A Carbon Nanotube Field Emission Cathode for Electrodynamic Tether Systems

An electrodynamic tether (EDT) is an attractive candidate for deorbit propulsion of future active debris removal systems because of its simplicity and high efficiency in mass and power consumption. EDT needs an electron emission device for sending an electric current to the tether and the device should also be small, simple, and low powered. A field emission cathode (FEC) possesses some advantages on these requirements compared to other cathodes. One of the critical issues on FECs for EDT is the durability on low earth orbit (LEO). We performed a 1500-hour endurance test of a breadboard model of a carbon nanotube FEC at a constant emission current density of 5 mA/cm 2 and a tank pressure of 5 × 10 -5 Pa. The extraction voltage increased from 700 to 1000 V and neither severe breakdown nor short-circuit were observed during the test. The life of the cathode was expected to be much longer than 1500 hours on orbit considering the difference in vacuum conditions between the endurance test and LEO.

[2]  Shin-ichiro Nishida,et al.  Space debris removal system using a small satellite , 2006 .

[3]  Seiji Yamamoto,et al.  Stability of carbon field emission current , 1979 .

[4]  Kenneth A. Dean,et al.  Degradation and failure of carbon nanotube field emitters , 2003 .

[5]  Satomi Kawamoto,et al.  An experimental study on carbon nanotube cathodes for electrodynamic tether propulsion , 2007 .

[6]  Yasushi Ohkawa,et al.  Research and Development of Electrodynamic Tethers for Space Debris Mitigation , 2009 .

[7]  Eduardo Ahedo,et al.  Bare wire anodes for electrodynamic tethers , 1993 .

[8]  Y. Saito,et al.  Field emission from carbon nanotubes and its application to electron sources , 2000 .

[9]  Vlad Hruby,et al.  Testing of Carbon Nanotube Field Emission Cathodes , 2004 .

[10]  Chris Deline,et al.  Field emission cathodes used in the fegi get away special shuttle mission , 2004 .

[11]  M. Walker,et al.  Lifetime and Failure Mechanisms of an Arrayed Carbon Nanotube Field Emission Cathode , 2010, IEEE Transactions on Electron Devices.

[12]  S. Sasaki,et al.  Results from a series of US/Japan tethered rocket experiments , 1986 .

[13]  Yasushi Ohkawa,et al.  Strategy for Active Debris Removal Using Electrodynamic Tether , 2009 .

[14]  R. C. Adamo,et al.  Space Applications of Spindt Cathode Field Emission Arrays , 2000 .

[15]  Jason M. Makela,et al.  Operating Characteristics of a Re-generable Field Emission Cathode for Low-power Electric Propulsion , 2008 .

[16]  Brian E. Gilchrist,et al.  ELECTRON FIELD EMISSION AND THE SPACE CHARGE LIMIT: TECHNIQUES AND TRADEOFFS , 2003 .

[17]  Satomi Kawamoto,et al.  Benefits of Active Debris Removal on the LEO Debris Population , 2010 .

[18]  C. Spindt,et al.  Physical properties of thin‐film field emission cathodes with molybdenum cones , 1976 .

[19]  C. Marrese.  A review of field emission cathode technologies for electric propulsion systems and instruments , 2000, 2000 IEEE Aerospace Conference. Proceedings (Cat. No.00TH8484).

[21]  D. Roach,et al.  Degradation of carbon nanotube field emitters driven by anode adsorbed water , 2008 .

[22]  N. Stone,et al.  Electrodynamic characteristics of the Tethered Satellite System during the TSS-1R mission , 1996 .