The Rapid Cycling Synchrotron (RCS) of China Spallation Neutron Source (CSNS) includes eight modules of the ferrite kicker magnets with window-frame geometry. The fast extraction kicker system is one of the most important accelerator components, whose inner structure will be the main source of the impedance in the RCS. It is necessary to understand the kicker impedance before its installation into the tunnel. The conventional and improved wire methods are employed for the benchmarking impedance measurement results. The experimental result on the kicker's impedance is explained by comparison with the CST PARTICLE STUDIO simulation. The simulation and measurements confirm that the window-frame ferrite geometry and the end plate are the important structures causing the coupling impedance. It is proved in the measurements that the mismatching among the long cable, the termination and the power form network lead a serious oscillation sideband in the longitudinal and vertical impedance, which can be restricted by the ferrite absorb ring. The total impedance of the eight modules systems is determined by the scaling law from the measurement and the impedance measurement of the kicker system is summarized.

The nonlinear and the exact control of chaos is deduced. Using these methods we achieve a simultaneous and instantaneous control of the scheduled unstable 2 k p points for the logistic and the Henon map. The derivatives needed in the nonlinear method have been evaluated experimentally from the time series x n l without the preknowledge of the function f(x). The difficulty confronted in the optimum control may be overcome by introducing the nonlinear control.

Power balance between laser beams is important for high_power l aser system. This paper uses a calculation method as an exact solution for laser-amplification to simulate the output pulse shape of “Shenguang Ⅱ" laser facility. The results are preferable, as compared with the results of the experiments .

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On the laser driver “Shenguang Ⅱ”, eight fundamental beams have realized power balance. By changing detuning values of parameters of the frequency tripling systems, the output pulse shapes of the output beams are mutually compared. The experiment results indicate that for the type Ⅱ-type Ⅱ polarization-mismatch frequency tripling system, when the input intensity is about 1GW/cm2, of the three parameters that influence the freguency tripling efficiency, polarization detuning angle Δθp has the most important effect on the pulse shape. When all three parameters of tripling system are at the optimized values, the full width at half maximum of pulse shape τ reaches minimum. This work describes the method of crystal adjustment to actualize the power balance of the eight frequency tripling beams.