Publishing technical papers in the refereed literature and making presentations at conferences and workshops are among the vital ways in which our researchers communicate their results. In general, the corresponding or principal author is listed first. Indicating the broad collaborative nature of our work, some entries (noted in italics) have a corresponding author outside LBNL.
2022
Fedeli L, Huebl A, Boillod-Cerneux F, Clark T, Gott K, Hillairet C, Jaure S, Leblanc A, Lehe R, Myers A, Piechurski C, Sato M, Zaim N, Zhang W, Vay J-L, Vincenti H. Pushing the Frontier in the Design of Laser-Based Electron Accelerators with Groundbreaking Mesh-Refined Particle-In-Cell Simulations on Exascale-Class Supercomputers. SC22: International Conference for High Performance Computing, Networking, Storage and Analysis (SC). ISSN:2167-4337, pp. 25-36, Dallas, TX, US, 2022. DOI:10.1109/SC41404.2022
2021
J.-L. Vay, A. Huebl, A. Almgren, L.D. Amorim, J. Bell (LBNL); L. Fedeli (CEA Saclay); L. Ge (SLAC); K. Gott (LBNL); D.P. Grote (LLNL); M. Hogan (SLAC); R. Jambunathan, R. Lehe, A. Myers (LBNL); C. Ng (SLAC); M. Rowan, O. Shapoval (LBNL); M. Thévenet (DESY); H. Vincenti (CEA Saclay); E. Yang (LBNL); N. Zaïm (CEA Saclay); W. Zhang, Y. Zhao, and E. Zoni (LBNL), “Modeling of a chain of three plasma accelerator stages with the WarpX electromagnetic PIC code on GPUs,” Physics of Plasmas 28, 2, 10.1063/5.0028512, Special Collection: Building the Bridge to Exascale Computing: Applications and Opportunities for Plasma Science (9 February 2021), https://doi.org/10.1063/5.0028512
2020
Felice Albert et al., including A. Huebl and J.-L. Vay (LBNL), “2020 Roadmap on Plasma Accelerators,” New Journal of Physics, in press December 2020, https://doi.org/10.1088/1367-2630/abcc62
Francis Alexander et al., incl. Jean-Luc Vay (LBNL), “Exascale applications: skin in the game,” Philosophical Transactions of the Royal Society A 378, 20190056 (20 January 2020), http://dx.doi.org/10.1098/rsta.2019.0056
A. Huebl et al., “Spectral Control via Multi-Species Effects in PW-Class Laser-Ion Acceleration”, Plasma Physics and Controlled Fusion 62, 124003 (29 October 2020), https://doi.org/10.1088/1361-6587/abbe33
Biaobin Li (National Synchrotron Radiation Laboratory, University of Science and Technology of China, and LBNL) and Ji Qiang (LBNL), “Mitigation of microbunching instability in x-ray free electron laser linacs,” Physical Review Accelerators and Beams 23, 014403 (9 January 2020), https://doi.org/10.1103/PhysRevAccelBeams.23.014403
Robert D. Ryne, “Muon colliders come a step closer,” Nature News and Views, https://www.nature.com/articles/d41586-020-00212-3, a companion article to MICE Collaboration, incl. A. DeMello, S. Gourlay, A. Lambert, D. Li, T. Luo, S. Prestemon, and S. Virostek (LBNL), “Demonstration of cooling by the Muon Ionization Cooling Experiment,” Nature 578 (5 February 2020), pp. 53-9, https://doi.org/10.1038/s41586-020-1958-9
J.-L. Vay, A. Almgren, L.D. Amorim, J. Bell (LBNL); L. Ge (SLAC); K. Gott (LBNL); D.P. Grote (LLNL); M. Hogan (SLAC); A. Huebl, R. Jambunathan, R. Lehe, A. Myers (LBNL); C. Ng (SLAC); J. Park, M. Rowan, O. Shapoval, M. Thévenet, W. Zhang, Y. Zhao and E. Zoni (LBNL), “Toward the modeling of chains of plasma accelerator stages with WarpX,” in Proceedings of the 4th European Advanced Accelerator Concepts Workshop (15-20 September 2019, Isola d’Elba, Italy), Journal of Physics: Conference Series 1596, 012059 (18 September 2020) edited by A. Cianchi et al., https://doi.org/10.1088/1742-6596/1596/1/012059
Invited talks without publication venue:
A. Huebl, “Future Computer & Programming Trends,” virtual talk, Snowmass21 Planning meeting. October 2020.
J.-L. Vay and A. Huebl, “Uses of in situ methods in large-scale modeling of plasma-based particle accelerators,” keynote of the virtual ISAV 2020 workshop on In Situ Infrastructures for Enabling Extreme-Scale Analysis and Visualization (November 2020).
