Developing physicotechnical basis for extending service life of the second-generation stationary plasma thrusters

The paper presents results of the joint work of the Moscow Aviation Institute and EDB Fakel to develop physicotechnical basis for extending service life of stationary plasma thrusters (SPT) and demonstrates that the location of the acceleration zone with the major voltage drop is closely linked to the area with the maximum values of the magnetic induction on the midsurface of the acceleration channel in the SPT discharge. It is also demonstrated that using the above link one can shift the acceleration zone from the thruster structure, reducing losses of accelerated ions and their neutralizing electrons on the walls enclosing the acceleration channel, reduce the associated losses of energy and extend the service life of the thruster. Also developed was a baseline structural design for an SPT with a magnetic system containing magnetic screens surrounding the discharge chamber which enables implementing the said shift. That design was implemented in flight models of second-generation SPT, which are successfully operating within motion control systems of spacecraft.