Abstract By the line ratio of Oxygen IV 1399.776.50 Å and 1401.163 Å lines in a flare ribbon in the solar transition region, the principle of the electron density diagnostics using the collisional radiative model is discussed, and the relationship of the electron density with the line ratio is obtained, for both Maxwellian and Kappa distributions. By the observed line ratio, the diagnostic result of the electron density in the flare ribbon for the Maxwellian distribution are and at the temperature of K, 5.0 K and 5.17 K, respectively, which are slightly smaller than reported using the method of differential emission measure. The electron density for the Kappa distributions are and for κ = 2, 3 and 5, respectively. With increasing κ, the electron density for the Kappa distribution will be close to that for the Maxwellian distribution. This discussion is significant in the electron density diagnostics in the solar transition region, which will be also important for diagnostics for non-Maxwellian distribution.

中文翻译：

---

使用非麦克斯韦分布的氧 IV 线对耀斑带中电子密度的光谱诊断

摘要 通过太阳跃迁区耀斑带中氧 IV 1399.776.50 Å 和 1401.163 Å 线的线比，讨论了利用碰撞辐射模型进行电子密度诊断的原理，以及电子密度与获得了 Maxwellian 和 Kappa 分布的线比。由观测线比，对麦克斯韦分布的耀斑带中电子密度的诊断结果分别为 K、5.0 K 和 5.17 K 温度下的电子密度，略小于使用差分发射测量方法报告的. Kappa 分布的电子密度分别为 和 κ = 2、3 和 5。随着 κ 的增加，Kappa 分布的电子密度将接近 Maxwellian 分布的电子密度。