2019
L. Chopineau, A. Leblanc (CEA Saclay); G. Blaclard (CEA Saclay and LBNL); A. Denoeud (CEA Saclay); M. Thévenet, J-L. Vay (LBNL); G. Bonnaud, Ph. Martin, H. Vincenti, and F. Quéré (CEA Saclay), “Identification of Coupling Mechanisms between Ultraintense Laser Light and Dense Plasmas,” Physical Review X 9, 011050 (21 March 2019), https://doi.org/10.1103/PhysRevX.9.011050
M.J. Easton (Institute of Heavy Ion Physics, Peking University); H.P. Li (LBNL); Z. Wang, Y.R. Lu (Institute of Heavy Ion Physics, Peking University); and J. Qiang (LBNL), “Simulations of particle interactions in a high-current RFQ,” Journal of Instrumentation 14, T02003 (5 February 2019), https://iopscience.iop.org/article/10.1088/1748-0221/14/02/T02003/meta
Z. Liu (LBNL and IHEP Beijing) and J. Qiang (LBNL), “Implementation of a particle accelerator beam dynamics code on multi-node GPUs,” Journal of Software Engineering and Applications 12, 9 (September 2019), pp. 321-338, http://doi.org/10.4236/jsea.2019.129020
Haithem Kallala (CEA Saclay), Jean-Luc Vay (LBNL), Henri Vincenti (CEA Saclay), “A generalized massively parallel ultra-high order FFT-based Maxwell solver,” Computer Physics Communications 244 (November 2019), pp. 25-34, https://doi.org/10.1016/j.cpc.2019.07.009
Chad C. Mitchell, “Weak Convergence to Equilibrium of Statistical Ensembles in Integrable Hamiltonian Systems,” Journal of Mathematical Physics 60, 052702 (19 May 2019), https://doi.org/10.1063/1.5043419
C. Mitchell, R. Ryne, and K. Hwang, “Spectral Galerkin Solver for Intense Beam Equilibria in Nonlinear Constant Focusing Channels,” Physical Review E 100, 053308 (13 November 2019); https://doi.org/10.1103/PhysRevE.100.053308
E. Hemsing, G. Marcus, W.M. Fawley, R.W. Schoenlein, R. Coffee, G. Dakovski, J. Hastings, Z. Huang, D. Ratner, T. Raubenheimer (SLAC); G. Penn (LBNL), “Soft x-ray seeding studies for the SLAC Linac Coherent Light Source II”, Physical Review Accelerators and Beams 22, 110701 (4 November 2019); https://doi.org/10.1103/PhysRevAccelBeams.22.110701
Ji Qiang, “Advances in global optimization of high brightness beams,” International Journal of Modern Physics A 34 (11 December 2019), 1942016 (16 pages), https://doi.org/10.1142/S0217751X19420168
Ji Qiang, “Emittance growth due to random force error,” Nucl. Instrum. Meth. A 948, 162844 (21 December 2019); https://doi.org/10.1016/j.nima.2019.162844
Ji Qiang, “Fast 3D Poisson solvers in elliptical conducting pipe for space-charge simulation,” Physical Review Accelerators and Beams 22, 104601 (23 October 2019); https://doi.org/10.1103/PhysRevAccelBeams.22.104601
Ji Qiang, “Fast longitudinal beam dynamics optimization in x-ray free electron laser linear accelerators,” Physical Review Accelerators and Beams 22, 094401 (27 September 2019); https://doi.org/10.1103/PhysRevAccelBeams.22.094401
J. Qiang, “Long-term simulation of space-charge effects,” Nucl. Instrum. Meth. A 918 (21 February 2019), pp. 1-8, https://doi.org/10.1016/j.nima.2018.11.114
Invited talks without opportunity for publication
C. Mitchell, “A Study of Beam Equilibria in Strongly Nonlinear Focusing Channels with Applications to IOTA,” FAST/IOTA Collaboration Meeting and Workshop on High Intensity Beams in Rings, Batavia, IL, June 2019.
C. Mitchell, “Exploring Space Charge and Integrability in the IOTA Ring,” Workshop on Physics and Applications of High Brightness Beams (HBB 2019), Rethimno, Crete, Greece, April 2019.
C. Mitchell, “Global Geometry of Integrable Dynamics in IOTA with Applications to Dynamic Aperture,” FAST/IOTA Collaboration Meeting and Workshop on High Intensity Beams in Rings, Batavia, IL, June 2019.
Maxence Thévenet, “Emittance growth due to misalignment in multi-stage laser plasma accelerators”, ALEGRO workshop, CERN, Geneva, Switzerland, March 26-29, 2019.
Ji Qiang, “Space-charge effects in high intensity accelerators,” GARD ABP workshop 1 (Berkeley, CA December 9-10, 2019).
Ji Qiang, “Beam-beam simulations with crab cavities,” 2019 EIC User Group Meeting, 22-26 July, 2019, Paris, France.
Ji Qiang, “Modeling and applications of high intensity/high brightness beams,” Accelerator Seminar, GSI, Darmstadt, Germany, 18 July 2019.
J.-L. Vay, “High Performance Modeling of Laser-Plasma Accelerator Physics”, Laser-Plasma Accelerator Workshop 2019 (LPAW19), Split, Croatia, May 5-10, 2019.
J.-L. Vay, “High-performance computer modeling of conventional and advanced-concept particle accelerators”, Seminar, University of Chicago, April 29, 2019.
J.-L. Vay, “High-performance computer modeling of conventional and advanced-concept particle accelerators”, Seminar, FNAL, April 30, 2019.
Jean-Luc Vay, “Modeling and Simulation” Lectures, CERN Particle Accelerator School on High Gradient Wakefield Acceleration, Sesimbra, Portugal, March 11-22, 2019.
J.-L. Vay, “Novel Numerical Methods for Particle-in-Cell Modeling of Plasmas”, Workshop on “Connecting Micro and Macro Scales: Acceleration, Reconnection, and Dissipation in Astrophysical Plasmas, Kavli Institute for Theoretical Physics, UC Santa Barbara, Sept. 9-12, 2019.
In unrefereed Proceedings of the 2019 North American Particle Accelerator Conference, 1-6 September, Lansing, Michigan (prepress version made available by courtesy of Volker R.W. Schaa pending publication on JACoW.org) D.A. Bizzozero, J. Qiang (LBNL); L. Ge, Z. Li, C.-K. Ng, L. Xiao (SLAC), “Simulation Analysis of the LCLS-II Injector using ACE3P and IMPACT,” WEPLS05. Y. Luo (BNL) et al., inc. J. Qiang, LBNL, “Weak-Strong Beam-Beam Simulation for eRHIC,” TUPLO06. Y. Luo (BNL) et al., inc. J. Qiang, LBNL, “Calculation of Action Diffusion with Crabbed Collision in eRHIC,” TUPLO07. A. Seryi (JLab) et al., incl. J. Qiang, G.L. Sabbi (LBNL), “The US Electron Ion Collider Accelerator Designs,” MOOHC2. |
