固体电枢电磁轨道发射中, 膛内枢轨滑动电接触的电热特性关系到滑动界面的接触状态、电流传导品质和界面能量耗散, 制约着系统效率和轨道寿命。设计开展了多组不同电流线密度的多发重复试验, 通过采集电气试验数据进行迭代计算, 得到了滑动接触电阻和界面焦耳热耗散功率的动态变化规律, 分析了沉积物随重复发射的演变及电流线密度对电热特性的影响规律, 并结合试验后轨道表面熔蚀沉积检测, 讨论了滑动电接触界面的演变过程。结果表明: 接触电阻稳定临界点和焦耳热耗散功率峰值点都出现在脉冲电流下降沿, 接触电阻稳定值量级为10-2mΩ, 焦耳热功率峰值幅值可达10-1MW；炮口速度随重复次数的增加而降低并趋于稳定, 多次重复发射对滑动接触电阻和焦耳热功率较小的影响表明沉积物在发射中再次熔融并对电接触起积极作用；而即使输入能量一致, 电流线密度的变化也显著影响了界面焦耳热的生成。

An investigation of the cluster size dependence of the maximum energy of protons ejected from explosion of methane clusters in an intense femtosecond laser field has been conducted on the basis of the cluster size estimation by Rayleigh scattering measurements. The interaction of a 2*10^(16)-W/cm2 intense laser pulse (790 nm, 60 fs) with the methane clusters revealed that the clusters were Coulomb exploded and the maximum energy (E_(max)) of the protons produced was linearly proportional to the square of the cluster radius (r_(c)^(2)). In a cluster size range, with the methane cluster radii up to about 3 nm, the established relation of E_(max) and r_(c)^(2) was found to be E_(max) (keV) = 3.3+0.75r_(c)^(2) (nm2), in good agreement with the simulation results. This demonstrated that Coulomb explosion of ionic clusters (C^(+4)H^(+)_(4))_(n) took place following the cluster vertical ionization in the laser-cluster interaction.