Application of soft X-ray lasers for probing high density plasmas

摘要

The reliability and characteristics of collisionally pumped soft x-ray lasers make them ideal for a wide variety of plasma diagnostics. These systems now operate over a wavelength range extending from 35 to 400 (Angstrom) and have output energies as high as 10 mJ in 150 ps pulses. The beam divergence of these lasers is less than 15 mrad and they have a typical linewidth of (Delta)(lambda)/(lambda) (approximately) 10(sup -4) making them the brightest xuv sources available. In this paper we will describe the use of x-ray lasers to probe high density plasmas using a variety of diagnostic techniques. Using an x-ray laser and a multilayer mirror imaging system we have studied hydrodynamic imprinting of laser speckle pattern on directly driven thin foils with 1-2 (mu)m spatial resolution. Taking advantage of recently developed multilayer beamsplitters we have constructed and used a Mach-Zehnder interferometer operating at 155 (Angstrom) to probe 1-3 mm size laser produced plasmas with peak electron densities of 4 x 10(sup 21) cm(sup -3). A comparison of our results with computer simulations will be presented.