To optimize proton maximum energy, we adjusted the deformable mirrorโs actuators, which directly influence the laser spot size and shape (measured by a wavefront analyzer). Starting with all voltages set to 0V, we aimed to find the optimal configuration to maximize proton energy. Utilizing the ALLS 150 TW laserโs high-repetition rate and a multi-target holder, we collected a dataset of...
Recent developments in relativistic LaguerreโGaussian (LG) lasers have sparked physical research into petawatt (PW) laser facilities. It has been observed that LG lasers not only produce hollow laser intensity but also generate novel structured electric fields for different LG modes. In the case of left circularly polarized LG lasers, the longitudinal electric field, combined with the hollow...
This contribution will present recent progress and limitations of the electron acceleration program at CALA. We are working on several programmatic goals:
1. providing monoenergetic multi-GeV beams for our planned Breit-Wheeler experiment.
2. expanding the hybrid LWFA-PWFA scheme towards ultra-low emittance and high transformer ratios, while characterizing the hybrid LWFA-PWFA plasma wave...
Laser plasma-based ion accelerators have not yet reached their full potential in producing high radiation doses at high particle energies, mainly due to the lack of a suitable high-repetition-rate targets that also provide adequate control of the plasma conditions. Cryogenic, solid gas jet targets are being developed to fill this gap, as they combine many favourable properties for studying...
We present an in-depth analysis of Laser Wakefield Acceleration (LWFA) experiments performed at the ATLAS-3000 system at CALA in Garching, achieving GeV-scale electron energies with a slit-nozzle target. Through simultaneous monitoring of laser and electron diagnostics for about 2000 shots performed at a 0.25 Hz repetition rate, we identify the laser wavefront as the primary factor influencing...
The acceleration of heavy ions with mass number of ~200-class by high intensity femtosecond laser pulse is still challenging because of the too small knowledge of the ionization mechanisms which strongly couple to the dynamics of the plasma and determine the acceleration efficiency especially at the relativistically induced transparency (RIT) phase where efficient acceleration takes place. The...
Most of the previous studies [1,2,3] on laser-driven proton-boron nuclear reactions are based on the measurement of ฮฑ-particles with Solid-State Nuclear Track Detectors (CR-39). However, the interpretation of CR-39 results is difficult due to the presence of several other accelerated particles, which can bias the analysis [4]. Furthermore, in some laser irradiation geometries, cross-checking...
We describe recent results from our programme to develop high-repetition-rate, GeV-scale plasma-modulated plasma accelerators (P-MoPAs), which seeks to take advantage of advanced thin-disk lasers (TDLs) that can deliver joule-scale, picosecond-duration pulses, at kHz repetition rates.
A P-MoPA has three stages: (i) a modulator, in which a TDL pulse is guided in a hydrodynamic...
Ion acceleration via compact laser-plasma sources holds great potential for applications from radiation therapy research to fusion research. Achieving the desired beam quality requires a deep understanding and precise control of laser-plasma interactions. Our collaborative research at the DRACO PW (HZDR) and J-KAREN-P (KPSI) laser systems investigates the promising regime of Relativistically...
Hybrid laser and electron beam-driven plasma accelerators (L-PWFA) have been a growing focus in recent years, combining the strengths of laser wakefield acceleration (LWFA) and particle beam-driven plasma wakefield acceleration (PWFA). In this approach, an LWFA stage generates a high-current electron bunch, which drives a subsequent PWFA stage where a witness bunch is internally injected and...
The Compact Linear Accelerator for Research and Applications (CLARA) at Daresbury Laboratory in the UK is a state-of-the-art facility that provides mid-energy range, high-brightness electron beams for exploring innovative concepts in accelerator science and technology. An exciting upcoming development is the integration of the Full Energy Beam Exploitation (FEBE) beamline, specifically...
Helical coil targets [1] are commonly used to focus, collimate, bunch, and accelerate protons via the Target Normal Sheath Acceleration (TNSA) process, producing highly focused and collimated beams [2]. However, acceleration and bunching remain limited by current dispersion along the helix. To overcome this, we introduced a tube around the helix, reducing dispersion and enhancing bunching [3]....
