Study of electron acceleration and x-ray radiation as a function of plasma density in capillary-guided laser wakefield accelerators

Laser wakefield electron acceleration in the blow-out regime and the associated betatron X-ray radiation were investigated experimentally as a function of the plasma density in a configuration where the laser is guided. Dielectric capillary tubes were employed to assist the laser keeping self-focused over a long distance by collecting the laser energy around its central focal spot. With a 40 fs, 16 TW pulsed laser, electron bunches with tens of pC charge were measured to be accelerated to an energy up to 300 MeV, accompanied by X-ray emission with a peak brightness of the order of 1021 ph/s/mm2/mrad2/0.1%BW. Electron trapping and acceleration were studied using the emitted X-ray beam distribution to map the acceleration process; the number of betatron oscillations performed by the electrons was inferred from the correlation between measured X-ray fluence and beam charge. A study of the stability of electron and X-ray generation suggests that the fluctuation of X-ray emission can be reduced by stabilizing ...

[1]  Brigitte Cros,et al.  Characterization of temporal and spatial distribution of hydrogen gas density in capillary tubes for laser-plasma experiments , 2012 .

[2]  Eric Esarey,et al.  Physics of laser-driven plasma-based electron accelerators , 2009 .

[3]  Electron acceleration by laser wakefield and x-ray emission at moderate intensity and density in long plasmas , 2011 .

[4]  Eric Esarey,et al.  Low-emittance electron bunches from a laser-plasma accelerator measured using single-shot x-ray spectroscopy. , 2012 .

[5]  Erik Lefebvre,et al.  Particle-in-Cell modelling of laser-plasma interaction using Fourier decomposition , 2009, J. Comput. Phys..

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

[7]  M. Tzoufras,et al.  Generating multi-GeV electron bunches using single stage laser wakefield acceleration in a 3D nonlinear regime , 2007 .

[8]  Alexander Pukhov,et al.  X-ray generation in an ion channel , 2003 .

[9]  G. Matthieussent,et al.  Eigenmodes for capillary tubes with dielectric walls and ultraintense laser pulse guiding. , 2002, Physical review. E, Statistical, nonlinear, and soft matter physics.

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

[11]  Modelling of laser-plasma electron acceleration in capillary tubes , 2011 .

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

[13]  C. Wahlström,et al.  Enhancement of x-rays generated by a guided laser wakefield accelerator inside capillary tubes , 2012 .

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

[15]  Anders Persson,et al.  Laser-plasma electron acceleration in dielectric capillary tubes , 2011 .

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

[17]  Theoretical and experimental study of laser beam propagation in capillary tubes for non-symmetrical coupling conditions , 2010 .

[18]  Alexander Thomas,et al.  Scalings for radiation from plasma bubbles , 2010 .

[19]  Eric Esarey,et al.  Tunable laser plasma accelerator based on longitudinal density tailoring , 2011 .

[20]  D. Jaroszynski,et al.  Laser-driven plasma waves in capillary tubes. , 2009, Physical review. E, Statistical, nonlinear, and soft matter physics.

[21]  K. Nakamura,et al.  GeV electron beams from a centimetre-scale accelerator , 2006 .

[22]  Zulfikar Najmudin,et al.  Bright spatially coherent synchrotron X-rays from a table-top source , 2010 .

[23]  D. Umstadter.  Laser-Wakefield Accelerators: Glass-guiding benefits , 2011 .

[24]  M. Mostafavi,et al.  Absolute calibration for a broad range single shot electron spectrometer , 2006 .

[25]  On the stability of laser wakefield electron accelerators in the monoenergetic regime , 2007 .

[26]  R. Fonseca,et al.  Measurements of the critical power for self-injection of electrons in a laser wakefield accelerator. , 2009, Physical review letters.

[27]  Characterization of the beam loading effects in a laser plasma accelerator , 2010 .

[28]  S R Nagel,et al.  Near-GeV acceleration of electrons by a nonlinear plasma wave driven by a self-guided laser pulse. , 2009, Physical review letters.

[29]  A. Rousse,et al.  Imaging Electron Trajectories in Laser Wakefield Cavity using betatron X-Ray Radiation , 2006, 2007 Conference on Lasers and Electro-Optics (CLEO).

[30]  Michael Schnell,et al.  Deducing the electron-beam diameter in a laser-plasma accelerator using x-ray betatron radiation. , 2012, Physical review letters.

[31]  U Schramm,et al.  Generation of stable, low-divergence electron beams by laser-wakefield acceleration in a steady-state-flow gas cell. , 2008, Physical review letters.

[32]  U Schramm,et al.  Absolute charge calibration of scintillating screens for relativistic electron detection. , 2010, The Review of scientific instruments.

[33]  P. Brijesh,et al.  Mapping the x-ray emission region in a laser-plasma accelerator. , 2011, Physical review letters.

[34]  Controlled electron injection in a laser-plasma accelerator , 2007 .

[35]  E. Esarey,et al.  Synchrotron radiation from electron beams in plasma-focusing channels. , 2002, Physical review. E, Statistical, nonlinear, and soft matter physics.

[36]  Z. Najmudin,et al.  Current filamentation instability in laser wakefield accelerators. , 2011, Physical review letters.