publications

peer-reviewed publications in reverse chronological order

51 peer-reviewed publications

2026

  1. Plasma Phys. Control. Fusion
    2026
    Evidence of electron microbunching in laser-driven modulated downramp injection and prospects for beam-driven implementation
    Chaojie Zhang, Audrey Farrell, Ken A. Marsh, and 2 more authors
    Summary: Reports the first experimental evidence of electron microbunching via modulated downramp injection in a laser wakefield accelerator and proposes a beam-driven scheme for FACET-II to generate attosecond, high-current beams.

2025

  1. Nat. Commun.
    2025
    Plasma-Wakefield Accelerator Simultaneously Boosts Electron Beam Energy and Brightness
    Chaojie Zhang, Douglas Storey, Alexander Knetsch, and 19 more authors
    Summary: Demonstrates that a plasma wakefield accelerator can act as a dual transformer to convert an input electron beam into a new one with much higher energy and brightness.

2024

  1. Phys. Rev. Lett.
    2024
    Bidirectional cascaded superfluorescent lasing in air enabled by resonant third harmonic photon exchange from nitrogen to argon
    Zan Nie, Noa Nambu, Kenneth A. Marsh, and 10 more authors
    Summary: Discovery of a new mechanism for cavity-free lasing in atmospheric air through third-harmonic photon mediated resonant energy transfer from nitrogen to argon, enabling bidirectional two-color cascaded superfluorescent lasing.
  2. Phys. Rev. Accel. Beams
    2024
    Wakefield generation in hydrogen and lithium plasmas at FACET-II: Diagnostics and first beam-plasma interaction results
    Doug Storey, Chaojie Zhang, Pablo San Miguel Claveria, and 29 more authors
    Summary: Experimental progress at FACET-II toward demonstrating high-gradient plasma wakefield acceleration with simultaneous high energy transfer efficiency and beam quality preservation, including advanced diagnostics and initial beam-plasma interaction results.
  3. Phys. Plasmas
    2024
    Thermal Weibel instability induced magnetic fields co-exist with linear wakes in laser-ionized plasmas
    Yipeng Wu, Audrey Farrell, Mitchell Sinclair, and 12 more authors
    Summary: Experimental and simulation study demonstrating coexistence of Weibel instability-induced magnetic fields and linear plasma wakes in laser-ionized plasmas, with implications for multi-bunch acceleration schemes.
  4. Plasma Phys. Control. Fusion
    2024
    Generation of meter-scale hydrogen plasmas and efficient, pump-depletion-limited wakefield excitation using 10 GeV electron bunches
    Chaojie Zhang, Doug Storey, Pablo San Miguel Claveria, and 26 more authors
    Summary: This paper demonstrates efficient wakefield excitation in meter-scale beam-ionized hydrogen plasmas at FACET-II.
  5. Nat. Commun.
    2024
    Plasma electron acceleration driven by a long-wave-infrared laser
    Rafal Zgadzaj, James Welch, Yuxuan Cao, and 20 more authors
    Summary: Demonstration of laser-driven plasma acceleration using a long-wave-infrared CO2 laser, achieving relativistic electron acceleration with sub-TW power and observing transition from self-modulation to bubble-regime acceleration.
  6. J. Plasma Phys.
    2024
    Correlations between X-rays, visible light and drive-beam energy loss observed in plasma wakefield acceleration experiments at FACET-II
    Chaojie Zhang, Doug Storey, Pablo San Miguel Claveria, and 26 more authors
    Summary: Experimental study documenting correlations between betatron X-ray signals, visible plasma light, and drive beam energy loss in plasma wakefield acceleration, demonstrating non-invasive diagnostics for energy transfer monitoring.
  7. Commun. Phys.
    2024
    Efficient generation and amplification of intense vortex and vector laser pulses via strongly-coupled stimulated Brillouin scattering in plasmas
    Yipeng Wu, Chaojie Zhang, Zan Nie, and 7 more authors
    Summary: Demonstrates strongly-coupled stimulated Brillouin scattering in plasmas as a promising amplification technique for vortex and vector laser pulses with up to 65% energy transfer efficiency, enabling all-optical polarization control and novel angular momentum couplings for plasma-based optical devices.

