中文摘要：

<正> Based on the transmission line code TLCODE,a 1D circuit model for a transmissionlineimpedance transformer was developed and the simulation results were compared with thosein the literature.The model was used to quantify the efficiencies of voltage-transport,energytransportand power-transport for a transmission-line impedance transformer as functions of Ψ(theratio of the output impedance to the input impedance of the transformer)and Γ(the ratio of thepulse width to the one-way transit time of the transformer)under a large scale of m(the coefficientof the generalized exponential impedance profile).Simulation results suggest that with the increasein Γ,from O to ∞,the power transport efficiency first increases and then decreases.The maximumpower transport efficiency can reach 90% or even higher for an exponential impedance profile(m=1).With a consideration of dissipative loss in the dielectric and electrodes of the transformer,tworepresentative designs of the water-insulated transformer are investigated for the next generationof petawatt-class z-pinch drivers.It is found that the dissipative losses in the electrodes arenegligibly small,below 0.1%,but the dissipative loss in the water dielectric is about 1% to 4%.

英文摘要：

Based on the transmission line code TLCODE, a 1D circuit model for a transmission- line impedance transformer was developed and the simulation results were compared with those in the literature. The model was used to quantify the efficiencies of voltage-transport, energy- transport and power-transport for a transmission-line impedance transformer as functions of ψ （the ratio of the output impedance to the input impedance of the transformer） and Г （the ratio of the pulse width to the one-way transit time of the transformer） under a large scale of m （the coefficient of the generalized exponential impedance profile）. Simulation results suggest that with the increase in Г, from 0 to ∞, the power transport efficiency first increases and then decreases. The maximum power transport efficiency can reach 90% or even higher for an exponential impedance profile （m = 1）. With a consideration of dissipative loss in the dielectric and electrodes of the transformer, two representative designs of the water-insulated transformer are investigated for the next generation of petawatt-class z-pinch drivers. It is found that the dissipative losses in the electrodes are negligibly small, below 0.1%, but the dissipative loss in the water dielectric is about 1% to 4%.