ST-40 HALL TRUSTER TESTING WITH LaB6 HOLLOW CATHODE

Abstract


 
 
 The results of experimental investigation of the ST-40 Hall thruster operating with a heating hexaboride cathode are presented. The readiness of the heating hollow cathode to the thruster start was assessed by reducing the cathode keeper voltage from the start value of 100 V to 15 ... 17 V, when an internal discharge in the hollow cathode occurred. Various cyclograms of the thruster start are considered with the definition of the purpose of the cyclogram, which ensures reliable thruster start. Three cyclograms of the thruster start are investigated: with the thruster’s electromagnet coils switched on; with the coils off; without switching off the voltage at the hollow cathode keeper, which made it possible to restart the thruster without preheating the hollow cathode. The obtained cyclograms make it possible to ensure a reliable start of the ST-40 thruster when operating with a heating hexaboride hollow cathode. In the course of laboratory research, the PPU-300 power processing unit was used. It ensured the stabilization of the discharge power in the thruster’s accelerating channel and stabilization of the currents supplied to the central and external coils of the thruster. The main operating characteristics and parameters of the ST-40 thruster were obtained for three fixed values of the discharge power: 265, 281, 300 W and a change in the mass flow rate of the working substance (Xenon) through the anode unit of the thruster 0.7 ... 1.3 mg/sec. Experimental investigation of the ST-40 thruster in a wide range of parameters made it possible to determine the optimal thruster’s parameters that provide the maximum values of thrust and specific impulse for the given values of the discharge power in the accelerating channel of the thruster and the minimum discharge current. The process of the thruster’s parameters optimizing was carried out by changing the currents flowing through the internal and external coils of the thruster. In the course of experimental research, it was found that the inner coil and the serially connected outer coils can be connected in parallel and powered by a single power supply. Experimental studies have confirmed the correctness of the adopted technical solutions in the development of the ST-40 Hall thruster and the heating hexaboride hollow cathode.
 
 

Detection of the magnetic field parameters influence on discharge current fluctuations and optimal operation modes of the hall thruster

“…As an object of research, the fluctuations of the discharge current of the modernized ST-40M Hall thruster were considered, which differs from the previously designed ST-40 model [12] in that the structure of the insulators was changed in it, as well as a new cathode with heater was used. An emitting insert made of LaB 6 material was applied in the cathode.…”

“…The purpose of this work is to increase the efficiency of the ST-40M thruster by optimizing the parameters of the magnetic field in the accelerating channel. This will make it possible to determine the optimal operating modes of the ST-40M thruster, which provide the greatest values of traction, specific impulse, and overall efficiency [12,13].…”

Parameters of the St-40m Hall Thruster With Increased Power Discharge Supply

“…1. The use of a new cathode for modified ST-40M thruster made it possible to significantly facilitate the process of the thruster starting and ensure its operation at a higher level of discharge input power [5,6]. The problem statement of this research was to experimentally determine the algorithm for the thruster starting; determine the main parameters of the thruster: thrust, specific impulse and anode efficiency; as well as the main characteristics of the thruster at a discharge input power of 300 -550 W at a change of the anode mass flow rate of the working substance (Xe) and the value of a discharge voltage.…”

Power Processing and Control Unit of the Eectric Propulsion System

“…Let's consider the SPS-40 electric propulsion system, which includes two ST-40 Hall thruster, a working substance storage and feeding system (XFS) and a power processing and control unit (PPU), the block diagram of which is shown in Fig. 1 [1,2]. In frame of the propulsion system two Hall thrusters are used, each of which contains two hollow cathodes.…”