1. T.. Tajima and J. M. Dawson, Phys. Rev. Lett. 43, 267 (1979).
2. [2]’ E. Esarey, et al., IEEE Trans. On Plasma Sci. 24, 252 (1996).
3. W. D. Kimura et al., PRL 92, 054801 (2004).
4. [4]C. D. Barnes, E. R. Colby, and T. Plettner, p.294 in Advanced Accelerator Concepts: Tenth Workshop, eds. C. E. Clayton and P. Muggli, Amer. Inst.of Physics Press CP647, New York (2002).
5. M. J. Hogan, et al. Phys. Plasmas
7, 2241 (2000).