Demonstration of transient gain x-ray lasers near 20nm for nickellike yttrium, zirconium, niobium, and molybdenum.

We demonstrate strong lasing on the Ni-like 4d(1)S(0)?4p(1)P(1) transition at 18.9, 20.3, 22.

Demonstration of a neonlike argon soft-x-ray laser with a picosecond-laser-irradiated gas puff target.

We demonstrate a neonlike argon-ion x-ray laser, using a short-pulse laser-irradiated gas puff target. The gas puff target was formed by pulsed injection of gas from a high-pressure solenoid valve through a nozzle in the form of a narrow slit and irradiated with a combination of long, 600-ps and short, 6-ps high-power laser pulses with a total of 10 J of energy in a traveling-wave excitation scheme. Lasing was observed on the 3p (1)S(0)?3s (1)P(1) transition at 46.

X-ray-line diagnostic of magnetic field strength for high-temperature plasmas.

An x-ray line diagnostic for use in magnetic field measurements in high-temperature plasmas has been identified. The intensity of the otherwise strictly forbidden 1s(2)2s(2)2p(1/2)2p(4)(3/2)3s(1/2) 3P0-->1s(2)2s(2)2p(6) 1S0 transition in neonlike ions is shown to depend on the magnetic field strength. The field dependence is illustrated between one and 3 T in the Ar8+ spectrum.

Hot, dense, millimeter-scale, high-Z plasmas for laser-plasma interactions studies.

We have designed and produced hot, millimeter-scale, high-Z plasmas of interest for National Ignition Facility hohlraum target design. Using a high-Z gas fill produces electron temperatures in the 3.5-6-keV range, the highest temperatures measured to date for high-density (10(21) e/cm(3)) laser-heated plasmas, and much higher than the 3 keV found for low-Z (neopentane) fills.

High-power-density capillary discharge plasma columns for shorter wavelength discharge-pumped soft-x-ray lasers.

We report the generation of plasma columns in gas-filled capillary channels using discharge excitation powers that exceed those of previous studies by one to two orders of magnitude. Current pulses up to 200 kA and 10-90 % rise time of about 10 ns (current increase rate equivalent to 1.5 x 10(13) A/s) were utilized to excite plasmas in 3.

Dynamics of a microcapillary discharge plasma using a soft x-ray laser backlighter.

We have used the new technique of soft x-ray laser shadowgraphy in combination with traditional plasma emission spectroscopy and theoretical modeling to study the dynamics of a plasma column created by a discharge through a 380 &mgr;m diameter evacuated microcapillary. The transient microcapillary plasma was imaged with high-spatial and temporal resolution using a tabletop discharge pumped 46.9-nm laser backlighter.

Accuracy of K-shell spectra modeling in high-density plasmas.

We present spectroscopic measurements of the helium-like and lithium-like argon emission supported by Thomson scattering diagnostics on gas bag targets. These data provide critical tests of plasma spectroscopic K-shell models. In particular, we have measured the line radiation in the wavelength region of the He-like Ar 1s(2)-1s3l transition (He-beta) that is of interest for density and temperature measurements of plasmas from gas-filled targets (n(e)/=10(24) cm(-3)).

Gain saturation regime for laser-driven tabletop, transient Ni-like ion X-Ray lasers.

We have demonstrated small signal gain saturation on several transient-gain Ni-like ion x-ray lasers by using a high-power, chirped-pulse amplification, tabletop laser. These results have been achieved at wavelengths from 139-203 A using a total of 5-7 J energy in a traveling-wave excitation scheme. Strong amplification is also observed for Ni-like Sn at 119 A.