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In inertial confinement fusion, electromagnetic pulses (EMPs) can be produced during high-power laser interacting with solid targets, which are intimately related to laser intensity and laser energy. In this study, EMPs generated by hybrid laser pulses coupling with targets are recorded and analyzed. The results indicate that a single picosecond laser gives birth to the most intense EMPs, but they are remarkably suppressed when a nanosecond laser-shooting target is triggered before the picosecond and femtosecond laser. One possible hypothesis is proposed based on x-rays inducing pre-ablation that generates pre-plasma at the surfaces of the picosecond target and femtosecond target, leading to a sharp drop both in the energy and number of the emitting hot electrons and protons. The findings will deepen our understanding of the mechanism of EMPs’ generation and will also open a new avenue to regulate EMPs by hybrid laser pulses.

We have successfully developed a system for deposition of large area diamond films by a DC arc plasma jet operated in gas recycling mode. In the present paper, the influence of substrate temperature, methane concentration, flow rate of feeding gas and the input power of the jet for diamond film deposition is presented. Deposition of a large area of uniform thickness high quality diamond wafer of Φ65 mm in diameter at a growth rate of 15 μm/h is reported. The thickness of the wafer is 0.7 mm and the thermal conductivity can be 18.1 W/cm K.

A procedure has been developed to determine the cut-off frequency in an algorithm to evaluate the localized modulus of elasticity (MOE) in lumber. MOE profiles have been artificially generated to serve as input for evaluation of the procedure. A noise component has also been added to the input record to test the robustness and accuracy of the procedure. Good agreement between program predictions and the known localized MOE values has been obtained. The efficiency of the procedure has also been tested using MOE profiles collected from experiments. The program performed efficiently and program predictions seemed reasonable.