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Electron collection by an electrodynamic bare tether at high potential
| Content Provider | Semantic Scholar |
|---|---|
| Author | Ferry, Jean-Benoît |
| Copyright Year | 2003 |
| Abstract | In tethered satellites, it is very important to be able to estimate the electron current collected by the tether. However, this analysis is very difficult because of the presence of the geomagnetic field. We are developing a Particle-In-Cell model. The model uses a boundary condition based on quasi-neutrality, very similar to the one T. Onishi used in his Ph.D Thesis (2002), in order to solve for the local potential at the points of the computational boundary. This condition imposes ne = ni at the boundary. Moreover the motion of particles is computed analytically in a domain close to the tether inside the sheath. This calculation is made possible by neglecting the space charge effect, which is very small in comparison with the tether potential, and therefore allowing the Laplace equation to be solved. The goal of this analytical domain is to provide a better accuracy in the region where electrons can reach high velocity. Although a similar approach was used by T. Onishi, the goal of this model is to experiment higher voltages for the tether, with bias ratio of the order of 1000 to 2500. Indeed such voltages are the ones of interest for space tethers. In order to be able to reach these voltages, we first conducted a precise analysis of the quiescent un-magnetized case. This analysis allowed us to successfully compare the model with established probe theory results. Moreover it gives a good foundation to explore the more complicated case of a magnetized flowing plasma. Thesis Supervisor: Manuel Martinez-Sanchez Title: Professor Acknowledgments The realisation of this thesis was a long journey. Without the help of many people, I would have never seen the end of the road. First of all I want to thank my parents: they always helped me find the right path, and they always supported me when choices were tough to make. I am also grateful to my advisor, Professor Martinez Sanchez, he was always comprehensive and available when I needed advice. Thanks also to Tatsuo, he helped me very patiently in understanding his huge work on space tethers. Of course this would not have been possible without my officemates, Luis and Murat. They know how to turn a sunless office into a bright and happy place. Last but no least, Nathalie was always here when I needed courage and strength. She always had a smile for me. My stay at MIT would not have been the same without the warmth of her love. |
| File Format | PDF HTM / HTML |
| Alternate Webpage(s) | http://ssl.mit.edu/publications/theses/SM-2003-FerryJean-Benoit.pdf |
| Alternate Webpage(s) | http://dspace.mit.edu/bitstream/handle/1721.1/82762/54069355-MIT.pdf?sequence=2 |
| Language | English |
| Access Restriction | Open |
| Content Type | Text |
| Resource Type | Article |
