An experimental research platform is built on Shenguang II high power laser facility for obtaining the equation of state of liquid deuterium which has ability to control the temperature in a range of 12–300 K with an accuracy of ±0.03 K in 80 min. By optimizing the coating processing and cleaning the target, we solve the problems that the residual reflection is too high and serious frosting takes place on the window of the target at low temperature, then we obtain the experimental image with a good signal-to-noise ratio. By using the impedance matching method and velocity interferometer system for any reflector, experimental Hugoniot data of liquid deuterium are obtained at a pressure of about 60 GPa under the output condition of 3ω, 3 ns, 1200 J on Shenguang II high power laser, which agrees well with the other published data in the same pressure regime and provides a good foundation for the next experimental study of liquid deuterium equation in 100 GPa pressure regime.

The coupling efficiency of short-pulse ignition laser energy to hot-spot internal energy directly affects the feasibility of fast ignition. Experimental characterization of the hot spot has attracted much attention. Among temperature, density and neutron yield of fast ignition experiments, the temperature of the hot spot has few available diagnostic methods. Multispectral X-ray imaging of hot-spot continuum emission is expected to give the time evolution of the electron temperature distribution. This article describes electron temperature determination from multispectral imaging, a dual-channel X-ray Kirkpatrick-Baez (KB) microscope designed for two-spectral imaging, and the experimental results of hot-core multispectral imaging of an imploded cone-shell target at the SG-II laser facility.

The X-ray spectrometer used in high-energy-density plasma experiments generally requires both broad X-ray energy coverage and high temporal, spatial, and spectral resolutions for overcoming the difficulties imposed by the X-ray background, debris, and mechanical shocks. By using an elliptical crystal together with a streak camera, we resolve this issue at the SG-II laser facility. The carefully designed elliptical crystal has a broad spectral coverage with high resolution, strong rejection of the diffuse and/or fluorescent background radiation, and negligible source broadening for extended sources. The spectra that are Bragg reflected (23°<θ<38°) from the crystal are focused onto a streak camera slit 18 mm long and about 80 μm wide, to obtain a time-resolved spectrum. With experimental measurements, we demonstrate that the quartz(1011) elliptical analyzer at the SG-II laser facility has a single-shot spectral range of (4.64–6.45) keV, a typical spectral resolution of E/DE = 560, and an enhanced focusing power in the spectral dimension. For titanium (Ti) data, the lines of interest show a distribution as a function of time and the temporal variations of the He-a and Li-like Ti satellite lines and their spatial profiles show intensity peak red shifts. The spectrometer sensitivity is illustrated with a temporal resolution of better than 25 ps, which satisfies the near-term requirements of high-energy-density physics experiments.

It is important to diagnose electron density of a plasma irradiated by lasers for inertial confinement fusion, in high energy density physics and related fields, especially for measuring high-Z plasma near the interface. Use of soft X-ray laser as a probe is an important method in diagnosis of plasma electron density distribution. However, it is difficult to carry out the research in high-Z laser plasma, because of the problem of excessive plasma spontaneous radiation. In view of the characteristics of soft X-ray laser, several specific experimental techniques have been developed. By using these techniques, which can greatly suppress effects of spontaneous radiation, diagnosis of high-Z plasma with soft X-ray laser probe method becomes possible. As a typical example, an experiment of diagnosing gold plasma is performed and clear images are obtained, indicating that the techniques are effective and feasible.

The diagnoses of laser-produced plasma electron density have important significance for inertial confinement fusion, plasma physics, high energy density physics and other relevant fields, especially for measuring electron density distribution information of medium and high-Z material plasma near the critical density surface. With 13.9 nm Ni-like Ag X-ray laser serving as a probe, using double frequency grating shearing interference technique, the electron density distribution of plasma produced by laser irradiating a gold planar target is measured. Clear interference fringe image is obtained. Preliminary deduction of the fringe shows that the maximum density measured is about 1.4 times the critical density. It is found that there are some discrepancies between experimental results and simulation results, which provides a useful reference to the further optimization of the simulation program. The experimental results fully demonstrate that the soft X-ray double frequency grating shearing interference technique is practical to diagnose near-critical-density plasma of medium and high-Z materials, which will have a good application value.

A joint diagnostic system was established for the diagnosis of laser-driven shock wave experiments. The system has high temporal resolution (time resolution ～12 ps) and high spatial resolution (spatial resolution ～7 μm) and fits for diagnostics of the experiment with small sample size and short time physical process. The joint diagnostic system was applied for shock wave measurement on the Shenguang-II laser facility. The passive shock breakout signal and active diagnostic signal were simultaneously obtained. The temporal measurement reliability of the system was verified using a multi-layered target. The experimental results show that the two measurement results were consistent.

The supersonic jets and the interaction of strong shock waves are ubiquitous features of the nonlinear hydrodynamics of inertial-confinement fusion, astrophysic, and related fields of high energy-density science, so very important value have their studies in laboratory. A laboratories experimental study on jets is reported. The plasma jets were created by an ns laser pulse irradiating a special circular hole target, and the shadow of jets were recorded by using an X-ray laser probe with wavelength of 13.9 nm. Legible shadow images of plasma jets were obtained. The experimental results and theoretical simulation were in qualitative agreement.

报道了在20TW皮秒激光器上完成的p偏振激光与等离子体相互作用过程中产生的快电子的角分布和能谱测量结果.实验得到:当激光功率密度小于10¹⁷ W/cm²时,电子发射没有明显定向性,在激光入射面内多峰发射;当激光功率密度大于10¹⁷ W/cm²,小于10¹⁸ W/cm²时,电子主要沿靶面法线方向发射;当激光功率密度达到相对论强度时,电子主要沿激光传播方向发射;激光功率密度未达到相对论强度时,靶后表面法线方向快电子能谱拟合平均温度符合共振吸收温度定标率;激光功率密度达相对论强度以上时,靶后表面法线方向快电子能谱拟合平均温度高于已有的温度定标率.