In unrefereed Proceedings of the 2019 International Particle Accelerator Conference, 19-24 May, Melbourne, Australia, available through JACoW.org J.P. Edelen, N.M. Cook, C.C. Hall, Y. Hu (RadiaSoft LLC), J.-L. Vay (LBNL) “Advanced modeling and optimization of thermionic energy converters,” THPMP047 Yue Hao, Yun Luo, Vadim Ptitsyn, Ji Qiang, “Scaling Properties of the Synchro-Beta Resonance in Crab Crossing Scheme of Future Electron Ion Collider,” MOPRB082. Yue Hao, Vadim Ptitsyn, Ji Qiang, “Electron Beam’s Closed Orbit in the Crab Crossing Scheme of Future Electron-Ion Colliders,” MOPRB081. K. Hwang, C. Mitchell, and R. Ryne, “Chaos Indicators for Studying Dynamic Aperture in the IOTA Ring with Protons,” WEPTS078. B. Li and J. Qiang, “Microbunching Instability Mitigation via Multi-Stage Cancellation,” WEPTS089. B. Li and J. Qiang, “Suppression of Microbunching Instability Through Dispersive Lattice,” WEPTS090. Yun Luo et al., “Combined Strong-Strong and Weak-Strong Beam-Beam Simulations for Crabbed Collision in eRHIC,” MOPRB091. Yun Luo et al., “Simulation Challenges for eRHIC Beam-Beam Study,” MOPRB090. C. Mitchell et al., “Beam Dynamics Studies of an APEX2-Based Photoinjector,” TUPTS080. C. Mitchell and Ji Qiang, “Analysis of Particle Noise in a Gridless Spectral Poisson Solver for Symplectic Multiparticle Tracking,” WEPTS079. Chad Eugene Mitchell, Ji Qiang, “Analysis of Particle Noise in a Gridless Spectral Poisson Solver for Symplectic Multiparticle Tracking,” WEPTS079. Ji Qiang, Lucas Nathan Brouwer, Soren Prestemon, “A Phase Shifter for Multi-Pass Recirculating Proton LINAC,” MOPRB103. Ji Qiang et al., “Integration of Cavity Design and Beam Dynamics Simulation Using the Parallel IMPACT and the ACE3P Codes,” WEPTS088. Ji Qiang et al., ”Emittance Preservation for LCLS-II-HE Project,” WEPTS093. |
In unrefereed Proceedings of the 2019 International Particle Accelerator Conference, 19-24 May, Melbourne, Australia, available through JACoW.org J.P. Edelen, N.M. Cook, C.C. Hall, Y. Hu (RadiaSoft LLC), J.-L. Vay (LBNL) “Advanced modeling and optimization of thermionic energy converters,” THPMP047 Yue Hao, Yun Luo, Vadim Ptitsyn, Ji Qiang, “Scaling Properties of the Synchro-Beta Resonance in Crab Crossing Scheme of Future Electron Ion Collider,” MOPRB082. Yue Hao, Vadim Ptitsyn, Ji Qiang, “Electron Beam’s Closed Orbit in the Crab Crossing Scheme of Future Electron-Ion Colliders,” MOPRB081. K. Hwang, C. Mitchell, and R. Ryne, “Chaos Indicators for Studying Dynamic Aperture in the IOTA Ring with Protons,” WEPTS078. B. Li and J. Qiang, “Microbunching Instability Mitigation via Multi-Stage Cancellation,” WEPTS089. B. Li and J. Qiang, “Suppression of Microbunching Instability Through Dispersive Lattice,” WEPTS090. Yun Luo et al., “Combined Strong-Strong and Weak-Strong Beam-Beam Simulations for Crabbed Collision in eRHIC,” MOPRB091. Yun Luo et al., “Simulation Challenges for eRHIC Beam-Beam Study,” MOPRB090. C. Mitchell et al., “Beam Dynamics Studies of an APEX2-Based Photoinjector,” TUPTS080. C. Mitchell and Ji Qiang, “Analysis of Particle Noise in a Gridless Spectral Poisson Solver for Symplectic Multiparticle Tracking,” WEPTS079. Chad Eugene Mitchell, Ji Qiang, “Analysis of Particle Noise in a Gridless Spectral Poisson Solver for Symplectic Multiparticle Tracking,” WEPTS079. Ji Qiang, Lucas Nathan Brouwer, Soren Prestemon, “A Phase Shifter for Multi-Pass Recirculating Proton LINAC,” MOPRB103. Ji Qiang et al., “Integration of Cavity Design and Beam Dynamics Simulation Using the Parallel IMPACT and the ACE3P Codes,” WEPTS088. Ji Qiang et al., ”Emittance Preservation for LCLS-II-HE Project,” WEPTS093. |
2018
P. Lee, T.L. Audet (CNRS); R. Lehe, J.-L. Vay (LBNL); G. Maynard, B. Cros (CNRS), “Investigation of the dynamics of ionization induced injected electrons under the influence of beam loading effects,” Nucl. Instrum. Meth. A, in press (available online 6 February 2018), https://doi.org/10.1016/j.nima.2018.02.004
Ian T. Lim, Scott A. Lambert (Stanford University); Jean-Luc Vay (LBNL); and Jared W. Schwede (LBNL and Spark Thermionics, Inc.), “Electron reflection in thermionic energy converters,” Applied Physics Letters 112, 7 (February 2018), https://doi.org/10.1063/1.5018067
Zhicong Liu (IHEP, LBNL, and University of Chinese Academy of Sciences) and Ji Qiang (LBNL), “Symplectic multi-particle tracking on GPUs,” Computer Physics Communications, in press (available online 12 February 2018), https://doi.org/10.1016/j.cpc.2018.02.001
Ji Qiang, “Mitigation of envelope instability through fast acceleration in linear accelerators,”
Physical Review Accelerators and Beams 21, 114201 (26 November 2018), https://doi.org/10.1103/PhysRevAccelBeams.21.114201
J. Qiang, “Three-dimensional envelope instability in periodic focusing channels,” Phys. Rev. Accel. Beams 21, 034201 (20 March 2018), https://doi.org/10.1103/PhysRevAccelBeams.21.034201
Olga Shapoval, Jean-Luc Vay (LBNL); Henri Vincenti (CNRS), “Two-step perfectly matched layer for arbitrary-order pseudo-spectral analytical time-domain methods”, Computer Physics Communications 235 (February 2019; online 1 October 2018), pp. 102-110, https://doi.org/10.1016/j.cpc.2018.09.015
J.-L. Vay, A. Almgren, J. Bell (LBNL); L. Ge (SLAC); D.P. Grote (LLNL); M. Hogan, O. Kononenko (SLAC); R.Lehe, A.Myers (LBNL); C. Ng (SLAC); J .Park, R. Ryne. O. Shapoval, M. Thévenet, W. Zhang (LBNL), “Warp-X: A new exascale computing platform for beam–plasma simulations,” Nucl. Instrum. Meth. A, in press (available online 31 January 2018), https://doi.org/10.1016/j.nima.2018.01.035
In unrefereed Proceedings of the 2018 International Computational Accelerator Physics Conference (Key West, Florida, US, Oct. 20-24, 2018), to be published on JACoW.N.M. Cooky, J.P. Edelen, C.C. Hall, M. Keilman, P. Moeller, R. Nagler, J.-L. Vay, “High-fidelity three-dimensional simulations of thermionic energy converters.”
