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

TL;DR

This paper introduces the SURE concept, a novel radio-frequency engine for near space that efficiently ionizes air without electrodes or magnetic fields, enabling durable and lightweight electric propulsion.

Contribution

It presents a new RF-driven plasma generation scheme for near space, eliminating electrodes and magnetic fields, with detailed analysis of operational parameters.

Findings

Achieved plasma density up to 2.23×10^{18} m^{-3}

Demonstrated efficient ionization across 32 to 5332 Pa pressure range

Developed a durable, electrode-free propulsion system

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\sim 5332 Pa in near space. The formed plasma density and temperature are up to 2.23\times 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.