widely used to estimate the performance of SASE free-electron lasers and has been compared with various simulation codes with great success. However, the formula is directly applicable only to a single slice of the electron beam and it would be useful to generalize the formula to treat arbitrary temporal bunch shapes. Ming’s formula applies...
Go to contribution page -
Arnav Swaroop (SLAC National Accelerator Laboratory, University of California, Berkeley)24/08/2026, 16:00Session 5: Seeded FELPoster Presentation
Coherent undulator radiation from pre-bunched electron beams can generate carrier-envelope phase (CEP) stable radiation pulses. Leveraging the development of multi-bunch concepts and pulse-by-pulse bunch shaping, we propose using CEP-stable coherent undulator radiation to seed the FEL instability and generate fully coherent phase-stable radiation pulses via double reflection. In this poster,...
Go to contribution page -
Chang-Kyu Sung (Pohang Accelerator Laboratory)24/08/2026, 16:00Session 5: Seeded FELPoster Presentation
We present the experimental results on the generation of fresh-slice self-seeded hard X-ray free-electron laser (FEL) pulses at PAL-XFEL. The self-seeding scheme significantly enhances the spectral brightness of FELs and has therefore been extensively verified and widely applied in user science over the years, whereas the fresh-slice technique enables higher pulse power by reducing the pulse...
Go to contribution page -
Alex DeSimone (Northern Illinois University)24/08/2026, 16:00Session 8: Electron Beam DynamicsPoster Presentation
We present a method that uses transverse wigglers to impart arbitrary correlations in transverse phase space. This approach becomes particularly powerful when combined with emittance exchange, which converts the transverse phase space into the longitudinal phase space. In contrast to conventional single-sinusoidal correlations, a sawtooth correlation can maximize the fraction of particles...
Go to contribution page -
Wenxiang Hu (Paul Scherrer Institute)24/08/2026, 16:00Session 5: Seeded FELPoster Presentation
First tunable, phase-locked, ultrafast hard X-ray (PHLUX) pulse pairs were generated at PAL-XFEL. A fresh-bunch self-seeded FEL, driven by an electron beam that was shaped with a slotted foil and a corrugated wakefield structure, generates coherent radiation that is intensity-modulated on the femtosecond time scale. We measure a stable frequency comb generated by a phase-locked pulse pair (to...
Go to contribution page -
Aliaksei Halavanau (SLAC National Accelerator Laboratory)24/08/2026, 16:00Session 4: SASE FELPoster Presentation
In recent years there is a growing interest in FEL-based generation of very soft x-rays, due to increased scientific and industrial applications. In this proceeding, we investigate the feasibility of very soft x-ray generation at the Linac Coherent Light Source (LCLS). We focus on the mechanisms of FEL tuning, diagnostics, and practical aspects of user delivery of such light. We demonstrate...
Go to contribution page -
Dr William Fawley (Lawrence Berkeley National Laboratory)24/08/2026, 16:00Session 3: FEL theory and Machine LearningPoster Presentation
The venerable GINGER code (first virtual light in 1985) has been extensively updated and extended with new features including an ADI-based Cartesian radiation field solver, a more robust, transversely-resolved, longitudinal space charge solver, and a new Python-based, GUI-oriented post-processor (XG3DpyPP). Serious efforts have been directed toward optimizing run times including support for...
Go to contribution page -
Dr Philipp Dijkstal (Paul Scherrer Institute)24/08/2026, 16:00Session 5: Seeded FELPoster Presentation
One goal of the recently proposed SwissFEL facility upgrade (SwissFELplus) is to enable the generation of longitudinally coherent FEL pulses across a large photon energy range at the the hard X-ray beamline Aramis. We consider to implement the Forward Bragg Diffraction self-seeding approach, where a diamond crystal in transmission geometry filters the SASE signal generated in the first...