R. Lehe, “Review of spectral Maxwell solvers for electromagnetic Particle-In-Cell: algorithms and advantages (invited). C. Mitchell and J. Qiang, “Analysis of Emittance Growth in a Gridless Spectral Poisson Solver for Fully Symplectic Multiparticle Tracking.” Ji Qiang, “Advances in simulation of high brightness/high intensity beams” R.D. Ryne, “Computational Accelerator Physics: On the Road to Exascale” (invited plenary). J.-L. Vay et al., “Toward Plasma Wakefield Simulations at Exascale.” |
In unrefereed Proceedings of the 2018 Advanced Accelerator Concepts Workshop (Breckenridge, CO, Aug. 12-17, 2018), to be published in AIP Conference Proceedings.R. Lehe, W. An, “Summary report of working group 2: Computations for Accelerator Physics.”
J.-L. Vay, A. Almgren, J. Bell, R. Lehe, A. Myers, J. Park, O. Shapoval, M. Thévenet, W. Zhang, D. P. Grote, M. Hogan, L. Ge, C. Ng, “Toward Plasma Wakefield Simulations at Exascale.” |
At “Numerical Methods for Analysis, Design, and Modelling of Particle Accelerators,” Nov. 2018 CERN Accelerator School: J. Qiang, “Monte Carlo Simulation Techniques.” J. Qiang, “Multi-Particle Simulation Techniques.” |
In unrefereed Proceedings of the 2018 International Particle Accelerator Conference (April 29-May 4, Vancouver, British Columbia, Canada), published on JACoW, 9 October 2018.Yun Luo, Gabriele Bassi, Michael Blaskiewicz, Wolfram Fischer, Yue Hao, Christoph Montag, Vadim Ptitsyn, Victor Smaluk, Ferdinand J. Willeke, Ji Qiang, “Study of Crabbed Collision in eRHIC With a Combination of Strong-Strong and Weak-Strong Simulations,” MOPMF012.
Yue Hao, Yun Luo, Vadim Ptitsyn, Ji Qiang, “Study Progress of the Coupling Resonance of the Crab Crossing Scheme in Electron-Ion Collider,” MOPMK010. C. Mitchell and J. Qiang, “Numerical Tools for Modeling Nonlinear Integrable Optics in IOTA with Intense Space Charge Using the Code IMPACT-Z,” THPAK035. C.E. Mitchell, R.D. Ryne, and F.H. O’Shea, “Accurate Modeling of Fringe Field Effects on Nonlinear Integrable Optics in IOTA,” THPAK036. Yue Tao, Kilean Hwang, Ji Qiang, “Errors Study of a Double-Pass Recirculating Superconducting Proton Linac,” TUPAL031. Yue Tao, Ji Qiang, “A Variable Field Phase-Shifter for Recirculating Proton Linacs,” TUPAL032. Ji Qiang, “Bunched Beam Envelope Instability in a Periodic Focusing Channel,” THPAK040. Ji Qiang, “On Long-Term Space-Charge Tracking Simulation,” THPAK042. Zhicong Liu, Ji Qiang, “Performance Optimization of a Beam Dynamics PIC Code On Hybrid Computer Architectures,” THPAK043. Robert Ryne, Chad Eugene Mitchell, Ji Qiang, Bruce Carlsten, “Self-Consistent Modeling using a Lienard-Wiechert Particle-Mesh Method,” in THPAK044. Kei Fukushima, Michael Davidsaver, Zhengqi He, Masanori Ikegami, Guobao Shen, Takashi Yoshimoto, Tong Zhang, Ji Qiang, “Simulation Code Design for the Interpreted Language Using the Compiled Module,” THPAK049. Matthew J Easton, Haipeng Li, Yuanrong Lu, Zhi Wang, Ji Qiang, “Simulation of Particle Interactions in a High Intensity Radio-Frequency Quadrupole for Molecular Hydrogen Ions,” THPAK075. Haipeng Li, Matthew J Easton, Yuanrong Lu, Zhi Wang, Ji Qiang, “Development and Benchmarking of the IMPACT-T Code,” THPAK076. Biaobin Li, Ji Qiang, “Suppression of Microbunching Instability Using a Quadrupole Inserted Chicane in Free-Electron-Laser Linacs,” THPMF082. Kilean Hwang, Ji Qiang, “Numerical Shot Noise Modeling and Particle Migration Scheme,” THPMF084. Ji Qiang, Scott D. Anderson, David Dowell, Paul J. Emma, John Schmerge, Mark Woodley, Feng Zhou, “Beam Dynamics Simulation of the Solenoid Sextupole Error in the LCLS-II Injector,” THPMF085. Kilean Hwang, Ji Qiang, “Reliability Improvement on Wiggler Period Averaging Approximation,” THPMF086. |
At Workshop on High Performance Computing for Plasma Applications at the 71st Annual Gaseous Electronics Conference J.-L. Vay, “HPC modeling of laser plasma interactions.” |
2017
S. Jalas, I. Dornmair (University of Hamburg); R. Lehe, H. Vincenti, J.-L. Vay (LBNL); M. Kirchen, and A.R. Maier (University of Hamburg), “Accurate modeling of plasma acceleration with arbitrary order pseudo-spectral particle-in-cell methods”, Physics of Plasmas 24 (2017) 033115, http://dx.doi.org/10.1063/1.4978569
M. Placidi (LBNL); S. Di Mitri (Elettra-Sincrotrone Trieste); C. Pellegrini (SLAC and UCLA); G. Penn (LBNL), “Compact FEL-driven inverse compton scattering gamma-ray source”, Nucl. Instrum. Methods A 885 (2017) 55-60, https://doi.org/10.1016/j.nima.2017.02.072
J. Qiang, “A Fast Numerical Integrator for Relativistic Charged Particle Tracking,” Nucl. Instrum. Methods A (online 12 April 2017), https://doi.org/10.1016/j.nima.2017.04.015.
J. Qiang, “Symplectic multiparticle tracking model for self-consistent space-charge simulation,” Physical Review Accelerators and Beams 20, 014203 (23 January 2017), doi:10.1103/PhysRevAccelBeams.20.014203
P.R. Ribič, E. Roussel (Elettra-Sincrotrone Trieste); G. Penn (LBNL); G. De Ninno (Elettra-Sincrotrone Trieste and University of Nova Gorica); L. Giannessi, G. Penco, and E. Allaria (Elettra-Sincrotrone Trieste), “Echo-Enabled Harmonic Generation Studies for the FERMI Free-Electron Laser”, Photonics 4 (2017) 19, http://dx.doi.org/10.3390/photonics4010019
J. Qiang, “High Resolution Beam Modeling and Optimization with IMPACT,” invited talk, Computational Accelerator Physics Session, 2017 American Physical Society April Meeting (January 28-31, 2017, Washington D.C.), http://meetings.aps.org/Meeting/APR17/Session/H7.2 (abstract only; no Proceedings published).
