Laser wakefield acceleration with active feedback at 5 Hz

We describe the use of a genetic algorithm to apply active feedback to a laser wakefield accelerator at a higher power (10 TW) and a lower repetition rate (5 Hz) than previous work. The temporal shape of the drive laser pulse was adjusted automatically to optimize the properties of the electron beam. By changing the software configuration, different properties could be improved. This included the total accelerated charge per bunch, which was doubled, and the average electron energy, which was increased from 22 to 27 MeV. Using experimental measurements directly to provide feedback allows the system to work even when the underlying acceleration mechanisms are not fully understood, and, in fact, studying the optimized pulse shape might reveal new insights into the physical processes responsible. Our work suggests that this technique, which has already been applied with low-power lasers, can be extended to work with petawatt-class laser systems.

[1]  R. Noll.  Zernike polynomials and atmospheric turbulence , 1976 .

[2]  Ferenc Krausz,et al.  Laser-driven soft-X-ray undulator source , 2009 .

[3]  G. Lambert,et al.  Femtosecond x rays from laser-plasma accelerators , 2013, 1301.5066.

[4]  T. Tajima,et al.  Laser Electron Accelerator , 1979 .

[5]  C. Dong,et al.  High-Flux Femtosecond X-Ray Emission from Controlled Generation of Annular Electron Beams in a Laser Wakefield Accelerator. , 2016, Physical review letters.

[6]  Gerard V. Trunk,et al.  A Problem of Dimensionality: A Simple Example , 1979, IEEE Transactions on Pattern Analysis and Machine Intelligence.

[7]  V Malka,et al.  Single shot phase contrast imaging using laser-produced Betatron x-ray beams. , 2011, Optics letters.

[8]  Harjinder Singh,et al.  Genetic algorithm optimization of laser pulses for molecular quantum state excitation. , 2010, The Journal of chemical physics.

[9]  J. W. Yoon,et al.  Quasi-monoenergetic multi-GeV electron acceleration by optimizing the spatial and spectral phases of PW laser pulses , 2018 .

[10]  Antonio Lucianetti,et al.  Kilowatt average power 100 J-level diode pumped solid state laser , 2017 .

[11]  Zulfikar Najmudin,et al.  X-ray phase contrast imaging of biological specimens with femtosecond pulses of betatron radiation from a compact laser plasma wakefield accelerator , 2011 .

[12]  A. E. Dangor,et al.  Monoenergetic beams of relativistic electrons from intense laser–plasma interactions , 2004, Nature.

[13]  J. Nees,et al.  Coherent control of plasma dynamics by feedback-optimized wavefront manipulationa) , 2015 .

[14]  Y Fainman,et al.  Wave-front generation of Zernike polynomial modes with a micromachined membrane deformable mirror. , 1999, Applied optics.

[15]  K. Nakamura,et al.  Multi-GeV electron beams from capillary-discharge-guided subpetawatt laser pulses in the self-trapping regime. , 2014, Physical review letters.

[16]  E. Springate,et al.  Temporal feedback control of high-intensity laser pulses to optimize ultrafast heating of atomic clusters , 2018, Applied Physics Letters.

[17]  K. Nakamura,et al.  Compact quasi-monoenergetic photon sources from laser-plasma accelerators for nuclear detection and characterization ☆ , 2015 .

[18]  Sebastian M. Pfotenhauer,et al.  A compact synchrotron radiation source driven by a laser-plasma wakefield accelerator , 2008 .

[19]  J. Nees,et al.  Coherent control of plasma dynamics , 2014, Nature Communications.

[20]  Pierre Tournois,et al.  Acousto-optic programmable dispersive filter for adaptive compensation of group delay time dispersion in laser systems , 1997 .

[21]  D. Kane,et al.  Characterization of arbitrary femtosecond pulses using frequency-resolved optical gating , 1993 .

[22]  N. Hafz,et al.  Laser acceleration in argon clusters and gas media , 2016 .

[23]  B. S. Rao,et al.  Effect of chirp on self-modulation and laser wakefield electron acceleration in the regime of quasimonoenergetic electron beam generation , 2013 .

[24]  Koichi Yamakawa,et al.  Ultrarelativistic electron generation during the intense, ultrashort laser pulse interaction with clusters , 2007 .

[25]  S. Kneip,et al.  Controlling the spectrum of x-rays generated in a laser-plasma accelerator by tailoring the laser wavefront , 2009, 0909.3440.

[26]  Juhao Wu,et al.  An algorithm for online optimization of accelerators , 2013 .

[27]  Miroslav Krstic,et al.  Beam matching adaptive control via extremum seeking , 2007 .

[28]  T. Ditmire,et al.  Quasi-monoenergetic laser-plasma acceleration of electrons to 2 GeV , 2013, Nature Communications.

[29]  W. Mori,et al.  Role of Direct Laser Acceleration of Electrons in a Laser Wakefield Accelerator with Ionization Injection. , 2015, Physical review letters.

[30]  John A. Nelder,et al.  A Simplex Method for Function Minimization , 1965, Comput. J..

[31]  Kompa,et al.  Whither the future of controlling quantum phenomena? , 2000, Science.

[32]  Compact laser accelerators for X-ray phase-contrast imaging , 2014, Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences.

[33]  Antoine Rousse,et al.  Production of a keV x-ray beam from synchrotron radiation in relativistic laser-plasma interaction. , 2004, Physical review letters.

[34]  Wavefront Degradation of a 200 TW Laser from Heat-Induced Deformation of In-Vacuum Compressor Gratings , 2018, 2018 Conference on Lasers and Electro-Optics (CLEO).

[35]  Rainer Storn,et al.  Differential Evolution – A Simple and Efficient Heuristic for global Optimization over Continuous Spaces , 1997, J. Glob. Optim..

[36]  S R Nagel,et al.  Observation of synchrotron radiation from electrons accelerated in a petawatt-laser-generated plasma cavity. , 2008, Physical review letters.

[37]  Kazuhisa Nakajima,et al.  Stable multi-GeV electron accelerator driven by waveform-controlled PW laser pulses , 2017, Scientific Reports.

[38]  Jun Zhang,et al.  Adaptive-feedback spectral-phase control for interactions with transform-limited ultrashort high-power laser pulses. , 2014, Optics letters.

[39]  F. Albert,et al.  Applications of laser wakefield accelerator-based light sources , 2016 .

[40]  J. Cary,et al.  High-quality electron beams from a laser wakefield accelerator using plasma-channel guiding , 2004, Nature.

[41]  S. Karsch,et al.  Tunable all-optical quasimonochromatic thomson x-ray source in the nonlinear regime. , 2015, Physical review letters.

[42]  A. Erlandson,et al.  High average power, diode pumped petawatt laser systems: a new generation of lasers enabling precision science and commercial applications , 2017, Optics + Optoelectronics.

[43]  Y. Glinec,et al.  A laser–plasma accelerator producing monoenergetic electron beams , 2004, Nature.

[44]  Wim Leemans,et al.  Trapping, dark current, and wave breaking in nonlinear plasma waves , 2004 .

[45]  John M. Dawson,et al.  Nonlinear Electron Oscillations in a Cold Plasma , 1959 .