Research Article

Dynamics of nanometer-scale foil targets irradiated with relativistically intense laser pulses

R. Hörlein^a1a2, S. Steinke^a3 c1, A. Henig^a1a2, S.G. Rykovanov^a1a2, M. Schnürer^a3, T. Sokollik^a3, D. Kiefer^a1a2, D. Jung^a2a4, X.Q. Yan^a1a5, T. Tajima^a2a6, J. Schreiber^a1a2, M. Hegelich^a2a4, P.V. Nickles^a3a7, M. Zepf^a1a8, G.D. Tsakiris^a1, W. Sandner^a3 and D. Habs^a1a2

^a1 Max-Planck-Institut für Quantenoptik, Garching, Germany

^a2 Fakultät für Physik, Ludwig-Maximilians-Universität München, Garching, Germany

^a3 Max-Born-Institut, Berlin, Germany

^a4 Los Alamos National Laboratory, Los Alamos, New Mexico

^a5 State Key Lab of Nuclear Physics and Technology, Peking University, Bejing, China

^a6 Photomedical Research Center, JAEA, Kyoto, Japan

^a7 Gwangju Institute of Science and Technology, GIST, Gwangju, Republic of Korea

^a8 Department of Physics and Astronomy, Queens University Belfast, Belfast, United Kingdom

Abstract

In this paper we report on an experimental study of high harmonic radiation generated in nanometer-scale foil targets irradiated under normal incidence. The experiments constitute the first unambiguous observation of odd-numbered relativistic harmonics generated by the v × B component of the Lorentz force verifying a long predicted property of solid target harmonics. Simultaneously the observed harmonic spectra allow in-situ extraction of the target density in an experimental scenario which is of utmost interest for applications such as ion acceleration by the radiation pressure of an ultraintense laser.

(Received June 17 2011)

(Accepted July 20 2011)

Keywords

• Frequency conversion;
• Laser-driven acceleration;
• Laser-plasma interaction;
• Particle-in-cell method;
• Plasma-generated coherent radiation

Correspondence:

^c1 Address correspondence and reprint requests to: S. Steinke, Max-Born-Institut, D-12489 Berlin, Germany. E-mail: steinke@mbi-berlin.de