Plasma arc thrustor

Claim 2

A thrustor comprising a hollow core, radiatioN means mounted in heat-conducting relation with respect to the core and formed from a material different from the material from which the core is formed, both the radiation means and the core being at the same electrical potential and forming a first electrode, the radiation means and core further defining an outwardly opening cavity into which the hollow portion of the core opens, a second electrode mounted in the hollow portion of the core inwardly from the cavity and having a channel which discharges into the hollow portion of the core for introducing a gaseous propellant into the hollow core, whereby an arc established between the first and second electrodes will pass through the propellant.

Claim 3

A thrustor according to claim 1 wherein the core is provided with two oppositely tapered surfaces, where the radiation means comprises a first radiation flange which embraces one of the tapered surfaces, and a second radiation flange which embraces the other of the tapered surfaces, and wherein means are provided for urging the radiation flanges toward one another and axially with respect to the core, whereby the radiation flanges are maintained on the core and snugly abut the tapered surfaces so that heat conducts readily across the interfaces formed thereby.

Claim 4

A thrustor comprising a hollow core forming a first electrode, injecting means for introducing a gaseous propellant into the hollow core, a second electrode mounted such that an arc established between the first and second electrodes will pass through the propellant introduced into the hollow core, radiation means formed from a material different from the material from which the core is formed, the core and radiation means being in heat-conducting relation with respect to one another, and magnetic field means axially offset with respect to the portion of the second electrode at which the arc attaches.

Claim 5

A thrustor comprising a hollow core forming a first electrode, injecting means for introducing a gaseous propellant into the hollow core, a second electrode mounted such that an arc established between the first and second electrodes will pass through the propellant introduced into the hollow core, radiation means formed from a material different from the material from which the core is formed, the core and radiation means being in heat-conducting relation with respect to one another, and magnetic field means axially offset with respect to the portion of the second electrode at which the arc attaches.

Claim 6

A thrustor according to claim 3 wherein the magnetic field means is an annular coil substantially concentric with respect to the axial centerline of the core.

Claim 7

A thrustor according to claim 4 and further characterized by at least one radiation shield interposed between the coil and radiation means to retard the transference of heat from the radiation means to the coil.

Claim 8

A thrustor according to claim 2 wherein an annular coil is mounted concentric with respect to the axial centerline of the core in axially offset relation to the portion of the second electrode at which the arc initiates, and wherein at least one annular heat shield is interposed between the coil and the second radiation flange whereby to retard radiation of heat from the radiation means to the coil.

Claim 9

A thrustor comprising a hollow core formed from tungsten and serving as a first electrode, radiation means formed from graphite and mounted in intimate contact with the core so that heat is conducted from the core to the radiation means, a substantial surface area on the graphite radiation means being uncovered and exposed outwardly to open space so that the radiation means radiates heat conducted to it away from the thrustor, the core and radiation means being at the same electrical potential, injecting means for introducing a gaseous propellant into the hollow core, and a second electrode mounted such that an arc established between the first and second electrodes will pass through the propellant introduced into the hollow core.

Claim 10

A thrustor comprising a hollow core formed from tungsten and serving as a first electrode, radiation means formed from graphite and mounted in intimate contact with the core so that heat is conducted from the core to the radiation means, a substantial surface area on the graphite radiation means being uncovered and exposed outwardly to open space so that the radiation means radiates heat conducted to it away from the thrustor, the core and radiation means being at the same electrical potential, injecting means for introducing a gaseous propellant into the hollow core, and a second electrode mounted such that an arc established between the first and second electrodes will pass through the propellant introduced into the hollow core.

Claim 11

A thrustor according to claim 7 wherein both the core and the radiation means form the first electrode.

Claim 12

A thrustor comprising a hollow core, an electrode mounted in the hollow core but being electrically isolated therefrom, the electrode being positioned such that an arc will exist between the core and the electrode when a suitable electric potential is impressed across the core and the electrode, injection means for introducing a gaseous propellant into the hollow core such that the propellent flows through the arc, and radiation means surrounding the hollow core and being formed frOm a single material which is a different material than the material from which the core is formed, the radiation means being in intimate contact with the outwardly presented surface of the core for substantially the entire length of and entirely around the core so that heat from the arc will be conducted from the core to the radiation means, the radiation means being uncovered and exposed outwardly to open space so that it radiates the heat conducted through it away from the thrustor.

Claim 13

A thrustor comprising a hollow core, an electrode mounted in the hollow core but being electrically isolated therefrom, the electrode being positioned such that an arc will exist between the core and the electrode when a suitable electric potential is impressed across the core and the electrode, injection means for introducing a gaseous propellant into the hollow core such that the propellent flows through the arc, and radiation means surrounding the hollow core and being formed frOm a single material which is a different material than the material from which the core is formed, the radiation means being in intimate contact with the outwardly presented surface of the core for substantially the entire length of and entirely around the core so that heat from the arc will be conducted from the core to the radiation means, the radiation means being uncovered and exposed outwardly to open space so that it radiates the heat conducted through it away from the thrustor.

Claim 14

A thrustor according to claim 9 wherein the radiation means includes a flange which surrounds the core and has an outwardly opening cavity into which the hollow portion of the core opens.

Claim 15

A thrustor according to claim 9 wherein the radiation means and the core, aside from hollow central cavities therein, are substantially solid in cross section and are free of coolant channels so that heat conducts readily through them.