Heater/emitter assembly

A heater/emitter for a rocket engine assembly utilizes a resistance heated wire coil or coils which may also function as a cathode emitter or as a thermal driver for an auxiliary emitter. This heater/emitter may if desired be formed into a bifilar and may be supported by the wire lead itself or by isolated supports. The power leads are located in a lead channel and feature an overwrapping of similar wire material which reduces the internal resistance heating of the lead to increase the electrical conductivity of the supporting lead and increase the thermal conduction thereof to establish a cooler and structurally-stronger lead. A plurality of radiation discs or shields are spaced along the leads to further minimize energy losses from the heater out of the lead channel. The heater/emitter itself is enclosed, except for the lead channel, by a heat exchanger housing. The function of this housing is to accept energy from the hot heater coil and in turn transfer that energy to a fluid flowing through the heat exchanger. Power is transferred from the hot heater coil to the heat exchanger firstly by means of radiation heat transfer, and secondly by impingement of thermionic electrons accelerated thru a potential imposed between the emitter and the heat exchanger. This packaging approach permits radiation transfer efficiencies, from coil to heat exchanger, of 90 to 95 percent. The thermionic electron emission and acceleration efficiency approaches 100 percent. The dual energy transfer mode permits single device operation over wider power ranges and thrust levels than would be permitted by single mode devices. The device may be operated in the single mode as a radiation transfer heater or as a combination radiator and emitter, or may function with the principal energy transfer being in the emitter mode only.