标题： 盖尔伽朵尘埃探测器传感器特性的分析——以木星尘埃流粒子为研究对象 显示英文标题

标题： Analysis of the sensor characteristics of the Galileo dust detector with collimated Jovian dust stream particles

摘要： 伽利略号飞船搭载的尘埃探测系统记录了木星系中的尘埃撞击事件。这些撞击事件被分为四个质量等级。第三类——我们最高质量的类别——始终没有噪声干扰，因此只包含真实的尘埃撞击。根据噪声环境的不同，第二类可能是尘埃撞击或者是噪声。在距离木星（木星半径为$R_J = 71,492 km$）$20 R_J$范围内，第二类显示出明显的噪声污染迹象。我们分析了伽利略号木星主任务期间（1996年和1997年）的尘埃数据，区分了尘埃撞击和噪声事件，并获得了伽利略号尘埃数据的完整去噪集（包括第二类和第三类）。在整个木星系统中检测到的纳米级尘埃粒子流（Grünet al. 1998, JGR, 103, 20011-20022）被用来分析尘埃探测器本身的敏感区域和视场。触发第三类事件的尘埃粒子流的敏感面积为$110 \pm 37 cm^2$。这比第二类撞击事件的总敏感面积（1000平方厘米）小将近一个数量级。相应地，第三类尘埃粒子流的探测器视场从$140^{\circ}$减少到$96^{\circ}$。伽利略号上的磁力计天线和其他仪器显著遮挡了尘埃传感器的视场。我们的分析是对尘埃仪器地面校准的补充，因为实验室无法实现这些粒子的低质量和高速度特性。我们的新结果对木星系统的尘埃分析具有重要意义。 显示英文摘要

摘要： The Dust Detector System onboard Galileo records dust impacts in the Jupiter system. Impact events are classified into four quality classes. Class 3 -- our highest quality class -- has always been noise-free and, therefore, contains only true dust impacts. Depending on the noise environment, class 2 are dust impacts or noise. Within $20 R_J$ from Jupiter (Jupiter radius, $R_J = 71,492 km$) class 2 shows clear indications for contamination by noise. We analyse the dust data from Galileo's prime Jupiter mission (1996 and 1997), separate dust impacts from noise events and derive a complete denoised set of Galileo dust data (class 2 and class 3). Collimated streams of nanometer-sized dust particles which have been detected throughout the Jovian system (Gr\"un et al. 1998, JGR, 103, 20011-20022) are used to analyse the sensitive area and the field of view of the dust detector itself. The sensitive area for stream particles which trigger class 3 events is $110 \pm 37 cm^2$. This is almost a factor of ten smaller than the total sensitive area for class 2 impacts (1,000 cm^2). Correspondingly, the field of view of the detector for class 3 stream particles is reduced from $140^{\circ}$ to $96^{\circ}$. The magnetometer boom and other instruments on board Galileo cause a significant shadowing of the field of view of the dust sensor. Our analysis is supplementary to ground calibrations of the dust instrument because the low masses and high speeds of the stream particles could not be achieved in the laboratory. Our new results have important consequences for the analysis of dust in the Jupiter system.