Laser-wakefield acceleration (LWFA) of electrons at a kHz repetition rate holds significant promise for medical and industrial applications. Until recently, kHz laser systems have been limited to few-mJ pulses, necessitating sharp focusing and strong temporal compression to achieve relativistic intensities [Guรฉnot 2017]. Continuous operation of a kHz laser-plasma accelerator requires...
Laser-plasma acceleration (LPA) generates ion beams with extraordinary properties. The inherently high number of accelerated ions, delivered in ultrashort bunches, makes LPA ion sources ideal for high-dose-rate applications such as radiobiology. However, these bunches exhibit high divergence and broad energy spectra, necessitating spatial and spectral shaping before utilization.
To address...
Our group has developed a laser wakefield accelerator (LWFA) based on a near-single-cycle laser driver, producing up to 10 MeV electron beams at kHz repetition rates [1]. For near-single-cycle laser pulses, the ponderomotive approximation breaks down and the plasma response becomes sensitive to the waveform of the laser field so that the carrier-envelope phase (CEP) can affect electron...
In the peeler scheme the laser pulse is incident on the narrow edge of a tape-like target. The generated surface plasma wave accelerates the electrons peeled from the lateral surface of the target, thus generating an high-charge electron bunch that creates a large amplitude accelerating field for positive ions residing the in the target rear, allowing for the generation of quasi-mochromatic...
Laser-driven ion accelerators offer multi-MeV beams with high-peak currents, enabling applications in radiotherapy, neutron generation, and fast ignition in inertial confinement fusion. However, transitioning from complex experiments to reliable particle sources requires advances in beam quality, robustness, and high-repetition-rate scalability.
Recent studies have identified the...
Plasma photocathodes, also known as Trojan Horse injectors, utilise a comparatively low-intensity laser pulse to ionise and release electrons at defined locations directly inside a plasma wakefield. Provided a sufficiently strong wakefield, these electrons are initially compressed, trapped and subsequently accelerated. The trapped bunch characteristics are thereby largely determined by the...
High radiation environments are present in many fields, such as fusion facilities, nuclear reactors, high-luminosity accelerators, space and defense sector. The employed materials, e.g. plasma facing materials, and devices, e.g. Commercial Off-The-Shelf (COTS) semiconductor components, need to withstand excessive stressful radiation levels. Quick and adequate qualification tests against...
We report self-injecting LWFA driven by CPA-CO2 laser pulses of wavelength ~10 micrometers at Brookhaven's Accelerator Test Facility [1]. Long-wave IR pulses open opportunities to drive large wakes in low-density plasma more efficiently than near-IR pulses, potentially enabling higher-quality accelerated bunches. In experiments, 0.5-TW, 4-ps laser pulses generated no electrons, but drove...
Laser-driven electron acceleration schemes can be easily and reliably used to accelerate electrons in the energy band between 20ย MeV and 200 MeV, termed Very-High Energy electrons (VHEE) in medical physics. Such radiation quality is regarded as a candidate for novel radiation therapy schemes, owing to a favorable depth-dose deposition profile and the possibility of reaching very-high...
Axion and axion-like particle are the candidates of dark matter. In the current theoretical frame, they can couple with the electromagetic fields and convert to photons and vice versa. We proprosed a scheme to generate axions in a plasma bubble structure driven by two intense laser pulses. One pulse drives a nonlinear bubble wake in a plasma and the other propagates inside the bubble. The...
We present the results achieved during the commissioning of the ELI Gammatron beamline, a femtosecond hard X-ray betatron source based on laser wakefield acceleration driven by the petawatt-class L3 laser system (10 J, 27 fs, 3.3 Hz) at ELI Beamlines. Leveraging the small pointing and energy fluctuations of the laser system, we have successfully demonstrated laser wakefield acceleration of...
We developed a laser-driven Particle Induced X-ray Emission (laser-PIXE) system utilizing compact and high-intensity particle sources to achieve rapid real-time elemental analysis of aerosols. Conventional PIXE techniques rely on large accelerators, limiting their use in on-site and real-time applications. Our study addresses this limitation by leveraging advancements in laser-driven particle...
