TIME RESOLVED SOFT-X-RAY IMAGING WITH SUBMICRON SPATIAL-RESOLUTION (INVITED)

Recent progress in multilayered mirror technology has allowed the developments of novel imaging systems for probing of high density plasmas in the soft x-ray regime. The experimental system described here basically consists of a spherical multilayered mirror which reflects a narrow band (-/+5 eV) of soft x-ray radiation in the 50 to 200 eV energy region. The mirror images either the self-emission of a laser produced plasma and/or the shadow of the expanding plasma generated by a separate laser produced x-ray source with approximately 50X magnification in the image plane and submicron resolution in the target plane. The time resolution of about 150 ps is obtained with either a gated microchannel plate intensifier as detector or a short pulse x-ray backlighter. This imaging technique has been applied to several different studies of laser produced plasmas. Measurements of the overdense plasma profiles were carried out by imaging the self-emission produced by bremsstrahlung. Two-dimensional x-ray radiographs of the density region close to the ablation surface of laser irradiated targets were recorded to observe the uniformity of the overdense plasma blowoff. The hydrodynamics of thin foil targets driven with either laser or soft x-ray radiation was investigated.