J.-L. Vay, “WARP-X: a new exascale computing platform for Beam-Plasma Simulations”, invited talk, Computational Accelerator Physics Session, 2017 American Physical Society April Meeting (January 28-31, 2017, Washington D.C.), http://meetings.aps.org/Meeting/APR17/Session/H7.3 (abstract only; no Proceedings published).
J.-L. Vay and R. Lehe, “Simulations for Plasma and Laser Acceleration”, Reviews of Accelerator Science and Technology, 9 (2016) pp. 165-186; http://dx.doi.org/10.1142/S1793626816300085
J. Wu (SLAC); N. Hu (Valley Christian High School, San Jose, CA); H. Setiawan (Facility for Rare Isotope Beams, Michigan State University); X. Huang, T. Raubenheimer (SLAC); Y. Jiao (Institute for High Energy Physics, Beijing, PRC); G. Yu (Columbia University); A. Mandleka (Cal Tech); S. Spampinati (Sincrotrone Trieste, Italy); K. Fang (SLAC); C. Chu (Facility for Rare Isotope Beams, Michigan State University); J. Qiang (LBNL), “Multi-dimensional optimization of a terawatt seeded tapered Free Electron Laser with a Multi-Objective Genetic Algorithm,” Nuclear Instruments & Methods in Physics Research A 846 (21 February 2017), pp. 56-63, doi:10.1016/j.nima.2016.11.035
2016
Audet, T.L. (CNRS); Hansson, M. (Lund University); Lee, P., Desforges, F.G., and Maynard, G. (CNRS); Dobosz Dufrénoy, S. (CEA Saclay); Lehe, R., and Vay, J.-L. (LBNL); Aurand, B., Persson, A., and Gallardo González, I. (Lund University); Maitrallain, A. and Monot, P. (CEA Saclay); Wahlström, C.-G., and Lundh, O. (Lund University); and Cros, B. (CNRS), “Investigation of ionization-induced electron injection in a wakefield driven by laser inside a gas cell”, Physics of Plasmas 23, 023110 (16 February 2016), http://dx.doi.org/10.1063/1.4942033
K. Hwang, J. Qiang, “A recirculating proton linac design,” submitted to unrefereed Proceedings of the 2016 North American Particle Accelerator Conference (Chicago, Illinois, US, 9-14 October 2016).
M. Kirchen (LBNL and University of Hamburg); R. Lehe; B.B. Godfrey (University of Maryland and LBNL); I. Dornmair, S. Jalas, K. Peters (University of Hamburg); J.-L. Vay; A.R. Maier (University of Hamburg), “Stable discrete representation of relativistically drifting plasmas,” Phys. Plasmas (letter) 23, 100704 (2016); http://dx.doi.org/10.1063/1.4964770
Remi Lehe, “Advances in spectral PIC codes for laser-wakefield acceleration,” invited talk (no Proceedings), Workshop on the Frontiers of Intense Beam Physics Modeling (Boulder, Colorado, US, 2-5 October 2016).
R. Lehe, M. Kirchen (Univ. of Hamburg), I.A. Andriyash (CNRS), B.B. Godfrey (LBNL and University of Maryland), J.-L. Vay, “A spectral, quasi-cylindrical and dispersion-free Particle-In-Cell algorithm”, Computer Physics Communications, available online 17 February 2016; http://dx.doi.org/10.1016/j.cpc.2016.02.007.
C. Mitchell, J. Qiang, and M. Venturini, “High-resolution beam dynamics modeling for LCLS-II,” invited talk (no Proceedings), Workshop on the Frontiers of Intense Beam Physics Modeling (Boulder, Colorado, US, 2-5 October 2016).
C. Mitchell and J. Qiang, “Accelerator tracking and optimization: advanced-computing simulations with IMPACT,” invited talk (no Proceedings), LCLS-II Facility Advisory Committee Review (SLAC, Menlo Park, CA, July 2016).
C. Mitchell, J. Qiang, and M. Venturini, “Sensitivity of the microbunching instability to irregularities in cathode current in the LCLS-II beam delivery system,” submitted to unrefereed Proceedings of the 2016 North American Particle Accelerator Conference (Chicago, Illinois, US, 9-14 October 2016).
G. Penn, “Challenges in Simulating EEHG,” invited talk (no Proceedings), Workshop on Designing Future X-ray FELs (Daresbury, UK, 31 August-2 September 2016).
G. Penn, J.-L. Vay, R. Lehe, C. Schroeder and E. Esarey, “Beam breakup studies in a hollow plasma channel,” submitted to unrefereed Proceedings of the 17th Advanced Accelerator Concepts Workshop (National Harbor, Maryland, US, July 31-August 5, 2016).
J. Qiang, “A new RFQ model and symplectic multi-particle tracking in the IMPACT code suite,” invited talk (no paper submitted), HB2016, the 57th ICFA Advanced Beam Dynamics Workshop on High-Intensity and High-Brightness Hadron Beams (Malmo, Sweden, 3-8 July 2016).
J. Qiang, “A parallel multi-physics beam dynamics simulation package: IMPACT,” invited talk (no Proceedings), JLEIC Collaboration Meeting Fall 2016 (Newport News, Virginia, US, 5 October 2016).
J. Qiang, “Beam-beam simulations,” talk (no Proceedings), JLEIC Collaboration Meeting Spring 2016 (Newport News, Virginia, US, 529-31 March 2016).
J. Qiang, “Computational methods in the space-charge simulation code: IMPACT,” invited talk (no Proceedings), Workshop on the Frontiers of Intense Beam Physics Modeling (Boulder, Colorado, US, 2-5 October 2016).
J. Qiang, “Multi-physics simulations using high performance computing for FEL design optimization,” invited talk (no Proceedings), Workshop on Challenges of High Photon Energy, High-Repetition Rate XFELs, A MaRIE Workshop” (Santa Fe, New Mexico, US, 9-10 August 2016).
