Enhancement of x-ray sources from laser-produced plasmas is significant in wide-ranging applications. Solid and foam TiO2 targets were both used to generate bright x-ray sources at the Shenguang-III ...prototype laser facility, with a total laser power of 3.2 TW. The new foam targets were with an ultra-low initial density of 8.1 mg/cm3 and a high Ti fraction of 33 sat. %. By absolute measurements, the multi-keV x rays of the 4 keV–7 keV band and 1.6 keV–4.4 keV band and the total x rays above 0.1 keV of the foam target have simultaneously shown conversion enhancements of 1.4, 3.1, and 2.3 times, respectively, compared with the solid target. A much larger emission volume and an average electron temperature of 3.2 keV by moving the foci of laser beams inner were obtained for the foam target, providing a good condition for multi-keV x-ray production.
A high-neutron yield platform imploded by a thin shell target is generally built to probe nuclear science problems, and it has the advantages of high neutron yield, ultrashort fusion time, micro ...fusion zone, isotropic and monoenergetic neutron. Some analytical models have been proposed to interpret exploding-pusher target implosion driven by a long wavelength laser, whereas they are imperfect for a 0.35 μm laser implosion experiment. When using the 0.35 μm laser, the shell is ablated and accelerated to high implosion velocity governed by Newton’s law, ablation acceleration and quasi-adiabatic compression models are suitable to explain the implosion of a laser direct-drive thin shell target. The new analytical model scales bang time, ion temperature and neutron yield for large variations in laser power, target radius, shell thickness, and fuel pressure. The predicted results of the analytical model are in agreement with experimental data on the Shenguang-III prototype laser facility, 100 kJ laser facility, Omega, and NIF, it demonstrates that the analytical model benefits the understanding of experiment performance and optimizing the target design of high neutron yield implosion.
Fabrication of an ultrathin solid electrolyte with high conductance is essential to achieve high energy density of solid-state batteries. As solid polymer electrolytes (SPEs) are characterized by ...good ductility, ease of manufacturing, and low cost, the current solvent-based casting pathway suffers from the difficulty in controlling the thickness. In addition, the low ionic conductivity and narrow electrochemical window of the polyether-type SPEs further hinder their practical applications. We fabricate an ultra-thin solid-polymer electrolyte by in situ polymerization of carbonate ester vinyl ethylene carbonate and poly(ethylene glycol) diacrylate using a porous polypropylene membrane as a support. The obtained solid electrolyte is of only 8
μ
m and possesses an unprecedented ionic conductance of 83.3 mS at room temperature. Furthermore, the electrolyte is compatible with Li metal and can suppress dendrite growth. An all-solid-state lithium battery based on LiFePO
4
cathode can operate stably for over 150 cycles with 86% capacity retention. The non-fluidic nature of the electrolyte further enables the fabrication of an energy-dense 24 V bipolar pouch cell which demonstrates extreme flexibility and safety. No voltage drop is observed upon folding and cutting. This in situ polymerized ultra-thin electrolyte provides a promising platform for the fabrication of high-energy solid-state batteries and also a potential candidate for flexible batteries.
Abstract The extreme fast charging performance of lithium metal batteries (LMBs) with a long life is an important focus in the development of next‐generation battery technologies. The friable solid ...electrolyte interphase and dendritic lithium growth are major problems. The formation of an inorganic nanocrystal‐dominant interphase produced by preimmersing the Li in molten lithium bis(fluorosulfonyl)imide that suppresses the overgrowth of the usual interphase is reported. Its high surface modulus combined with fast Li + diffusivity enables a reversible dendrite‐proof deposition under ultrahigh‐rate conditions. It gives a record‐breaking cumulative plating/stripping capacity of >240 000 mAh cm −2 at 30 mA cm −2 @30 mAh cm −2 for a symmetric cell and an extreme fast charging performance at 6 C for 500 cycles for a Li||LiCoO 2 full cell with a high‐areal‐capacity, thus expanding the use of LMBs to high‐loading and power‐intensive scenarios. Its usability both in roll‐to‐roll production and in different electrolytes indicating the scalable and industrial potential of this process for high‐performance LMBs.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Abstract
To achieve ignition in a laboratory via inertial confinement fusion, a spherical capsule containing a frozen layer of deuterium and tritium (DT) fuel will be imploded on an MJ-class laser ...facility. However, if pure deuterium fuel can be used in place of DT fuel for tuning shots, we may speed up the process of ignition experiments while maintaining the surrogacy by significantly reducing the level of radioactivity. Unfortunately, it has long been assumed that neither the approach of symmetrical infrared irradiation used in the Omega direct-drive experiments nor the method of beta-layering used in the NIF experiments can be used to smooth the D layered capsule in cylindrical hohlraums. The difficulty in smoothing the D ice layer prevents us from taking advantage of cryogenic D-layered capsules in indirect-drive experiments. In this work, we established a procedure to form a uniform D-ice layer for capsules held in cylindrical hohlraums and carried out indirect-drive cryogenic D-layered implosion experiments using a squared laser pulse on the Shenguang Laser Facility in China. The quality of the D ice layer is characterized by phase-contrast imaging. The root-mean-square of the power spectrum in modes 2–100 is about 2.2
μ
m. The implosion performance of the D-layered capsules is close to the prediction of one-dimensional simulations. The measured neutron yield and areal fuel density are 1.2 × 10
11
and 80 mg cm
−2
, respectively.
In inertial confinement approaches to fusion, the asymmetry of target implosion is a major obstacle to achieving high gain in the laboratory. A recently proposed octahedral spherical hohlraum makes ...it possible to naturally create spherical target irradiation without supplementary symmetry control. Before any decision is made to pursue an ignition-scale laser system based on the octahedral hohlraum, one needs to test the concept with the existing facilities. Here, we report a proof-of-concept experiment for the novel octahedral hohlraum geometry on the cylindrically configured SGIII laser facility without a symmetry control. All polar and equatorial self-emission images of the compressed target show a near round shape of convergence ratio 15 under both square and shaped laser pulses. The observed implosion performances agree well with the ideal spherical implosion simulation. It also shows limitations with using the existing facilities and adds further weight to the need to move to a spherical port geometry for future ignition laser facilities.
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CMK, CTK, FMFMET, IJS, NUK, PNG, UL, UM
Implosion asymmetry is a crucial problem quenching ignition in the field of inertial confinement fusion. A forward-calculation method based on 1D and 2D hydrodynamic simulations has been developed to ...generate and study the x-ray images of hot-spot self-emission, indicating asymmetry integrated over the entire drive pulse. It is shown that the x-ray imaging photon energy should be higher to avoid the influence of the remaining shell. The contour level (percentage of the maximum emission intensity) and spatial resolution should be as low as possible, optimally less than 20% and 3 µm, for characterization of higher-mode signatures such as P8-P12 by x-ray self-emission images. On the contrary, signatures of lower-mode such as P2 remain clear at all contour levels and spatial resolutions. These key results can help determine the optimal diagnostics, laser, and target parameters for implosion experiments. Recent typical hot-spot asymmetry measurements and applications on the Shenguang 100 kJ class laser facility are also reported.
Coating protection is one of the simplest and most effective measures to protect concrete. Effect of polymer to cement ratio (p/c) on seawater corrosion resistance of polymer modified cementitious ...coatings (PMCC) is investigated base on bond strength, tensile strength, elongation at break and flexural strength tests. The results show that optimal p/c is 0.6. After seawater corrosion, retention rate of bond strength, tensile strength, elongation at break and flexural strength reach 88.44%, 82.74%, 90.56% and 98.6%, respectively.
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