Bright source of K[alpha] and continuum X rays by heating Kr clusters using a femtosecond laser
X rays emitted from Kr clusters illuminated by a femtosecond laser have been observed over a wide spectral region from 3 keV to 15 keV. The measured spectra are characterized by a broad bremsstrahlung continuum and K[alpha], [beta] lines at 12.66 keV and 14.1 keV. To the best of the authors' knowledge, this is the first observation of K[alpha], [beta] emission from laser-heated Kr clusters. The bremsstrahlung continuum arising from collisions in the plasma implies a population of hot electrons consistent with a temperature of several kiloelectron volts. The absolute X-ray yield in the 3–15 keV region is found to be of the order of 107 photons per laser pulse. The plasma temperature, estimated from the continuum part of the spectrum as a function of laser intensity and X-ray yield as a function of laser pulse duration, are studied.(Received December 11 2002)
(Accepted April 15 2003)
Key Words: Cluster nanoplasma; Intense lasers; Rare gas clusters; X-ray generation.
c1 Address correspondence and reprint requests to: D.A. Jaroszynski, University of Strathclyde, Department of Physics, John Anderson Building, 107 Rottenrow, Glasgow 0NG, Scotland, United Kingdom. E-mail: email@example.com