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...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 3μm,for characterization of higher-mode signatures such as Ps-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.展开更多
A study is conducted using a two-dimensional simulation program （Lared-s） with the goal of developing a technique to evaluate the effect of Rayleigh-Taylor growth in a neutron fusion reaction region. Two peaks of fu...A study is conducted using a two-dimensional simulation program （Lared-s） with the goal of developing a technique to evaluate the effect of Rayleigh-Taylor growth in a neutron fusion reaction region. Two peaks of fusion reaction rate are simulated by using a two-dimensional simulation program （Lared-s） and confirmed by the experimental results. A neutron temporal diagnostic （NTD） system is developed with a high temporal resolution of - 30 ps at the Shen Guang-Ⅲ （SG-Ⅲ） prototype laser facility in China, to measure the fusion reaction rate history. With the shape of neutron reaction rate curve and the spherical harmonic function in this paper, the degree of Rayleigh-Taylor growth and the main source of the neutron yield in our experiment can be estimated qualitatively. This technique, including the diagnostic system and the simulation program, may provide important information for obtaining a higher neutron yield in implosion experiments of inertial confinement fusion.展开更多
The infrared quantum cutting of oxyfluoride nanophase vitroceramics Tb（0.7）Yb（3）：FOV has been studied in the present paper. The actual quantum cutting efficiency formula calculated from integral fluorescence inte...The infrared quantum cutting of oxyfluoride nanophase vitroceramics Tb（0.7）Yb（3）：FOV has been studied in the present paper. The actual quantum cutting efficiency formula calculated from integral fluorescence intensity is extended to the case of Tb（0.7）Yb（3）：FOV. The visible and the infrared fluorescence spectra and their integral fluorescence intensities are measured from static fluorescence experiment. Lifetime curve is measured from dynamic fluorescence experiment. It is found that the total actual quantum cutting efficiency n of the excited 5D4 level is about 93.7%, and that of excited （5D3, 5G6） levels is 93.5%. It is also found that the total theoretical quantum cutting efficiency upper limit ？~x^Yb of the 485.5 nm excited 5D4 level is about 121.7%, and that of 378.5 nm excited （5D3, 5G6） levels is 137.2%.展开更多
基金National Key R&D Program(No.2017YFA0403204)Laser Fusion Research Funds for Young Talents(No.RCFPD1-2017-1)。
文摘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 3μm,for characterization of higher-mode signatures such as Ps-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.
基金Project supported by the National Natural Science Foundation of China(Grant No.10805041)the Science and Technology on Plasma Physics Laboratory,China(Grant No.9140C6801021001)the Science and Technology Development Foundation of China Academy of Engineering Physics,China(Grant No.2011B0102020)
文摘A study is conducted using a two-dimensional simulation program （Lared-s） with the goal of developing a technique to evaluate the effect of Rayleigh-Taylor growth in a neutron fusion reaction region. Two peaks of fusion reaction rate are simulated by using a two-dimensional simulation program （Lared-s） and confirmed by the experimental results. A neutron temporal diagnostic （NTD） system is developed with a high temporal resolution of - 30 ps at the Shen Guang-Ⅲ （SG-Ⅲ） prototype laser facility in China, to measure the fusion reaction rate history. With the shape of neutron reaction rate curve and the spherical harmonic function in this paper, the degree of Rayleigh-Taylor growth and the main source of the neutron yield in our experiment can be estimated qualitatively. This technique, including the diagnostic system and the simulation program, may provide important information for obtaining a higher neutron yield in implosion experiments of inertial confinement fusion.
基金supported by the National Natural Science Foundation of China (Grant No. 10674019)
文摘The infrared quantum cutting of oxyfluoride nanophase vitroceramics Tb（0.7）Yb（3）：FOV has been studied in the present paper. The actual quantum cutting efficiency formula calculated from integral fluorescence intensity is extended to the case of Tb（0.7）Yb（3）：FOV. The visible and the infrared fluorescence spectra and their integral fluorescence intensities are measured from static fluorescence experiment. Lifetime curve is measured from dynamic fluorescence experiment. It is found that the total actual quantum cutting efficiency n of the excited 5D4 level is about 93.7%, and that of excited （5D3, 5G6） levels is 93.5%. It is also found that the total theoretical quantum cutting efficiency upper limit ？~x^Yb of the 485.5 nm excited 5D4 level is about 121.7%, and that of 378.5 nm excited （5D3, 5G6） levels is 137.2%.