J. Qiang, K. Hwang, “Modeling of dark current generation and transport using the IMPACT-T code,” submitted to unrefereed Proceedings of the 2016 North American Particle Accelerator Conference (Chicago, Illinois, US, 9-14 October 2016).
J. Qiang, C. Mitchell, A. Qiang, “Tuning of an adaptive unified differential evolution algorithm for global optimization,” submitted to refereed Proceedings of 2016 IEEE Congress on Evolutionary Computation (Vancouver, CA, 24-29 July 2016).
J. Qiang, R.D. Ryne, Y. Hao, “Benchmark of strong-strong beam-beam aimulation of the kink instability in an electron ion collider design,”submitted to unrefereed Proceedings of the 2016 North American Particle Accelerator Conference (Chicago, Illinois, US, 9-14 October 2016).
J. Qiang, Y. Ding, P. Emma, Z. Huang, D. Ratner, T. Raubenheimer, F. Zhou, “Simulation of the shot-noise driven microbunching instability experiment at the LCLS,” submitted to unrefereed Proceedings of the 2016 North American Particle Accelerator Conference (Chicago, Illinois, US, 9-14 October 2016).
Rubel, O., Loring, B., Vay, J.-L., Grote, D., Lehe, R., Bulanov, S., Vincenti, H., Bethel, E.W., “In situ visualization and analysis of ion accelerator simulations using Warp and VisIt”, IEEE Computer Graphics and Applications 36, 22–35 (May-June 2016), http://doi.ieeecomputersociety.org/10.1109/MCG.2016.62
R. Ryne, “Large-Scale Simulation of 3D Radiative Phenomena using a Lienard-Wiechert Particle-Mesh (LWPM) Approach,” invited talk (no publication), Workshop on the Frontiers of Intense Beam Physics Modeling (Boulder, Colorado, US, 2-5 October 2016).
J.-L. Vay, “A selection of advanced methods beyond standard PIC,” invited talk (no Proceedings), Workshop on the Frontiers of Intense Beam Physics Modeling (Boulder, Colorado, US, 2-5 October 2016).
J.-L. Vay, “Electromagnetic PIC simulations of free electron lasers in an optimal Lorentz boosted frame,” invited talk (no Proceedings), Workshop on Designing Future X-ray FELs (Daresbury, UK, 31 August-2 September 2016).
J.-L. Vay, “The Berkeley Lab Accelerator Simulation Toolkit,” invited talk (no Proceedings), Workshop on Designing Future X-ray FELs (Daresbury, UK, 31 August-2 September 2016).
J.-L. Vay, “Recent advances in PIC simulations of relativistic plasmas,” Conference on “Feedback over 44 orders of magnitude: from gamma-rays to the universe” (invited talk; no Proceedings), Perimeter Institute for Theoretical Physics (Toronto, Canada, 14-16 March 2016).
J.-L. Vay, “The Berkeley Lab Accelerator Simulation Toolkit,” invited talk (no Proceedings), Workshop on Designing Future X-ray FELs (Daresbury, UK, 31 August-2 September 2016).
J.-L. Vay, G. Blaclard, R. Lehe, M. Lobet, M. Kirchen, H. Vincenti, P. Lee, B.B. Godfrey, “High-performance modeling of plasma-based acceleration & laser-plasma interactions,” submitted to unrefereed Proceedings of the 2016 North American Particle Accelerator Conference (Chicago, Illinois, US, 9-14 October 2016).
J.-L. Vay, R. Lehe; H. Vincenti (CEA-Saclay and LBNL); B.B. Godfrey (University of Maryland and LBNL); I. Haber (University of Maryland); P. Leed (CNRS), “Recent advances in high-performance modeling of plasma-based acceleration using the full PIC method,” in refereed Proceedings of the 2015 European Advanced Accelerator Concepts Workshop (Elba, Italy, 13-19 September 2015), Nucl. Instrum. Meth. A 829 (1 September 2016), pp. 353-7, http://dx.doi.org/10.1016/j.nima.2015.12.033
H. Vincenti, J.-L. Vay, “Detailed analysis of the effects of stencil spatial variations with arbitrary high-order finite-difference Maxwell solver,” Computer Physics Communications 200, 147 (March 2016), http://dx.doi.org/10.1016/j.cpc.2015.11.009.
2015
C. Benedetti, F. Rossi, C. B. Schroeder, E. Esarey, and W.P. Leemans, Pulse evolution and plasma wave phase velocity in channel-guided laser-plasma accelerators, submitted (2015).
C. Benedetti, C.B. Schroeder, E. Esarey, C.G.R. Geddes, W.P. Leemans, “Efficient Modeling of Laser-Plasma Accelerators with INF&RNO,” Proc. of the 14th Advanced Accelerator Concepts Workshop, Annapolis, MD, USA, June 13-19, 2010, AIP Conf. Proc. 1299, 250-255 (2010).
C. Benedetti, E. Esarey, W. Leemans, C.B. Schroeder, “Efficient modeling of laser-plasma accelerators using the ponderomotive-based code INF&RNO,” session THAAI2, Proceedings of ICAP2012, Rostock-Warnemünde, Germany.
C. Benedetti, E. Esarey, W. Leemans, C. B. Schroeder, “Modeling a 10 GeV Laser-Plasma Accelerator with INF&RNO,” MOP082, Proc. PAC11 (New York, NY, USA, March 28-April 1, 2011).
Jungbae Bahng (Kyungpook National University); Ji Qiang; Eun-San Kim (Korea University Sejong Campus), “Design study of low-energy beam transport for multi-charge beams at RAON”, Nucl. Instrum. Meth. A 804 (September 2015), pp. 99-107, http://dx.doi.org/10.1016/j.nima.2015.09.041.
N. A. Bobrova, P. V. Sasorov, C. Benedetti, S. S. Bulanov, C. G. R. Geddes, C. B. Schroeder, E. Esarey, and W. P. Leemans, “Laser-heater assisted plasma channel formation in capillary discharge waveguides,” Phys. Plasmas 20, 020703 (2013).
A. Bonatto, C.B. Schroeder, J.-L. Vay, C.G.R. Geddes, C. Benedetti, E. Esarey, and W.P. Leemans, Passive and active plasma-based decelerating schemes for the compact disposal of highly-relativistic electron beams, submitted (2015).
C. Benedetti, C. B. Schroeder, E. Esarey, F. Rossi, W. P. Leemans, “Numerical investigation of electron self-injection in the nonlinear bubble regime,” Phys. Plasmas 20, 103108 (2013). C. Benedetti, C. B. Schroeder, E. Esarey, W. P. Leemans, “Quasi-matched propagation of ultra-short, intense laser pulses in plasma channels,” Phys. Plasmas 12, 053101 (2012).
