Title:
Dust Detection by Antenna Instruments
Dust Detection by Antenna Instruments
Time:
12/19 (Sat.) 7 pm PST, 8 pm MST, 9 pm CST, 10 pm EST
12/20 (Sun.) 11 am Taiwan
12/19 (Sat.) 7 pm PST, 8 pm MST, 9 pm CST, 10 pm EST
12/20 (Sun.) 11 am Taiwan
Keywords:
planetary science, cosmic dust, dust detection, antenna instruments, induced charging
planetary science, cosmic dust, dust detection, antenna instruments, induced charging
Abstract:
Space missions often carry antenna instruments that are sensitive to dust impacts, however, the understanding of signal generation mechanisms has been lacking. A signal generation model in an analytical form is presented that provides a good agreement with laboratory simulation measurements. The model is based on direct and induced charging of the spacecraft from the collected and escaping fraction of free charges from the impact-generated plasma cloud. A set of laboratory experiments is performed using a 20:1 scaled-down model of the Cassini spacecraft using a dust accelerator facility. The results show that impact plasmas can be modeled as a plume of ions streaming away from the impact location and a cloud of isotropically expanding electrons. The fitting of the model to the collected antenna waveforms provides the key parameters of impact plasma.
Space missions often carry antenna instruments that are sensitive to dust impacts, however, the understanding of signal generation mechanisms has been lacking. A signal generation model in an analytical form is presented that provides a good agreement with laboratory simulation measurements. The model is based on direct and induced charging of the spacecraft from the collected and escaping fraction of free charges from the impact-generated plasma cloud. A set of laboratory experiments is performed using a 20:1 scaled-down model of the Cassini spacecraft using a dust accelerator facility. The results show that impact plasmas can be modeled as a plume of ions streaming away from the impact location and a cloud of isotropically expanding electrons. The fitting of the model to the collected antenna waveforms provides the key parameters of impact plasma.
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