Concept of SUb-atmospheric Radio-frequency Engine (SURE) for near space environment

Abstract

A concept of SUb-atmospheric Radio-frequency Engine (SURE) designed for near space environment is reported. The antenna wrapping quartz tube consists of two solenoid coils with variable separation distance, and is driven by radio-frequency power supply (13.56 MHz-1 kW). The discharge involves inductive coupling under each solenoid coil and capacitive coupling between them. This novel scheme can ionize the filling air efficiently for the entire pressure range of 32 ∼ 5332 Pa in near space. The formed plasma density and temperature are up to 2.23 × 10 18 m −3 and 2.79 eV, respectively. The influences of separation distance, input power, filling pressure and the number of solenoid turns on discharge are presented in detail. This air-breathing electric propulsion system has no plasma-facing electrode and does not require external magnetic field, and is thereby durable and structurally compact and light.