Solid Diamond Insulators for Hall Thrusters

The objective of this proposal is to demonstrate greatly extended lifetimes for existing Hall Effect Thruster (HET) designs by using solid diamond components. Polycrystaline diamond is now readily available as an engineering ceramic in sizes suitable foruse in HET's because of the rapid progress made in plasma-assisted Chemical Vapor Disposition. Diamond has many superior chemical and physical properties, most notably thermal conductivity and resistance to sputtering, that make it an ideal choice for theinsulating material of an HET. A notorious problem with Hall Effect Thrusters is that they don't scale down in size efficently. Even thier lifetime reduces out of proportion with size. This improvement would open a whole new catagory of spacecraft to theuse of medium and low power HETs. It has the potentenial to increase the life of high power HETs to the point where they are superior to Ion thruster now used for deep space missions.