条纹相机在真空弧离子源等离子体诊断中的应用

针对真空弧离子源,利用条纹相机将时间轴信息转换为空间轴信息的特点,结合光谱仪分光功能,建立了一套高时间分辨与光谱分辨能力的发射光谱诊断装置,其时间分辨率和光谱分辨率分别可达26ps与0.1nm。利用该诊断装置采集获得了单次脉冲内等离子体的时间演化特性;同时,基于局域热力学平衡等离子体的发射光谱理论,建立了一套谱线拟合的等离子体温度与密度计算模型。相比传统的Boltzmann斜率法与Stark展宽法需要寻找孤立的不受附近谱线叠加的干净线状光谱,建立的拟合光谱模型可以直接处理多条谱线因为展宽效应而叠加形成的光谱线型,计算得到等离子体中电子温度与电子密度。结果表明,在脉冲功率源的作用下,真空弧放电等离子体的电子温度与电子密度分别可达1eV与3.5×1024 m-3。

Application of a streak camera to diagnosis of plasma in vacuum arc ion source

In order to study the vacuum arc ion source, using a streak camera which could transform the temporal signal to spatial signal, and a spectrograph which could separate an incoming wave into a frequency spectrum, we built a time resolution of plasma optical emission spectra diagnosis experiment platform, and measured the time- and spectral-resolution of this diagnosis system, with a time-resolution of 26 ps, and a spectral-resolution of 0.1 nm. Based on this diagnosis system, the temporal evolution of the plasma and the optical emission spectra were acquired in an only one pulse. At the same time, based on the emission spectra theory of the local thermodynamic equilibrium plasma, we established an emission spectra model, and performed the fitting of the emission spectra of experimental plasma spectra to obtain the temporal evolution of the electron temperature and electron density in plasma. Different from conventional Blotzmann plot and Stark broadening methods needed the isolated line, the fitting model established in this work could deal with the overlapped lines due to broadening. The calculated electron temperature and density were about 1 eV and 3.51024 m-3 respectively.