Go to contribution page -
Ingmar Hartl (Deutsches Elektronen-Synchrotron DESY)24/08/2026, 16:00Session 5: Seeded FELPoster Presentation
We present recent progress on the SLASH laser system, a high-repetition-rate tunable femtosecond UV laser developed for external seeding of the FLASH free-electron laser (FEL). The system features a dual-branch architecture: a third-harmonic generation arm (343 nm) and a tunable OPCPA-based arm (297–317 nm), enabling flexible pulse control for advanced seeding schemes like echo-enabled...
Go to contribution page -
Zhangfeng Gao (Shanghai Synchrotron Radiation Facility)24/08/2026, 16:00Session 4: SASE FELPoster Presentation
Shanghai soft X-ray free electron laser facility(SXFEL) is the first coherent X-ray light source in China with a wavelength covering the water window. With the help of elliptically polarized undulators(EPU), the output laser can be switched between linear polarization and circular polarization, meeting the needs of different users. After tuning the planar undulators upstream and adjusting the...
Go to contribution page -
Jingyi Tang (Stanford University)24/08/2026, 16:00Session 8: Electron Beam DynamicsPoster Presentation
Digital twins and online physics models are becoming increasingly important for the operation of modern X-ray free-electron lasers, where high-brightness beam delivery depends on precise control of the longitudinal phase space. At LCLS and LCLS-II, small RF phase drifts in the early linac can produce large changes in bunch compression, causing discrepancies between offline model predictions...
Go to contribution page -
Amir Weinberg (Tel Aviv University)24/08/2026, 16:00Session 3: FEL theory and Machine LearningPoster Presentation
The 6MeV ORGAD Accelerator at Ariel University is driving a THz Superradiant FEL. The radiation is emitted superradiantly (in proportion to the number of electrons squared) in a rectangular waveguide-undulator section. The condition for the spontaneous emission to emit superradiantly is that the duration of the electron bunch σ_t is much shorter than the optical period (2π/ω) of the radiation...
Go to contribution page -
Samuel Sahel-Schackis (SLAC National Accelerator Laboratory, Stanford University)24/08/2026, 16:00Session 3: FEL theory and Machine LearningPoster Presentation
X-ray free-electron lasers enable femtosecond-resolution probing of photoinduced chemical dynamics. Interpreting these experiments requires atomistic simulations of excited-state systems on matching timescales - a task where ab initio molecular dynamics remains prohibitively expensive. We present a Neural Network Quantum Molecular Dynamics (NNQMD) framework that bridges this gap by training...
Go to contribution page -
Kookjin Moon (Pohang Accelerator Laboratory)24/08/2026, 16:00Session 5: Seeded FELPoster Presentation
Forward Bragg diffraction (FBD)-based hard X-ray self-seeding (HXRSS) is a promising method for producing narrow-bandwidth and stable hard X-ray FEL pulses. However, the pulse-energy stability of self-seeded FELs can be influenced by several temporal effects, including the FBD filter response, the electron bunch duration, the seed-pulse overlap, and the self-seeding chicane delay. In this...
Go to contribution page -
Naoto Yamamoto (High Energy Accelerator Research Organization)24/08/2026, 16:00Session 8: Electron Beam DynamicsPoster Presentation
Ions produced by collisions between high-energy electron beams and residual gas molecules can be trapped along the beam trajectory by the strong electric potential well of the electron beam, leading to detrimental effects on beam dynamics. Ion trapping is therefore a relevant issue for high-duty continuous-wave (CW) machines, such as energy recovery linacs intended for use as...
Go to contribution page -
Jack Hirschman (Stanford University)24/08/2026, 16:00Session 3: FEL theory and Machine LearningPoster Presentation
High-repetition-rate x-ray free-electron lasers operating at MHz rates generate data volumes that preclude offline analysis as a sole experimental strategy, demanding streaming diagnostics capable of real-time decision support. We present a hybrid neural architecture for online characterization of attosecond x-ray pulses from angular-streaking diagnostics* at LCLS-II, integrating...
