A5080208150- Particle Accelerators and Free-Electron Lasers
- Particle accelerators and beam dynamics
- Laser-Plasma Interactions and Diagnostics
- Gyrotron and Vacuum Electronics Research
- Advanced X-ray Imaging Techniques
- Superconducting Materials and Applications
- Laser-induced spectroscopy and plasma
- Laser Design and Applications
- Laser-Matter Interactions and Applications
- Terahertz technology and applications
- Plasma Diagnostics and Applications
- Atomic and Molecular Physics
- Magnetic confinement fusion research
- Electron and X-Ray Spectroscopy Techniques
- Muon and positron interactions and applications
- Advanced Electron Microscopy Techniques and Applications
- Chalcogenide Semiconductor Thin Films
- Crystallography and Radiation Phenomena
- Adaptive optics and wavefront sensing
- Photonic and Optical Devices
- Laser Material Processing Techniques
- Advanced Surface Polishing Techniques
- Advancements in Photolithography Techniques
- Pulsed Power Technology Applications
- Ion-surface interactions and analysis
Brookhaven National Laboratory
2015-2025
Brookhaven College
2024
University of California, Los Angeles
2010-2020
Particle Beam Lasers (United States)
2018
SLAC National Accelerator Laboratory
2016
Euclid Techlabs (United States)
2016
Office of Basic Energy Sciences
2016
Office of Science
2016
Argonne National Laboratory
2016
Tsinghua University
2016
We report the observation of a strong wakefield induced energy modulation in an energy-chirped electron bunch passing through dielectric-lined waveguide. This can be effectively converted into spatial forming microbunches with periodicity 0.5-1 ps and, hence, capable driving coherent terahertz radiation. The experimental results agree well theoretical predictions.
A strong energy modulation in an electron bunch passing through a dielectric-lined waveguide was recently demonstrated Antipov et al., Phys. Rev. Lett. 108, 144801 (2012). In this Letter, we demonstrate successful conversion of into beam density modulation, and the formation series microbunches with subpicosecond periodicity by means magnetic optics (chicane). coherent transition radiation signal produced is obtained tunability its carrier frequency 0.68--0.9 THz range regulating chirp...
Current filamentation instability is observed and studied in a laboratory environment with 60 MeV electron beam plasma capillary discharge. Multiple filaments are imaged transversely at the exit optical transition radiation. By varying density between single multiple found to be ${k}_{p}{\ensuremath{\sigma}}_{r}\ensuremath{\sim}2.2$. Scaling of transverse filament size skin depth predicted theory over range densities. Lowering bunch charge, thus density, suppresses instability.
We report the observation of coherent Cerenkov radiation in terahertz regime emitted by a relativistic electron pulse train passing through dielectric lined cylindrical waveguide. describe beam manipulations and measurements involved repetitive creation including comb collimation nonlinear optics corrections. With this technique, modes beyond fundamental are selectively excited use appropriate frequency train. The spectral characterization structure shows preferential excitation higher...
A tunable energy-chirp compensator was used to remove a correlated energy chirp from the 60-MeV beam at Brookhaven National Laboratory Accelerator Test Facility. The operates through interaction of wakefield electron bunch with itself and consists planar structure comprised two alumina bars copper-plated backs separated by an adjustable aperture. By changing gap size, completely removed. Calculations show that this device, properly scaled account for charge length, can be residual spread end...
Abstract A compact collinear wakefield accelerator has been designed for an X-ray free-electron laser capable of operating at a pulse repetition rate in the tens kilohertz. The maximum achievable accelerating gradient determined, with its limitation linked to beam breakup instability. fabrication techniques principal components including generation, couplers excess power extraction and diagnostics, focusing quadrupoles, novel undulator have discussed. Results from various laboratory...
Magnetism in two-dimensional (2D) van der Waals (vdW) crystals offers promising new directions for low-dimensional physics and devices. In this work, mega-electron volt (MeV) ultrafast electron diffraction was employed to investigate the atomic dynamics of a novel, 2D vdW magnetic single-crystal CrSBr. Femtosecond (fs) optical pump pulses excited non-equilibrium displacements shown be coherent acoustic phonons (CAPs). Phonon frequencies were extracted by analyzing oscillations different...
We report first evidence of wakefield acceleration a relativistic electron beam in dielectric-lined slab-symmetric structure. The high energy tail $\ensuremath{\sim}60\text{ }\text{ }\mathrm{MeV}$ was accelerated by $\ensuremath{\sim}150\text{ }\mathrm{keV}$ 2 cm-long, ${\mathrm{SiO}}_{2}$ waveguide, with the or deceleration clearly visible due to use bifurcated longitudinal distribution that serves approximate driver-witness pair. This split-bunch is verified reconstruction analysis emitted...
We have directly measured THz wakefields induced by a subpicosecond, intense relativistic electron bunch in diamond loaded accelerating structure via the wakefield acceleration method. present here beam test results from based structure. Diamond has been chosen for its high breakdown threshold and unique thermoconductive properties. Fields produced leading (drive) were used to accelerate trailing (witness) bunch, which followed drive at variable distance. The energy gain of witness as...
