Picture of wind turbine against blue sky

Open Access research with a real impact...

The Strathprints institutional repository is a digital archive of University of Strathclyde research outputs.

The Energy Systems Research Unit (ESRU) within Strathclyde's Department of Mechanical and Aerospace Engineering is producing Open Access research that can help society deploy and optimise renewable energy systems, such as wind turbine technology.

Explore wind turbine research in Strathprints

Explore all of Strathclyde's Open Access research content

High harmonics from relativistically oscillating plasma surfaces : a high brightness attosecond source at keV photon energies

Zepf, M. and Dromey, B. and Kar, S. and Bellei, C. and Carroll, D.C. and Clarke, R.J. and Green, J.S. and Kneip, S. and McKenna, P. (2007) High harmonics from relativistically oscillating plasma surfaces : a high brightness attosecond source at keV photon energies. Plasma Physics and Controlled Fusion, 49 (12B). B149-B162. ISSN 0741-3335

Full text not available in this repository. (Request a copy from the Strathclyde author)

Abstract

An intense laser pulse interacting with a near discontinuous plasma vacuum interface causes the plasma surface to perform relativistic oscillations. The reflected laser radiation then contains very high order harmonics of fundamental frequency and-according to current theory-must be bunched in radiation bursts of a few attoseconds duration. Recent experimental results have demonstrated x-ray harmonic radiation extending to 3.3 angstrom (3.8 keV, order n > 3200) with the harmonic conversion efficiency scaling as eta(n) n(-2.5) over the entire observed spectrum ranging from 17 nm to 3.3 angstrom. This scaling holds up to a maximum order, n(RO) 81 8(1/2)gamma(3), where gamma is the peak value of the Lorentz factor, above which the harmonic efficiency decreases more rapidly. The coherent nature of the generated harmonics is demonstrated by the highly directional beamed emission, which for photon energy h nu > 1 keV is found to be into a cone angle similar to 4 degrees, significantly less than that of the incident laser cone (20 degrees).