Go to contribution page -
Svitozar Serkez (European X-Ray Free-Electron Laser)24/08/2026, 16:00Session 3: FEL theory and Machine LearningPoster Presentation
The radiation friction force acting on a relativistic electron in incoherent fields of spontaneous undulator radiation of other beam electrons moving in a spatially periodic magnetic field of the undulator is considered. An expression for the radiation friction force, both for the initial stage of the pre-Brownian motion of electrons and for the kinetic stage is obtained. Considering a helical...
Go to contribution page -
83. Representation learning for multi-projection beam images in simulated LCLS injector data (MOP17)Kiley Gruenberg (SLAC National Accelerator Laboratory)24/08/2026, 16:00Session 3: FEL theory and Machine LearningPoster Presentation
Machine-learning surrogate models for accelerators require compact beam representations that preserve physically meaningful structure while remaining useful for predictive and tuning tasks. In this work, multi-projection beam images from simulated LCLS injector data are studied as a representation-learning problem. The goal is to evaluate how ML model architecture choices impact the degree to...
Go to contribution page -
Matthias Scholz (Deutsches Elektronen-Synchrotron DESY)24/08/2026, 16:00Session 4: SASE FELPoster Presentation
Following the long installation and maintenance period in the second half of 2025, the European XFEL accelerator complex was successfully recommissioned and returned to user operation. During the shutdown, numerous modifications and upgrades were implemented across the accelerator and associated infrastructure, including improvements to the cryogenic system, the injector and the undulator...
Go to contribution page -
Seongyeol Kim (Pohang Accelerator Laboratory)24/08/2026, 16:00Session 3: FEL theory and Machine LearningPoster Presentation
Precise beam manipulation and preservation of beam quality along the beamline are essential to produce high-brightness X-ray Free Electron Lasers (XFELs). These tasks can be effectively carried out through accurate beam diagnostics. In addition, a calibrated simulation model enables investigation of the optimal beamline conditions against collective effects such as coherent synchrotron...
Go to contribution page -
Mikhail Krasilnikov (Deutsches Elektronen-Synchrotron DESY)24/08/2026, 16:00Session 4: SASE FELPoster Presentation
Development of a high-power, tunable THz source for pump–probe experiments at the European XFEL is currently underway at the Photo Injector Test Facility at DESY in Zeuthen (PITZ). With the present PITZ setup, FEL radiation in the 1–5 THz range can be generated using an LCLS-I undulator. Proof-of-principle experiment has been successfully demonstrated with high-charge electron beams of several...
Go to contribution page -
Hiroyuki Hama (Tohoku University)24/08/2026, 16:00Session 3: FEL theory and Machine LearningPoster Presentation
The Smith-Purcell effect is a well-known radiation emitted when an electron beam propagates the vicinity of a diffraction grating surface. Apparently, the surface current model* successfully interprets the process of Smith-Purcell radiation (SPR) generated through an Eshellet-type grating with a small blazing angle. According to the surface current model, the SPR intensity rapidly increases...
Go to contribution page -
Alex DeSimone (Northern Illinois University)24/08/2026, 16:00Session 8: Electron Beam DynamicsPoster Presentation
Transverse deflecting cavities (TDCs) have always been interesting beamline elements that couple a particle’s longitudinal position and transverse coordinates. While they have been widely adopted for longitudinal diagnostics and other specialized purposes, such as emittance exchange, several longitudinal manipulation methods using TDCs have been introduced during the last six years. These...
Go to contribution page -
David Dunning (Science and Technology Facilities Council)24/08/2026, 16:00Session 4: SASE FELPoster Presentation
UK scientists are amongst the leading users of XFELs, which enable revolutionary atomic-level imaging and ultrafast time resolution far beyond other methods. Looking to the future, the UK community have developed a science and technology case and a conceptual design for a next-generation XFEL. Such a facility will be able to leverage maturing technologies to deliver vast increases in research...
Go to contribution page
Choose timezone
Your profile timezone: