Mocker Anna, Bugiel Sebastian, Auer Siegfried, Baust Günter, Colette Andrew, Drake Keith, Fiege Katherina, Grün Eberhard, Heckmann Frieder, Helfert Stefan, Hillier Jonathan, Kempf Sascha, Matt Günter, Mellert Tobias, Munsat Tobin, Otto Katharina, Postberg Frank, Röser Hans-Peter, Shu Anthony, Sternovsky Zoltán, Srama Ralf
IRS, Universität Stuttgart, Pfaffenwaldring 31, D-70569 Stuttgart, Germany.
Rev Sci Instrum. 2011 Sep;82(9):095111. doi: 10.1063/1.3637461.
Investigating the dynamical and physical properties of cosmic dust can reveal a great deal of information about both the dust and its many sources. Over recent years, several spacecraft (e.g., Cassini, Stardust, Galileo, and Ulysses) have successfully characterised interstellar, interplanetary, and circumplanetary dust using a variety of techniques, including in situ analyses and sample return. Charge, mass, and velocity measurements of the dust are performed either directly (induced charge signals) or indirectly (mass and velocity from impact ionisation signals or crater morphology) and constrain the dynamical parameters of the dust grains. Dust compositional information may be obtained via either time-of-flight mass spectrometry of the impact plasma or direct sample return. The accurate and reliable interpretation of collected spacecraft data requires a comprehensive programme of terrestrial instrument calibration. This process involves accelerating suitable solar system analogue dust particles to hypervelocity speeds in the laboratory, an activity performed at the Max Planck Institut für Kernphysik in Heidelberg, Germany. Here, a 2 MV Van de Graaff accelerator electrostatically accelerates charged micron and submicron-sized dust particles to speeds up to 80 km s(-1). Recent advances in dust production and processing have allowed solar system analogue dust particles (silicates and other minerals) to be coated with a thin conductive shell, enabling them to be charged and accelerated. Refinements and upgrades to the beam line instrumentation and electronics now allow for the reliable selection of particles at velocities of 1-80 km s(-1) and with diameters of between 0.05 μm and 5 μm. This ability to select particles for subsequent impact studies based on their charges, masses, or velocities is provided by a particle selection unit (PSU). The PSU contains a field programmable gate array, capable of monitoring in real time the particles' speeds and charges, and is controlled remotely by a custom, platform independent, software package. The new control instrumentation and electronics, together with the wide range of accelerable particle types, allow the controlled investigation of hypervelocity impact phenomena across a hitherto unobtainable range of impact parameters.
研究宇宙尘埃的动力学和物理性质能够揭示大量有关尘埃及其众多来源的信息。近年来，几艘航天器（如卡西尼号、星尘号、伽利略号和尤利西斯号）已使用包括原位分析和样本返回在内的多种技术成功地对星际、行星际和环行星尘埃进行了表征。尘埃的电荷、质量和速度测量可直接进行（感应电荷信号）或间接进行（通过撞击电离信号或撞击坑形态得出质量和速度），并能确定尘埃颗粒的动力学参数。尘埃成分信息可通过撞击等离子体的飞行时间质谱法或直接样本返回获得。对收集到的航天器数据进行准确可靠的解读需要一个全面的地面仪器校准计划。这个过程包括在实验室中将合适的太阳系模拟尘埃颗粒加速到超高速，这项活动在德国海德堡的马克斯·普朗克核物理研究所进行。在这里，一台2兆伏的范德格拉夫加速器通过静电将带电的微米级和亚微米级尘埃颗粒加速到高达80千米/秒的速度。尘埃生产和处理方面的最新进展使得太阳系模拟尘埃颗粒（硅酸盐和其他矿物）能够被涂上一层薄导电壳，从而能够被充电和加速。束线仪器和电子设备的改进与升级现在使得能够可靠地选择速度在1至80千米/秒之间、直径在0.05微米至5微米之间的颗粒。这种根据颗粒的电荷、质量或速度选择颗粒用于后续撞击研究的能力由一个颗粒选择单元（PSU）提供。该PSU包含一个现场可编程门阵列，能够实时监测颗粒的速度和电荷，并由一个定制的、与平台无关的软件包进行远程控制。新的控制仪器和电子设备，连同可加速的多种颗粒类型，使得能够在一个迄今无法实现的撞击参数范围内对超高速撞击现象进行可控研究。