When an electron bunch passes through a conducting foil, its self-fields are reflected at the foil surface, also known as Near-Field Coherent Transition Radiation (NF-CTR) resulting in a focusing effect for the electron beam. Passing through multiple foils may allow to focus the electron beam down to solid densities and generate collimated gamma-rays with micrometer source sizes and conversion...
Laser-plasma accelerators now regularly achieve GeV electron energies in laboratory-scale facilities, enabling new research opportunities. One significant application is the generation of ultrashort (few femtoseconds) X-rays through betatron electron oscillations. These broadband pulses are ideal for X-ray absorption spectroscopy (XAS), particularly XANES (X-ray Absorption Near Edge Structure)...
For over twenty years high harmonic generation from the interaction between a relativistic laser pulse and solid target (SHHG) has been heralded as a realistic route to the Schwinger limit, the electromagnetic field intensity at which SF-QED effects can be probed in vacuum. Despite extensive simulation campaigns and the development of theoretical models of increasing sophistication,...
Accurate representation of electromagnetic wave packets in particle-in-cell simulations is crucial for ensuring that the outcomes closely align with experimental results. Conventional methods for laser injection rely on the paraxial and envelope approximations, effective for beams that are both long and wide with respect to the laser's wavelength. However, new laser systems are advancing...
Energy gain in laser wakefield accelerators is limited by dephasing, and the resulting electron beams often exhibit high divergence, posing challenges for transport and applications. We experimentally demonstrate that tailoring the plasma density profile can mitigate both limitations. Using shock-assisted ionization injection, we generate quasi-monoenergetic 100 MeV electron bunches. A...
Various laser-plasma experiments, including those in laboratory astrophysics, particle acceleration, plasma physics, and X-ray generation, require advanced gas target technologyโa system capable of delivering gas with a precisely defined density profile within a high-vacuum environment. The performance of particle beams and radiation in these experiments is highly sensitive to the optimal...
Exascale simulation capabalities are now available for studying laser plasma accelerators using realistic laser and plasma descriptions and providing quantitative predictions. We present recent advances in modeling LPA at large scales for both electron and ion acceleration. We specifically discuss workflows for comparison to experiments and evaluate predictive capabilities. The role of...
At DESY, we are developing KALDERA, a high-repetition-rate laser system designed to enable active stabilization of laser-plasma acceleration through fast feedback systems. A critical step in this process is accurately measuring how variations in laser parameters affect the electron beam properties, with particular emphasis on the wavefront due to its significant influence on the acceleration...
New laser facilities will reach intensities of 1023 Wcmโ2. In these setups with extreme ๏ฌelds, quantum electrodynamic (QED) e๏ฌects become important. We study high-intensity lasers grazing the surface of a solid-state target by two-dimensional particle-in-cell simulations with QED e๏ฌects included. The two laser beams collide at the target surface at a grazing angle. Due to the ๏ฌelds near the...
This presentation summarizes recent progress made by the HZDR-Soleil collaboration on seeded free-electron-laser performance with the COXINEL line operated at HZDR's laser plasma electron accelerator.
Following the first demonstration of lasing [1], tuning range and output spectrum were studied [2], while a careful analysis of the shape of the interference pattern of seed and FEL light...
The emergence of high-power laser systems approaching kilohertz repetition rates presents both a challenge and an opportunity for the next generation of laser-plasma accelerators (LPAs). The vast amount of data generated at these high repetition rates opens the door to novel, data-driven approaches for improving stability, beam quality, and reliabilityโcritical steps toward making LPAs viable...
In order to reach higher energies, next generation plasma accelerators will use multi-meter plasma technology. Many applications will also require high repetition rates to obtain high average fluxes comparable to conventional radiofrequency accelerators. These long-scale plasmas are not trivial to produce due to the very high power requirements for gas ionisation.
We present the...
