High-resolution imaging of laser-produced plasmas at a wavelength of 130 A by a normal-incidence multilayer-mirror microscope.

Laser-produced plasmas were imaged by a microscope consisting of spherical, primary, and secondary mirrors in a Cassegrain-type optical configuration. The mirrors were coated with 40 periods of Mo and Si and had a peak reflectance of ∼60% at a wavelength of 130 Å. Nb, Au, and Al targets were irradiated by as many as 24 beams of the Omega laser at the Laboratory for Laser Energetics at the University of Rochester. The images were recorded on Kodak 101 film, and the resolution was limited by the 10-µm emulsion grain size. Two different secondary mirrors produced images with a magnification of 0.8 or 2.2, and a variety of plasma emission features were recorded with 5-µm (0.6-arcsec) resolution in the target plane. The possibility of operating a similar microscope in the wavelength region of 34-50 A is discussed.