2023

  1. Rev. Mod. Plasma Phys.
    2023
    Self-organization of photoionized plasmas via kinetic instabilities
    Chaojie Zhang, Chen-Kang Huang, and Chan Joshi
    Summary: Comprehensive review of self-organization in strong-field photoionized, non-equilibrium plasmas through kinetic instabilities.
  2. Phys. Rev. Res.
    2023
    Efficient generation of tunable magnetic and optical vortices using plasmas
    Yipeng Wu, Xinlu Xu, Chaojie Zhang, and 8 more authors
    Summary: Demonstrates efficient generation of multimegagauss magnetic and tunable optical vortices through interaction of relativistic ionization fronts with Laguerre-Gaussian laser pulses, achieving up to 90% conversion efficiency and controllable topological charges via plasma density and orbital angular momentum manipulation.
  3. Phys. Rev. Accel. Beams
    2023
    Underdense plasma lens with a transverse density gradient
    Christopher E. Doss, Robert Ariniello, John R. Cary, and 17 more authors
    Summary: Presents theoretical model for transverse density gradients in underdense plasma lenses based on 3D particle-in-cell simulations, enabling analytical study of beam dynamics and estimation of witness electron bunch deflection for density uniformity tolerance studies in plasma accelerators.

2022

  1. Phys. Rev. Res.
    2022
    Highly spin-polarized multi-GeV electron beams generated by single-species plasma photocathodes
    Zan Nie, Fei Li, Felipe Morales, and 11 more authors
    Summary: Demonstrates generation of highly spin-polarized electron beams using single-species ytterbium plasma photocathodes, achieving 56% net spin polarization and 15 GeV acceleration in 41 cm through combined time-dependent Schrödinger equation and particle-in-cell simulations.
  2. Phys. Plasmas
    2022
    Electron Weibel instability induced magnetic fields in optical-field ionized plasmas
    Chaojie Zhang, Yipeng Wu, Mitchell Sinclair, and 14 more authors
    Summary: Presents comprehensive experimental and theoretical study of electron Weibel instability in optical-field ionized plasmas using time-resolved measurements with external electron probe bunches, extending previous work to both non-relativistic and quasi-relativistic regimes.
  3. PNAS
    2022
    Mapping the self-generated magnetic fields due to thermal Weibel instability
    Chaojie Zhang, Yipeng Wu, Mitchell Sinclair, and 15 more authors
    Summary: First experimental mapping of magnetic fields generated by thermal Weibel instability in laser-ionized plasmas.
  4. Opt. Express
    2022
    Cross-polarized common-path temporal interferometry for high-sensitivity strong-field ionization measurements
    Zan Nie, Noa Nambu, Kenneth A. Marsh, and 8 more authors
    Summary: Develops a highly sensitive cross-polarized common-path temporal interferometer with balanced detection achieving  0.6 mrad sensitivity for plasma density measurements, enabling comprehensive verification of strong-field ionization models across multiple regimes and gas types.

2021

  1. Phys. Rev. Lett.
    2021
    Extremely dense gamma-ray pulses in electron beam-multifoil collisions
    Archana Sampath, Xavier Davoine, Sebastien Corde, and 26 more authors
    Summary: Demonstrates that high-current ultrarelativistic electron beams interacting with multiple submicrometer-thick conducting foils undergo strong self-focusing with efficient gamma-ray synchrotron emission, achieving femtosecond collimated beams with number density exceeding that of a solid.
  2. Phys. Plasmas
    2021
    Ultra-short pulse generation from mid-IR to THz range using plasma wakes and relativistic ionization fronts
    Zan Nie, Yipeng Wu, Chaojie Zhang, and 6 more authors
    Summary: Demonstrates numerical and experimental techniques for generating ultra-short pulses covering 1-150 μm wavelength range using plasma wakes for frequency downshifting and relativistic ionization fronts for upshifting, enabling comprehensive coverage of the molecular fingerprint region.
  3. Plasma Phys. Control. Fusion
    2021
    Ionization induced plasma grating and its applications in strong-field ionization measurements
    Chaojie Zhang, Zan Nie, Yipeng Wu, and 4 more authors
    Summary: Novel technique using ionization-induced plasma gratings for absolute ionization degree measurements in strong-field physics.
  4. Nat. Phys.
    2021
    High-throughput injection–acceleration of electron bunches from a linear accelerator to a laser wakefield accelerator
    Yipeng Wu, Jianfei Hua, Zheng Zhou, and 13 more authors
    Summary: Demonstrates external injection from a conventional linear accelerator into a laser wakefield accelerator with nearly 100% coupling efficiency and subsequent acceleration without charge loss, representing a crucial step toward hybrid conventional-plasma-based accelerators.

