Absolutely measured x-ray spectra from laser plasmas with targets of different elements

Abstract

Soft x-ray spectra emitted by laser-produced plasmas in the wavelength range 10 Å<λ<250 Å were absolutely measured with a transmission grating and calibrated Kodak 101-01 film. Laser pulses with a length of 3 ns and a wavelength of 0.53 μm were focused at an intensity of 3×1013 W/cm2 on planar targets of various elements with atomic numbers ranging from 4 to 82. The overall conversion of incident laser energy into x-ray energy increases from 2% for Be to nearly 50% for the heaviest elements.