Experimental Research on the Influence of Hollow Cathode to a Hall Thruster
|School||Harbin Institute of Technology|
|Course||Fluid Machinery and Engineering|
|Keywords||steady peculiarity diffuse hollow cathode Hall thruster performance|
As a electron source, hollow cathode is one of the critical components of Hall thruster (SPT). It can be used in two ways as follows: it supplies electron flux that is used for neutralize ion flux from channel of Hall thruster, and the plasma in plume is neutral. Furthermore, it provides electrons to ionize neutral gas in the channel. Parameters of hollow cathode selected have a great influence on the performance of Hall thruster.The paper show the structure and working principle of hollow cathode, study the influence of heating power (insert temperature) to the working parameters of hollow cathode. If heating power raises, the insert temperature and current density by hot emit will raise. If the cathode current is constant, electric field of insert and cathode voltage will decrease, thrust and efficiency of SPT will raise.The hollow cathode has many working modes. Diffuse emerge, when hollow cathode works in some parameters, and the reason of diffuse is not known. Due to diffuse, the cathode current changes largely, the stability of hollow cathode and SPT are affected. So the working range of SPT is limited. This paper researchs the influence of operating propellant flow rate, heating power, cathode current to the diffuse of hollow cathode, shows the regularity of starting point of diffuse mode affected. The result gives reference to the stable work range.The hollow cathode and SPT work coupled. Working position and parameters of hollow cathode have great influence to the performance of SPT. The paper study influence of axis positions, inclined distance, angle, operating propellant flow rate of cathode to the performance and plume symmetry of SPT. The result shows that axis positions of hollow cathode raise, the cathode coupling voltage decreases, the acceleration voltage of SPT raise, so the thrust and efficiency raise, the density of plasma and plume symmetry are constant. The inclined distance raise, the cathode coupling voltage decreases, the thrust and efficiency of SPT raise. The paper studys the change of cathode coupling voltage, when axis angle between cathode and thruster is 0 degree, 45 degree and 90 degree. When the axis angle between cathode and thruster is 45 degree, cathode coupling voltage is least, the performance of Hall thruster is best.