P. Emma, J.C. Frisch, Z. Huang, H. Loos, A. Marinelli, T.J. Maxwell, Y. Nosochkov, T.O. Raubenheimer, L. Wang, J.J. Welch, and M. Woodley (SLAC); J. Qiang and M. Venturini (LBNL); A. Saini and N. Solyak (Fermilab), “Linear accelerator design for the LCLS-II FEL facility,” in unrefereed Proceedings of the 2014 Free Electron Laser Conference (Basel, Switzerland, 25-29 August 2014), JACoW prepress, contribution THP025.
C.G.R. Geddes, Cs. Tóth, J. van Tilborg, E. Esarey, C.B. Schroeder, D. Bruhwiler, C. Nieter, J. Cary, and W.P. Leemans, “Production of high quality electron bunches by dephasing and beam loading in channeled and unchanneled laser plasma accelerators,” Phys. Plasmas 12, 056709 (2005).
B.B. Godfrey (University of Maryland and LBNL) and J.-L. Vay, “Numerical stability of relativistic beam multidimensional PIC simulations employing the Esirkepov algorithm,” Journal of Computational Physics 248, pp. 33-46 (2013); dx.doi.org/10.1016/j.jcp.2013.04.006.
B.B. Godfrey (University of Maryland and LBNL) and J.-L. Vay, “Suppressing the numerical Cherenkov instability in FDTD PIC codes,” Journal of Computational Physics 267, 1-6 (2014); dx.doi.org/10.1016/j.jcp.2014.02.022.
B.B. Godfrey (University of Maryland and LBNL), J.-L. Vay, and I. Haber (University of Maryland), “Numerical Stability Improvements for the Pseudospectral EM PIC Algorithm,” IEEE Transactions on Plasma Science 42, 1339-1344 (2014); dx.doi.org/10.1109/TPS.2014.2310654.
B.B. Godfrey (University of Maryland and LBNL), J.-L. Vay, and I. Haber (University of Maryland), “Numerical stability analysis of the pseudo-spectral analytical time-domain PIC algorithm,” Journal of Computational Physics 258, 689-704 (2014); dx.doi.org/10.1016/j.jcp.2013.10.053.
A.J. Gonsalves, K. Nakamura, J. Daniels, H.-S. Mao, C. Benedetti, C.B. Schroeder, Cs. Tóth, J. van Tilborg, D E. Mittelberger, S. S. Bulanov, J.-L. Vay, C.G.R. Geddes, E. Esarey, and W.P. Leemans, “Generation and pointing stabilization of multi-GeV electron beams from a laser plasma accelerator driven in a pre-formed plasma waveguide,” accepted for publication in Phys. Plasmas (2015).
A.J. Gonsalves, K. Nakamura, C. Lin, D. Panasenko, S. Shiraishi, T. Sokollik, C. Benedetti, C. B. Schroeder, C. G. R. Geddes, J. van Tilborg, J. Osterhoff, E. Esarey, C. Tóth, W.P. Leemans, “Tunable Laser Plasma Accelerator based on Longitudinal Density Tailoring,” Nature Physics 7, 862 (2011), doi:10.1038/nphys2071.
A. He, F.J. Willeke, L. Yang, and L.-H. Yu (BNL); J. Qiang (LBNL), “Benchmark and simulation design of a low energy bunch compressor in unrefereed Proceedings of the 2014 Free Electron Laser Conference (Basel, Switzerland, 25-29 August 2014), JACoW prepress, contribution THP036.
P. Lee, T.L. Audet, R. Lehe, J.-L. Vay, G. Maynard, B. Cros, “Modeling laser-driven electron acceleration using WARP with Fourier decomposition,” in Proceedings of the 2nd European Advanced Accelerator Concepts Workshop (Isola d’Elba, Italy, 13-19 September 2015), Nucl. Instrum. Meth. A (in press), corrected proof available online 31 December 2015, ISSN 0168-9002, http://dx.doi.org/10.1016/j.nima.2015.12.036.
K.V. Lotov (Novosibirsk State University and BINP), J.-L. Vay, “Summary of working group 6: Theory and simulations,” in Proceedings of the 2nd European Advanced Accelerator Concepts Workshop (Isola d’Elba, Italy, 13-19 September 2015), Nucl. Instrum. Meth. A (in press), corrected proof available online 18 December 2015, ISSN 0168-9002, http://dx.doi.org/10.1016/j.nima.2015.12.014.
W.P. Leemans, A.J. Gonsalves, H.-S. Mao, K. Nakamura, C. Benedetti, C.B. Schroeder, Cs. Tóth, J. Daniels, D.E. Mittelberger, S.S. Bulanov, J.-L. Vay, C.G.R. Geddes, and E. Esarey, “Multi-GeV Electron Beams from Capillary-Discharge-Guided Subpetawatt Laser Pulses in the Self-Trapping Regime,” Physical Review Letters 113, 245002 (8 December 2014).
C.E. Mitchell, D. Filippetto, R. Huang, C. F. Papadopoulos, H.J. Qian, J. Qiang, F. Sannibale, and M. Venturini, “Higher-order moment models of longitudinal pulse shape evolution in photoinjectors,” in unrefereed Proceedings of the 2014 Free Electron Laser Conference (Basel, Switzerland, 25-29 August 2014), JACoW prepress, contribution THPP019.
J. Qiang and C.E. Mitchell, “Electron beam dynamics optimization using a unified differential evolution algorithm,” in unrefereed Proceedings of the 2014 Free Electron Laser Conference (Basel, Switzerland, 25-29 August 2014), JACoW prepress, contribution THPP020.
J. Qiang and S. Paret (LBNL); G. Arduini and T. Pieloni (CERN); and J. Barranco (EPFL), “Strong-strong beam-beam simulation for the LHC Upgrade,” in unrefereed Proceedings of IPAC ’14, the 5th International Particle Accelerator Conference (Dresden, Germany, 15-20 June 2014), JACoW, contribution TUPRO006, p. 1006.
J. Qiang et al., “Start-to-end simulation of x-ray radiation of a next generation light source using the real number of electrons,” Phys. Rev. ST:AB 17 (20 March 2014) 030701..
