Techniques for soft x‐ray absorption in laser‐produced plasmas

Interest in x‐ray absorption derives from soft x‐ray transport studies to characterize laser‐solid‐interaction effects. The object of this work was to determine whether x‐ray absorption features were measurable in laser‐produced plasmas from solid targets. X‐ray emission was made using high‐atomic‐number microsphere targets irradiated with a focused beam of the Pharos laser while the laser‐solid‐interaction plasmas were generated by a second beam in Al foil targets. High‐resolution, spatially resolved x‐ray spectra were collected with instrumentation and geometry similar to previous tracer‐dot spectroscopy measurements of plasma profile parameters. Soft x‐ray absorption lines, observed at different distances from the aluminum target surface, may be related to density gradients in the laser‐generated plasmas.