2020

  1. Phys. Rev. Lett.
    2020
    Measurements of the growth and saturation of electron Weibel instability in optical-field ionized plasmas
    Chaojie Zhang, Jianfei Hua, Yipeng Wu, and 11 more authors
    Summary: Direct measurements of electron Weibel instability growth and saturation using femtosecond relativistic electron probes.
  2. Plasma Phys. Control. Fusion
    2020
    Probing thermal Weibel instability in optical-field-ionized plasmas using relativistic electron bunches
    Chaojie Zhang, Chen-Kang Huang, Ken A. Marsh, and 1 more author
    Summary: Proposes using ultrashort relativistic electron beams to probe the spatiotemporal evolution of self-generated magnetic fields in thermal Weibel instability, demonstrating how laser polarization controls magnetic field topology in optical-field-ionized plasmas.
  3. Plasma Phys. Control. Fusion
    2020
    Initializing anisotropic electron velocity distribution functions in optical-field ionized plasmas
    Chen-Kang Huang, Chaojie Zhang, Ken A. Marsh, and 2 more authors
    Summary: Demonstrates controlled generation of anisotropic electron velocity distributions in optical-field ionized helium plasmas through laser polarization control, enabling systematic study of plasma kinetic instabilities with Thomson scattering diagnostics.
  4. New J. Phys.
    2020
    Ion acceleration with an ultra-intense two-frequency laser tweezer
    Yang Wan, Igor A. Andriyash, Chi-Hao Pai, and 9 more authors
    Summary: Introduces a novel ultra-intense optical tweezer concept using two counter-propagating circularly polarized lasers of different frequencies to create controlled electron displacement and generate narrow-energy-spread ion beams from nano-foil targets with high efficiency.
  5. Nat. Commun.
    2020
    Photon deceleration in plasma wakes generates single-cycle relativistic tunable infrared pulses
    Zan Nie, Chi-Hao Pai, Jie Zhang, and 14 more authors
    Summary: Demonstrates experimental generation of high-power ( 100 GW) near single-cycle wavelength tunable (3–20 µm) infrared pulses using photon deceleration in laser-produced plasma wakes, enabling novel applications in relativistic nonlinear optics and molecular fingerprint spectroscopy.
  6. Commun. Phys.
    2020
    Conservation of angular momentum in second harmonic generation from under-dense plasmas
    Chen-Kang Huang, Chaojie Zhang, Zan Nie, and 3 more authors
    Summary: Verifies conservation of total angular momentum in photons through experimental measurement of helical phase in second harmonic radiation from underdense plasma, demonstrating conversion between spin and orbital angular momentum using Laguerre-Gaussian beams.

2019

  1. Sci. Adv.
    2019
    Ultrafast optical field-ionized gases—A laboratory platform for studying kinetic plasma instabilities
    Chaojie Zhang, Chen-Kang Huang, Ken A. Marsh, and 3 more authors
    Summary: Establishment of a laboratory framework for studying kinetic plasma instabilities using ultrafast optical field-ionized gases.
  2. Sci. Rep.
    2019
    High-resolution phase-contrast imaging of biological specimens using a stable betatron X-ray source in the multiple-exposure mode
    Bo Guo, Xiaohui Zhang, Jie Zhang, and 8 more authors
    Summary: First demonstration of high-resolution (5 μm) phase-contrast imaging using stable betatron X-ray source with <5% jitter in multiple-exposure mode, achieving biological imaging with modest 30-40 TW lasers for practical tabletop applications.
  3. Phys. Rev. Lett.
    2019
    Phase space dynamics of a plasma wakefield dechirper for energy spread reduction
    Yipeng Wu, Jianfei Hua, Zheng Zhou, and 12 more authors
    Summary: Demonstration of plasma wakefield dechirper achieving 10-fold reduction in electron beam energy spread from 1.28% to 0.13% FWHM, bringing plasma accelerator beam quality to levels needed for coherent light sources and colliders.
  4. Phys. Rev. Accel. Beams
    2019
    Effect of fluctuations in the down ramp plasma source profile on the emittance and current profile of the self-injected beam in a plasma wakefield accelerator
    Chaojie Zhang, Chen-Kang Huang, Ken A. Marsh, and 7 more authors
    Summary: Comprehensive 2D/3D PIC simulation study of down ramp injection for FACET-II, demonstrating ultra-low emittance beams ( 0.03 μm) and investigating the effects of ramp profile fluctuations on beam quality and current profiles.
  5. Phys. Rev. Appl.
    2019
    Near-ideal dechirper for plasma-based electron and positron acceleration using a hollow channel plasma
    Yipeng Wu, Jianfei Hua, Chi-Hao Pai, and 14 more authors
    Summary: Novel near-ideal dechirper concept using hollow channel plasma to reduce energy spread from few-percent to ≲0.1% without emittance growth, enabling applications to free-electron lasers and colliders through large-scale 3D PIC simulations.