C.B. Schroeder, C. Benedetti, S.S. Bulanov, M. Chen, E. Esarey, C.G.R. Geddes, J.-L. Vay, L.-L. Yu, and W.P. Leemans, Beam emittance using two-color ionization injection into laser-plasma accelerators, SPIE Optics + Optoelectronics Conference Proceedings..
C.B. Schroeder, C. Benedetti, E. Esarey, W.P. Leemans, “Beam loading in a plasma-based accelerator using a near-hollow plasma channel,” Phys. Plasmas 20, 123115 (2013).
C.B. Schroeder, E. Esarey, C. Benedetti, W.P. Leemans, “Control of focusing forces and emittances in plasma-based accelerators using near-hollow plasma channels,” Phys. Plasmas 20, 080701 (August 2013).
C.B. Schroeder, E. Esarey, C. Geddes, C. Benedetti, W.P. Leemans, “Physics considerations for laser-plasma linear colliders,” Phys. Rev. ST Accel. Beams, 13, 1010301 (2010).
C.B. Schroeder, C. Benedetti, E. Esarey, J. van Tilborg, W.P. Leemans, “Group velocity and pulse lengthening of mismatched laser pulses in plasma channels,” Phys. Plasmas 18, 083103 (2011).
C.B. Schroeder, C. Benedetti, E. Esarey, W.P. Leemans, “Nonlinear pulse propagation and phase velocity of laser-driven plasma waves,” Phys. Rev. Lett. 106, 135002 (2011).
S. Shiraishi, C. Benedetti, A. J. Gonsalves, K. Nakamura, B. H. Shaw, T. Sokollik, J. van Tilborg, C. G. R. Geddes, C. B. Schroeder, Cs. Tóth, E. Esarey, W. P. Leemans, “Laser red shifting based characterization of wakefield excitation in a laser-plasma accelerator,” Phys. Plasmas 20, 063103 (2013).
S. Shiraishi, T. Sokollik, C. Benedetti, A. J. Gonsalves, K. Nakamura, B. H. Shaw, J. van Tilborg, C.G.R. Geddes, C.B. Schroeder, Cs. Tóth, E. Esarey, and W.P. Leemans, “Recent progress on staging laser-plasma accelerators,” in Proceedings of Advanced Accelerator Concepts 2012 (Austin, TX, USA), AIP Conf. Proc. 1507, pp. 321-326.
J.-L. Vay, R. Lehe, H. Vincenti (LBNL and CEA-Saclay), B.B. Godfrey (LBNL and University of Maryland), I. Haber (University of Maryland, P. Lee (CNRS), “Recent advances in high-performance modeling of plasma-based acceleration using the full PIC method,” in Proceedings of the 2nd European Advanced Accelerator Concepts Workshop (Isola d’Elba, Italy, 13-19 September 2015), Nucl. Instrum. Meth. A (in press), corrected proof available online 22 December 2015, ISSN 0168-9002, http://dx.doi.org/10.1016/j.nima.2015.12.033.
H. Vincenti, J.-L. Vay, “Detailed analysis of the effects of stencil spatial variations with arbitrary high-order finite-difference Maxwell solver,” Computer Physics Communications, corrected proof available online 22 November 2015, ISSN 0010-4655, http://dx.doi.org/10.1016/j.cpc.2015.11.009.
J-L Vay and B.B. Godfrey (University of Maryland and LBNL), “Modeling of relativistic plasmas with the Particle-In-Cell method”, in Theoretical and Numerical Approaches for Vlasov-Maxwell Equations, Comptes Rendus M√©canique 342, 10‚Äì11 (2014), pp. 610-618; http://dx.doi.org/10.1016/j.crme.2014.07.006.
J.-L. Vay, I. Haber and B.B. Godfrey, “A domain decomposition method for pseudo-spectral electromagnetic simulations of plasmas,” Journal of Computational Physics 243 (2013), pp. 260-268.
J.-L. Vay, C.G.R. Geddes, S.G. Rykovanov, C.B. Schroeder, E. Esarey, and W.P. Leemans, “Laser-Driven Plasma Deceleration of Electron Beams for Compact Photon Sources,” in Proceedings of the World Symposium on Nuclear Physics and Gamma-Ray Sources for Nuclear Security and Nonproliferation (Tokai, Japan,28-30 January 2014), World Scientific: December 2014, pp. 77-84; http://dx.doi.org/10.1142/9397.
J.-L. Vay, C.G.R. Geddes, E. Cormier-Michel and D.P. Grote, “Design of 10 GeV-1 TeV laser wakefield accelerators using Lorentz boosted simulations,” Physics of Plasmas 18 (2011) 123103.
J.-L. Vay, C.G.R. Geddes, E. Cormier-Michel and D.P. Grote, “Effects of hyperbolic rotation in Minkowski space on the modeling of plasma accelerators in a Lorentz boosted frame,” Physics of Plasmas (letter) 18 (2011), 030701. See also the related LBNL and NERSC news releases and the DOE Office of Science stories.
J.-L. Vay, ““Simulation of beams or plasmas crossing at relativistic velocity,” Physics of Plasmas 15 (2008) 056701; LBNL-63828.
J.-L. Vay, “Noninvariance of space- and time-scale ranges under a Lorentz transformation and the implications for the study of relativistic interactions,” Physical Review Letters 98 (2007), 130405. See also the related article, this LBNL feature story, and a DOE Office of Science Highlight.
L. Wang, P. Emma, Y. Nosochkov, T.O. Raubenheimer, M. Woodley, and F. Zhou (SLAC); C.F. Papadopoulos, J. Qiang, and M. Venturini (LBNL), “MOGA optimization design of LCLS-II linac configurations,” in unrefereed Proceedings of the 2014 Free Electron Laser Conference (Basel, Switzerland, 25-29 August 2014), JACoW prepress, contribution THP029.
L.-L. Yu, E. Esarey, C.B. Schroeder, J.-L. Vay, C. Benedetti, C.G.R. Geddes, M. Chen, and W.P. Leemans, “Two-Color Laser-Ionization Injection,” Phys. Rev. Lett. 112, 125001 (2014); dx.doi.org/10.1103/PhysRevLett.112.125001.
L.-L. Yu, C. B. Schroeder, F.-Y. Li, C. Benedetti, M. Chen, S.-M. Weng, Z.-M. Sheng, and E. Esarey, Control of focusing fields for positron acceleration in nonlinear plasma wakes using multiple laser modes, Phys. Plasmas 21, 120702 (2014).