Comparative study of PTFE filled different dopants as propellants for laser-electric hybrid thruster

摘要

This study presents a broad comparison of samples, which are made of polytetrafluoroethylene (PTFE) filled with different dopants according to the same preparation steps, as propellants on a laser-electric hybrid thruster with a common design base. The impulse bit, specific impulse, efficiency and discharge success rate of the propellant samples were measured and analyzed under the same operation. The experimental results illustrated that the dopants of alloy could improve the impulse bit, that of salt could promote the stability of the discharge process, and the samples doped with oxide performed dramatic specific impulse and thrust efficiency. And three representative samples were adopted to investigate the dependence of propulsion characteristics on different working parameters in the respective doping ratios. It is found that the sample doped with TiO2 in lower doping rate was expected to rank maximal specific impulse and efficiency at most operations, especially under the conditions of low laser energy, long discharge width and high initial voltage. And the samples doped with Co-Cr alloy in low doping ratio appeared better performance at low discharge width and laser energy, while those in high doping ratio performed greater performance at high discharge width and laser energy.