High-order corrections for the electron capture and acceleration by an ultraintense Gaussian laser beam

By means of 3D test particle simulation programs, the effect caused by the high-order corrections of Gaussian laser fields on the electron dynamics in a stationary ultraintense laser beam is examined. In this letter, special attention is given to the studying of the capture phenomenon (J. X. Wang et al., Phys. Rev. E58, 6575 (1998)), which shows interesting prospect making it to become a viable mechanism for laser-driven GeV electron accelerators without media involved. It was found that as w(0) greater than or equal to 50, where w(0) is the beam width at the focus center, the paraxial approxi mation field (PAF) is good enough for reproducing all the electron dynamic characteristics, not only in qualitative detail, but also in quantitative d etail.