Quasistatic particle-in-cell (QSPIC) codes[1] are increasingly used to study laser or plasma wakefield accelerators. QSPIC codes decouple the slow evolution of a beam from the fast response of a plasma, which reduces the computational cost by several orders of magnitude compared with conventional PIC codes. In this presentation, we demonstrate the potential of the QSPIC method to investigate...
We report the design and performance of a compact magnetic spectrometer tailored to unique characteristics of quasi-monoenergetic, multi-GeV electron bunches from petawatt-laser-driven wakefield accelerators: mrad-level shot-to-shot pointing fluctuations, co-generation of betatron X-rays and of background electrons with a broad energy spectrum. The spectrometer replaces the first screen of a...
We discuss generation and acceleration of muon beams in the 500 GeV - 1 TeV energy range via staged plasma accelerators, in view of a relevant example concerning geological investigations, with request on beam intensity and phase space quality very adapt to a pilot experiment with a hybrid plasma accelerator ร la EupraXia@LNF. Unlike muon beams for muon colliders, the applications foreseen in...
The laser-plasma accelerator-based Free Electron Laser development program at ELI-ERIC (ELI Beamlines, Czech Republic) aims to utilize the unique properties of plasma accelerators to create compact FELs with exceptional performance regarding brightness, coherence, and pulse duration. The program is based on the advanced high-power, high-repetition-rate L2-DUHA laser system developed at ELI...
During recent years DESY has strengthened its effort to evolve laser plasma acceleration technology from demonstration experiments towards reliably running machines. In this framework we develop the Ti:Sapphire based drive-laser KALDERA which is supposed to deliver up to kHz repetition rates at more than 100 TW of peak power in its final phase. Since current drive-lasers operate at the low...
Laser-plasma acceleration (LPA) is a promising technology for future compact accelerators. However, the low repetition rate (typically few Hz) of todayโs high-power laser systems prevents reaching the average power required by applications and hinders the implementation of fast feedback systems to mitigate beam instabilities. To this end, DESY has established a dedicated research program on...
The Zettawatt Equivalent Ultrashort Pulse Laser System (ZEUS) is a user facility funded by the National Science Foundation and located at the University of Michigan in the US. ZEUS consists of a repetitive dual-beamline 3 PW laser system, a programmable multi-nanosecond pulse driver capable of delivering 100 J of energy, and three experimental areas with radiation shielding. It offers unique...
The 100 TW DPSSL-OPCPA L2-DUHA laser system is under development at ELI-ERIC, with the goal of being the driver for the Laser Plasma Accelerator (LPA) of the LUIS-beamline, an incoherent Extreme Ultraviolet (EUV) radiation setup under development at ELI-ERIC, aiming to produce the high-quality electron beam required for a LPA-based Free Electron Laser (FEL).
The L2-DUHA broadband front-end...
The time for stationary plasma to recover its original state after a wake is excited determines repetition rate and luminosity of plasma-based colliders. Recent measurements at DESY [1] showed that an argon plasma of density neโ$10^{16}$cm$^{โ3}$ in which a 0.5J(0.5nC,1GeV) e-bunch excited a first wake supported excitation of a second wake at the same location with indistinguishable beam...
Precise synchronization plays a major role in the stability of an accelerator-based light source, or for ultrafast dynamics studies. We will present our strategy and recent achievements applied to synchronize a kHz Ti:Sa ultrafast laser to a Terawatt Yb ultrafast laser. We report on the synchronization at few fs rms level, both on short-term and long-term.
We first synchronize the slave...
There is a growing interest of using Laser Plasma Acceleration (LPA) for societal applications provided that particle flux is large enough to fulfill the needs of those applications. This calls for the use of lasers with higher pulse repetition rate than the lasers used up to now in laser plasma acceleration research. In this talk, we present the achievements and the technology roadmap related...
Particle acceleration in plasmas relies on characterization of the medium's density and temperature, determining key plasma parameters (such as plasma frequency, Debye length, Debye number, and coupling parameter) that must be carefully controlled for efficient acceleration.The plasma production in these applications vary, and as a result, the diagnostic techniques used to characterize them...
