The Helicon Double Layer Thruster
The Australian Helicon Double Layer Thruster (HDLT) is a new low-divergence electrode-less magneto-plasma space thruster with extended lifetime, based on the concept of ion acceleration in the potential drop of a current-free electric double layer. Following the discovery of the current-free double layer in a magnetized expanding plasma in 1999, and the subsequent finding of the supersonic large area ion beam downstream of the double layer, the first prototype was fully designed and fabricated in Australia in 2004 and tested at the European Space Agency in 2005. Since late 2006, the SP3 group has been developing the HDLT in collaboration with EADS-ASTRIUM. Recent progress on the HDLT Research and Development includes the study of alternative propellants, the spatial characterisation of the accelerated ion beam, the study of the electron dynamics associated with the double layer formation and the effect of the magnetic and geometric expansion on the double layer and ion beam formation. IRUKANDJI, a new Australian Space Simulation Chamber has been constructed and tested and is now being used for vacuum tests of the HDLT prototypes.