Parker Solar Probe (PSP) uses Venus gravity assists (VGA) to achieve the closest orbits to the Sun by a spacecraft. During the third (VGA3) and fourth (VGA4) Venus gravity assists, the PSP entered the Venusian ionosphere. The core electrons could not be detected as they were below the SWEAP/SPAN electrostatic analyzer instrument energy threshold. However, there is another way to estimate the core temperature using quasi-thermal noise (QTN) data measured by the PSP/FIELDS Radio Frequency Spectrometer instrument. QTN spectroscopy offers an effective tool for measuring electron temperature and density when the electrons are too cold for other instruments to measure, as is the case with VGA3 and VGA4. Low-frequency plasma wave data from the closest approach during VGA3 and VGA4 was analyzed with the QTN spectroscopy technique to determine the density and first-ever in-situ thermal electron temperature of the Venusian ionosphere at solar minimum.

中文翻译：

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使用准热噪声光谱法从帕克太阳探测器获得金星电离层中的电子温度


帕克太阳探测器 （PSP） 使用金星引力辅助 （VGA） 来实现航天器最接近太阳的轨道。在第三次 （VGA3） 和第四次 （VGA4） 金星重力辅助期间，PSP 进入了金星电离层。由于核心电子低于 SWEAP/SPAN 静电分析仪仪器的能量阈值，因此无法检测到它们。但是，还有另一种方法可以使用 PSP/FIELDS 射频谱仪测量的准热噪声 （QTN） 数据来估计核心温度。QTN 光谱法提供了一种有效的工具，当电子太冷而其他仪器无法测量时，就像 VGA3 和 VGA4 一样。使用 QTN 光谱技术分析了 VGA3 和 VGA4 期间来自最近接近的低频等离子体波数据，以确定金星电离层在太阳极小期的密度和首次原位热电子温度。