We report the experimentally determined angular distribution of the [1s2s(2)2p(1/2)](1)→[1s(2)2s(2)](0) transition in dielectronic recombination of Li-like Au. Recently, Fritzsche et al. [Phys. Rev. Lett. 103, 113001 (2009)] predicted that the Breit interaction plays a dominant role in the angular distribution of this transition. However, the predicted phenomenon has not yet been observed experimentally due to technical difficulties in conventional methods. To overcome the difficulties, we combine two different measurements with an electron beam ion trap (EBIT) to obtain the x-ray angular distribution. One is the x-ray measurement at 90° and another is the integral resonant strength measurement through the ion charge abundance in the EBIT. Our measurements agree well with the theoretical prediction and confirm the dominance of the Breit interaction.

In this paper, we give a review of our theoretical and experimental progress in octahedral spherical hohlraum study. From our theoretical study, the octahedral spherical hohlraums with 6 Laser Entrance Holes (LEHs) of octahedral symmetry have robust high symmetry during the capsule implosion at hohlraum-to-capsule radius ratio larger than 3.7. In addition, the octahedral spherical hohlraums also have potential superiority on low backscattering without supplementary technology. We studied the laser arrangement and constraints of the octahedral spherical hohlraums, and gave a design on the laser arrangement for ignition octahedral hohlraums. As a result, the injection angle of laser beams of 50°–60° was proposed as the optimum candidate range for the octahedral spherical hohlraums. We proposed a novel octahedral spherical hohlraum with cylindrical LEHs and LEH shields, in order to increase the laser coupling efficiency and improve the capsule symmetry and to mitigate the influence of the wall blowoff on laser transport. We studied on the sensitivity of the octahedral spherical hohlraums to random errors and compared the sensitivity among the octahedral spherical hohlraums, the rugby hohlraums and the cylindrical hohlraums, and the results show that the octahedral spherical hohlraums are robust to these random errors while the cylindrical hohlraums are the most sensitive. Up till to now, we have carried out three experiments on the spherical hohlraum with 2 LEHs on Shenguang(SG) laser facilities, including demonstration of improving laser transport by using the cylindrical LEHs in the spherical hohlraums, spherical hohlraum energetics on the SGIII prototype laser facility, and comparisons of laser plasma instabilities between the spherical hohlraums and the cylindrical hohlraums on the SGIII laser facility.

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Unique high-capacity MnO2/porous graphitic carbon (MnO2/PGC) composites were fabricated by a mild and efficient in situ precipitation approach using PGC derived from coal tar pitch as the carbonaceous precursor and KMnO4 as the manganese source. MnO2/PGC composites with reasonable surface areas (190–229 m2 g–1) retain the superior structure of interconnected nanopores and graphitic crystallite from PGC and contain evenly distributed MnO2 modified on the surface of the carbon skeleton in PGC, which can not only provide sufficient active sites for lithium-ion storage but also enhance electron transport capability and efficient lithium-ion diffusion capability. As a result of the synergistic effect of PGC and MnO2, MnO2/PGC composites as anode materials in lithium-ion batteries (LIBs) exhibit excellent reversible capacity, rate performance, and cycling stability. In particular, the MnO2/PGC-36 composite possesses a high initial reversible capacity of 1516 mAh g–1 at a current density of 0.05 A g–1 and an average reversible capacity of 399 mAh g–1 at a high rate of 5.00 A g–1. Moreover, such a MnO2/PGC-36 composite also exhibits a superior long-term cycling stability, with over 90.0% capacity retention after 400 cycles. These outstanding electrochemical performances demonstrate that the MnO2/PGC composite can be a promising anode material in LIBs for further practical application.

The high-energy electron impact excitation cross sections are directly proportional to the generalized oscillator strengths ͑GOSs͒ of the target ͑an atom or molecule͒. In the present work, the GOSs of helium from the ground state to n 1 S, n 1 P, n 1 D ͑n → ϱ͒ and adjacent continuum excited states are calculated by a modified R-matrix code within the first Born approximation. In order to treat the bound-bound and bound-continuum transitions in a unified manner, the GOS density ͑GOSD͒ is defined based on the quantum defect theory. The GOSD surfaces of 1 S, 1 P, and 1 D channels are calculated and tested stringently by the recent experiments. With the recommended GOSD surfaces with sufficient accuracy, the GOSDs ͑i.e., GOSs͒ from the ground state into all n 1 S, n 1 P, and n 1 D excited states of helium can be obtained by interpolation. Thus, the high-energy electron impact excitation cross sections of all these excited states can be readily obtained. In addition to the high-energy electron impact excitation cross sections, a scheme to calculate the cross sections in the entire incident energy range is discussed.