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

作者：Ju J^*; Svensson K; Ferrari H; Doepp A; Genoud G; Wojda F; Burza M; Persson A; Lundh O; Wahlstrom C G; Cros B

来源：Physics of Plasmas, 2013, 20(8): 083106.

DOI：10.1063/1.4817747

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 10 21 ph/s/mm(2)/mrad(2)/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 the beam charge. The experimental results are in good agreement with 3D particle-in-cell (PIC) simulation.

• 出版日期2013-8