Soft X-Ray Laser Interferometry of Colliding Laser-Created Plasmas in Semicylindrical Cavities

A tabletop capillary discharge soft X-ray laser was used to acquire high-contrast interferograms that map the evolution of dense aluminum plasmas created by the laser irradiation of a 500-mum-diameter semicylindrical cavity with 120-ps optical laser pulses of ~1.1 times 10
¹²
- W ldr cm
^-2
peak intensity. The measured electron density maps, which were compared with simulations, show that the plasma converges on axis where it collides to form a localized region with density exceeding 1 times 10
²⁰
cm
^-3
.