Free-electron laser facilities demand versatile and inexpensive THz sources for pump-probe experiments. Smith-Purcell radiation provides a compact method to generate resonant and narrowband terahertz sources when relativistic electrons go through periodic dielectric grating structures, which are cost-efficient when fabricated by 3D printing. It has certain advantages over other available...
A laser pulse composed of a fundamental and an appropriately phased second harmonic can drive a time-dependent current of photoionized electrons that generates broadband THz radiation. Over the propagation distances relevant to many experiments, dispersion causes the relative phase between the harmonics to evolve. This “dephasing” slows the accumulation of THz energy and results in a...
We present experimental results from Helmholtz-Zentrum Dresden-Rossendorf of a THz Smith-Purcell Radiation source generated using Laser Wakefield Accelerator electron bunches. Affordable and small, aluminum-coated gratings were placed near accelerated electron bunches with an average energy and charge of 405 MeV and 467 pC to produce strong, coherent emission. The generated shots of radiation...
Multi-mJ terahertz (THz) radiation was generated in the process of laser wakefield acceleration (LWFA) when a gas jet was irradiated by 100-TW-class laser pulses [1]. The emitted THz radiation is radially polarized and broadband with an energy conversion efficiency of 0.15%. The amount of energy is orders of magnitude larger than expected from the coherent transition radiation (CTR) model, in...
Cyclotron Resonance Accelerator has several attractive features including: a compact robust room-temperature single-cell RF cavity as the accelerator structure; continuous high current accelerated dc beam output with self-scanning, obviating need for a separate beam scanner.
An electron accelerator version, electron Cyclotron Resonance Accelerator (eCRA) [1], is under the development to be...
The ongoing Plasma-driven Attosecond X-ray source experiment (PAX) at FACET-II aims to produce coherent soft X-ray pulses of attosecond duration using a Plasma Wakefield Accelerator [1]. These kinds of X-ray pulses can be used to study chemical processes where attosecond-scale electron motion is important. For this first stage of the experiment, PAX plans to demonstrate that <100 nm bunch...
The propagating density gradients of a plasma wakefield may be used to frequency upshift a trailing witness laser pulse, a process known as `photon acceleration'. Using a beam driver, shifts limited only by the particle beam energy are possible by finding appropriate phase-matching conditions with a tailored density gradient. The resulting extreme intensity XUV laser light demonstrated in...
Laser-driven free-electron lasers (LDFELs) replace magnetic undulators with the electromagnetic field of a laser pulse. Because the undulator period is half the wavelength of the laser pulse, LDFELs can amplify x rays to saturation using lower electron energies and over shorter interaction lengths than a conventional free-electron laser. Here we show that a flying-focus pulse substantially...
Extreme ultraviolet (XUV) light sources allow for the probing of bound electron dynamics on attosecond scales, interrogation of high-energy-density and warm dense matter, photolithography of nanometer-scale features, and access to novel regimes of strong-field quantum electrodynamics. Despite the importance of these applications, coherent XUV light sources remain relatively rare, and those...
Laser wakefield accelerator-driven betatron x-rays are bright, broadband synchrotron-like emission with micrometer-scale source size and sub-picosecond duration. Betatron x-rays provide a new avenue for high-resolution, high-throughput imaging of additively manufactured (AM) materials. AM alloys are commonly used in aerospace and automotive industries due to high strength and stiffness to...
We report on the achievements and challenges on high repetition rate lasers used as drivers for electron or proton acceleration. We recently demonstrated 700TW at 10Hz repetition, based on a new generation of high repetition rate pump lasers. This system under comissioning is expected to reach 2PW at 10Hz, opening the way to high flux GeV electron sources, or >100MeV proton sources. Moreover,...
Laser plasma accelerators are poised to reach electron energies of 10-100 GeV and this new regime will open novel applications such as the production of heavy particles including muons. Electrons with energies exceeding twice the rest mass of a muon (211 MeV/c2) can initiate muon generation through the Bethe-Heitler pair production process. This talk will present work on behalf of a...
Direct Laser Acceleration (DLA) of electrons is a mechanism for superponderomotive energy gain during relativistically intense laser-plasma interactions. As laser facilities reach multi-petawatt powers, DLA will be increasingly important as the main energy exchange mode between the laser and the plasma and create a route to generating high charge, highly-relativistic, broad-spectrum electron...
Direct laser acceleration (DLA) can generate superponderomotive energy electrons to hundreds of MeV, along with secondary particles and radiation, through the interaction of high-intensity picosecond laser pulses with underdense plasma. As a complex and dynamic process, the DLA electron acceleration can be affected by a number of factors, such as the laser focusing geometries [H Tang et al. ...
Recent progress in plasma-based accelerators has sparked intense interest in developing plasma-driven free-electron lasers [1]. However, operating free-electron lasers at soft and hard X-ray wavelengths necessitates electron beams with significantly enhanced 6D brightness. The author outlines comprehensive strategies for producing ultrahigh 6D brightness electron beams in beam-driven plasma...
Recent high repetition rate lasers capable to produce TW peak power, few-cycle laser pulses with 100 W average power at industrial standards. Hence, they may offer an alternative to the PW peak power lasers for applications that need a quasi-continuous source of neutrons.
The SEA laser of ELI-ALPS delivered 21 mJ, 12 fs laser pulses at 10 Hz repetition rate on the target. Deuterons were...
The ion channel laser (ICL) is similar to the free electron laser (FEL) but utilizes the electric field from a blowout regime plasma wake rather than the magnetic field from an undulator to oscillate particles. Compared to the FEL, the ICL can lase with much larger energy spread beams and in much shorter distances, making it an attractive candidate for a future compact plasma accelerator...
The generation of high-energy photons is a useful diagnostic tool in many different contexts. In laser-solid target experiments, the total yield and energy distribution can be compared for different target types to determine the optimal set-up for photon generation, to be used in radiography and computed tomography of dense objects. In colliding experiments between a laser pulse and an...
We are utilizing a sub-ps, sub-10 micron X-ray source for X-ray phase contrast imaging (XPCI) tomography of Inertial Confinement Fusion (ICF) fuel capsules). We will present results from an experiment in April 2024 at the Advanced Laser Light Source in Montreal, Canada. Radiography data was captured with Laser Wakefield Acceleration blowout regime betatron X-rays with a critical energy of...
An x-ray excitation in a medium can cause localized heating (<mK) and thermoelastic expansion, inducing a detectable ultrasonic emission which potentially enables low-dose, 3D imaging [1]. For effective ultrasonic emission, the dose should be deposited faster than the stress confinement time of the medium, ~ns for many applications. This modality has been studied in medical linear...