C III density diagnostics in nonequilibrium plasmas
C III density diagnostics in nonequilibrium plasmas
复制标题
非平衡等离子体中的 C III 密度诊断
DOI：
10.1086/156151
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发表时间：
1978
期刊：
影响因子：
--
通讯作者：
A. Dupree
中科院分区：
文献类型：
--
作者：
J. Raymond;A. Dupree
通过温度梯度的质量流可以产生电离态从其平衡值的实质性偏离，并且可以改变线发射的特征。铍序列离子C III，这是一个容易观察到的和强大的诊断碰撞为主的等离子体中的电子密度在太阳大气中的极紫外线强度的影响，这样的流量进行评估。过渡区的物质向下流动会导致低估电子密度;物质外流，如恒星风或太阳风从色球温度到日冕温度，产生可靠的密度诊断。在紫外线发射谱线的分析中的模糊性可以通过测量几个跃迁来避免。
Mass flow through a temperature gradient can produce substantial departures of the ionization states from their equilibrium values and can change the character of line emission. The effect of such flows on extreme ultraviolet intensities in the solar atmosphere is evaluated for the beryllium-sequence ion C III, which is an easily observed and powerful diagnostic of electron density in a collisionally dominated plasma. A downflow of material in a transition region can lead to an underestimate of the electron density; outflow of material, as in a stellar or solar wind passing from chromospheric to coronal temperatures, yields a reliable density diagnostic. Ambiguities in the analysis of ultraviolet emission lines can be circumvented by measurement of several transitions.