Inverse Compton scattering of laser photons by ultrarelativistic electron beam provides polarized x- to $\ensuremath{\gamma}$-ray pulses due the Doppler blueshifting. Nonlinear electrodynamics in relativistically intense linearly field changes radiation kinetics established during interaction. These are induced figure-8 motion, which introduces an overall redshift spectrum, with concomitant emission higher order harmonics. To experimentally analyze strong physics associated nonlinear...
We demonstrate experimentally that a relativistic electron bunch shaped with sharp rising edge drives plasma wakefields one to seven periods along the as density is increased. The varied in 10(15)-10(17) cm(-3) range. generation observed after periodic modulation of correlated energy spectrum incoming bunch. choose low charge 50 pC for optimum visibility at all densities. longitudinal creating are MV/m range and indirect evidence transverse can seed self-modulation instability, although...
We have measured an intense THz radiation produced by a sub-picosecond, relativistic electron bunch in dielectric loaded waveguide. For efficient pulse extraction, the waveguide end was cut at angle. appropriate choice of angle cut, such antenna converts TM01 mode excited into free-space fundamental Gauss-Hermite propagating with respect to beam trajectory. Simulations show that more than 95% energy can be extracted using simple approach. More 40 oscillations about 170 ps long 0.48 signal...
Abstract Laser-driven plasma accelerators provide tabletop sources of relativistic electron bunches and femtosecond x-ray pulses, but usually require petawatt-class solid-state-laser pulses wavelength λ L ~ 1 μ m. Longer- lasers can potentially accelerate higher-quality bunches, since they less power to drive larger wakes in dense plasma. Here, we report on a self-injecting accelerator driven by long-wave-infrared laser: chirped-pulse-amplified CO 2 laser ( ≈ 10 m). Through optical...
We present results of an experiment where, using a 200 GW CO2 laser seed, 65 MeV electron beam was decelerated down to 35 in 54 cm long strongly tapered helical magnetic undulator, extracting over 30$\%$ the initial energy coherent radiation. These demonstrate unparalleled electro-optical conversion efficiencies for relativistic undulator field and represent important step development high peak average power radiation sources.
Photonic structures operating in the terahertz (THz) spectral region enable essential characteristics of confinement, modal control, and electric field shielding for very high gradient accelerators based on wakefields dielectrics. We report here an experimental investigation THz wakefield modes a three-dimensional photonic woodpile structure. Selective control exciting or suppressing with nonzero transverse wave vector is demonstrated by using drive beams varying ellipticity. Additionally,...
Temporal pulse tailoring of charged-particle beams is essential to optimize efficiency in collinear wakefield acceleration schemes. In this Letter, we demonstrate a novel phase space manipulation method that employs beam interaction dielectric structure, followed by bunch compression permanent magnet chicane, longitudinally tailor the shape an electron beam. This compact, passive, approach was used generate nearly linearly ramped current profile relativistic experiment carried out at...
We report experimental measurements of narrow-band, single-mode excitation, and drive beam energy modulation, in a dielectric wakefield accelerating structure with planar geometry Bragg-reflector boundaries. A short, relativistic electron ($\ensuremath{\sim}1\text{ }\text{ }\mathrm{ps}$) moderate charge ($\ensuremath{\sim}100\text{ }\mathrm{pC}$) is used to the wakefields structure. The fundamental mode reinforced by constructive interference alternating layers at boundary, characterized...
Significant progress has been made at Argonne National Laboratory in the development of a compact wakefield accelerator based on cylindrical corrugated waveguide with 2-mm ID and fine corrugations wall. The fabrication process 10-cm-long structures established high quality final product confirmed by precision metrology. Several samples have tested using electron beam Brookhaven Laboratory's Accelerator Test Facility. frequency group velocity fundamental monopole ${\mathrm{TM}}_{01}$ mode...
Photoinduced ultrafast phase transitions can generate quasiequilibrium states with novel emergent properties modulated by the interplay of electronic and lattice degrees freedoms. Therefore, accurately probing transient atomic structures their dynamics is crucial to understand control interaction electrons but remains a central challenge science. Using MeV electron diffraction on single crystals, we quantitatively reveal photoinduced distortion monoclinic M1 VO2. Our results resolve previous...
The generation of X-rays and γ-rays based on synchrotron radiation from free electrons, emitted in magnet arrays such as undulators, forms the basis much modern X-ray science. This approach has drawback requiring very high energy, up to multi-GeV-scale, electron beams, obtain required photon energy. Due limit accelerating gradients conventional particle accelerators, reaching energy typically demands use instruments exceeding 100's meters length. Compact, less costly, monochromatic sources...
Inverse Compton Scattering (ICS) is an emerging compact X-ray source technology, where the small size and high spectral brightness are of interest for multitude applications. However, to satisfy practical flux requirements, a high-repetition-rate ICS system needs be developed. To this end, paper reports experimental demonstration peak operating in burst mode at 40 MHz. A pulse train interaction has been achieved by recirculating picosecond CO2 laser inside active optical cavity synchronized...
We present results of an experiment showing the first successful demonstration a cascaded micro-bunching scheme. Two modulator-chicane pre-bunchers arranged in series and high power mid-IR laser seed are used to modulate 52 MeV electron beam into train sharp microbunches phase-locked external drive laser. This configuration allows increase fraction electrons trapped strongly tapered inverse free (IFEL) undulator 96\%, with up 78\% particles accelerated final design energy yielding...