2018

  1. Phys. Rev. E
    2018
    Physical mechanism of the electron-ion coupled transverse instability in laser pressure ion acceleration for different regimes
    Yang Wan, Chi-Hao Pai, Chaojie Zhang, and 7 more authors
    Summary: Extended one-dimensional two-fluid theory clarifying the physical mechanism of transverse instability in radiation pressure ion acceleration, demonstrating electron-ion coupling via ponderomotive force as the dominant instability source.
  2. Plasma Phys. Control. Fusion
    2018
    Probing plasma wakefields using electron bunches generated from a laser wakefield accelerator
    Chaojie Zhang, Yang Wan, Bo Guo, and 12 more authors
    Summary: Experimental demonstration of probing plasma wakefield structures using femtosecond relativistic electron bunches from laser wakefield accelerators, capturing wake evolution in density gradients and parallel wake structures.
  3. Plasma Phys. Control. Fusion
    2018
    Transverse phase space diagnostics for ionization injection in laser plasma acceleration using permanent magnetic quadrupoles
    Fei Li, Zan Nie, Yipeng Wu, and 14 more authors
    Summary: Development and application of permanent magnetic quadrupole-based transverse phase space diagnostics for characterizing ionization injection electron beams in laser plasma acceleration with high precision.
  4. Plasma Phys. Control. Fusion
    2018
    Phase locked multiple rings in the radiation pressure ion acceleration process
    Yang Wan, Jianfei Hua, Chi-Hao Pai, and 7 more authors
    Summary: Theoretical and simulation study revealing phase-locked double ring structures in ion phase space during radiation pressure acceleration, caused by ponderomotive trapping in moving standing waves from laser contrast effects.
  5. Plasma Phys. Control. Fusion
    2018
    On the feasibility of sub-100 nm rad emittance measurement in plasma accelerators using permanent magnetic quadrupoles
    Fei Li, Yipeng Wu, Zan Nie, and 14 more authors
    Summary: Systematic analysis of permanent magnetic quadrupole-based emittance measurement accuracy and reliability for sub-100 nm rad emittance beams from plasma accelerators, identifying key error sources and alignment requirements.
  6. Phys. Plasmas
    2018
    Tri-stage quasimonoenergetic proton acceleration from a multi-species thick target
    Yang Wan, Chi-Hao Pai, Jianfei Hua, and 7 more authors
    Summary: Novel tri-stage acceleration mechanism for generating quasimonoenergetic proton beams from multi-species thick targets, achieving 200 MeV protons with narrow energy spread suitable for medical applications using 100s TW lasers.
  7. Plasma Phys. Control. Fusion
    2018
    Evolution of plasma wakes in density up- and down-ramps
    Chaojie Zhang, Chan Joshi, Xinlu Xu, and 7 more authors
    Summary: Theoretical and simulation study of plasma wakefield evolution in non-uniform density profiles.
  8. Nat. Photon.
    2018
    Relativistic single-cycle tunable infrared pulses generated from a tailored plasma density structure
    Zan Nie, Chi-Hao Pai, Jianfei Hua, and 16 more authors
    Summary: Breakthrough demonstration of tunable relativistically intense single-cycle infrared pulses (5-14 μm) generated from tailored plasma density structures with 1.7% conversion efficiency and locked carrier-envelope phase for strong-field physics applications.

2017

  1. Phys. Rev. Lett.
    2017
    Femtosecond probing of plasma wakefields and observation of the plasma wake reversal using a relativistic electron bunch
    Chaojie Zhang, Jianfei Hua, Yang Wan, and 13 more authors
    Summary: First demonstration of femtosecond relativistic electron microscopy for visualizing plasma wakefields.

