Polychromatic x-ray radiation has been produced during the relativistic interaction of a 50-TW femtosecond laser with a helium gas jet. We have characterized the spectrum and the angular distribution of the x-ray emission as well as its dependency on the laser polarization and on the plasma electronic density. We have observed a broad continuous spectrum peaking at 0.15 keV with a significant tail up to 2 keV. The radiation was fairly collimated.
© 2003 Optical Society of America
(300.6560) Spectroscopy : Spectroscopy, x-ray
(320.7090) Ultrafast optics : Ultrafast lasers
(340.7480) X-ray optics : X-rays, soft x-rays, extreme ultraviolet (EUV)
(350.5400) Other areas of optics : Plasmas
K. Ta Phuoc, A. Rousse, L. Notebaert, M. Pittman, J. P. Rousseau, V. Malka, S. Fritzler, S. Sebban, P. Balcou, D. Hulin, J. R. Marqués, and P. G. David, "Polychromatic x-ray production in helium from a femtosecond high-intensity laser system," J. Opt. Soc. Am. B 20, 221-223 (2003)