2016

  1. Sci. Rep.
    2016
    Capturing relativistic wakefield structures in plasmas using ultrashort high-energy electrons as a probe
    Chaojie Zhang, Jianfei Hua, Xinlu Xu, and 8 more authors
    Summary: Novel femtosecond electron probing method for visualizing relativistic plasma wakefields with unprecedented resolution.
  2. Phys. Rev. Lett.
    2016
    Physical mechanism of the transverse instability in radiation pressure ion acceleration
    Yang Wan, Chi-Hao Pai, Chaojie Zhang, and 8 more authors
    Summary: Theoretical model and 2D PIC simulations revealing the physical mechanism behind transverse instability in radiation pressure ion acceleration, analogous to oscillating two-stream instability in ICF research.
  3. Phys. Rev. Lett.
    2016
    Physics of phase space matching for staging plasma and traditional accelerator components using longitudinally tailored plasma profiles
    Xinlu Xu, Jianfei Hua, Yipeng Wu, and 10 more authors
    Summary: Novel approach using longitudinally tailored plasma density profiles to achieve phase space matching between plasma accelerator stages and traditional accelerator components with negligible emittance growth.
  4. Phys. Rev. Lett.
    2016
    Nanoscale electron bunching in laser-triggered ionization injection in plasma accelerators
    Xinlu Xu, Chi-Hao Pai, Chaojie Zhang, and 9 more authors
    Summary: Theoretical analysis and 3D simulations revealing nanoscale electron bunching in ionization injection due to phase-dependent tunneling ionization and nonlinear trapping dynamics, enabling coherent transition radiation generation.
  5. Phys. Rev. Accel. Beams
    2016
    Temporal characterization of ultrashort linearly chirped electron bunches generated from a laser wakefield accelerator
    Chaojie Zhang, Jianfei Hua, Yang Wan, and 10 more authors
    Summary: Development of optical deflecting cavity for sub-femtosecond resolution measurement of ultrashort electron bunches.
  6. Plasma Phys. Control. Fusion
    2016
    Low-energy-spread laser wakefield acceleration using ionization injection with a tightly focused laser in a mismatched plasma channel
    Fei Li, Chaojie Zhang, Yang Wan, and 8 more authors
    Summary: Improved ionization injection scheme using tightly focused laser in mismatched plasma channel achieving ultrashort electron bunches with narrow energy spread through shortened injection distance and envelope oscillation effects.
  7. Plasma Phys. Control. Fusion
    2016
    Colliding ionization injection in a plasma wakefield accelerator
    Yang Wan, Chaojie Zhang, Fei Li, and 8 more authors
    Summary: Novel scheme for generating high-quality electron bunches using counter-propagating laser pulse for ionization injection in beam-driven plasma wake with tunable injection distance and synchronized electron release.

2015

  1. Chin. Phys. C
    2015
    Generating 10–40 MeV high quality monoenergetic electron beams using a 5 TW 60 fs laser at Tsinghua University
    Jian-Fei Hua, Li-Xin Yan, Chih-Hao Pai, and 10 more authors
    Summary: Demonstration of high-quality monoenergetic electron beam generation using a compact 5 TW 60 fs laser system at Tsinghua University, achieving 10-40 MeV beams with excellent beam quality.

2014

  1. Phys. Rev. Lett.
    2014
    Phase-Space Dynamics of Ionization Injection in Plasma-Based Accelerators
    Xinlu Xu, Jianfei Hua, Fei Li, and 11 more authors
    Summary: Theoretical and simulation study revealing the complex phase-space evolution of electron beams in ionization injection, providing analytical framework for achieving ultralow emittance beams.
  2. Phys. Rev. ST Accel. Beams
    2014
    Low emittance electron beam generation from a laser wakefield accelerator using two laser pulses with different wavelengths
    Xinlu Xu, Yipeng Wu, Chaojie Zhang, and 8 more authors
    Summary: Novel two-color laser scheme separating wakefield excitation from injection process enables generation of ultralow emittance electron beams with more than one order of magnitude improvement.

2013

  1. Phys. Rev. Lett.
    2013
    Generating High-Brightness Electron Beams via Ionization Injection by Transverse Colliding Lasers in a Plasma Wakefield Accelerator
    Fei Li, Jianfei Hua, Xinlu Xu, and 10 more authors
    Summary: Novel ionization injection scheme using transverse colliding lasers produces ultra-bright electron beams with unprecedented low emittance in plasma wakefield accelerators.