This study presents the Langmuir and Faraday probe measurements conducted to determine the plume characteristics of the BUSTLab microwave electrothermal thruster(MET).The thruster,designed to operate at 2.45 GHz frequ...This study presents the Langmuir and Faraday probe measurements conducted to determine the plume characteristics of the BUSTLab microwave electrothermal thruster(MET).The thruster,designed to operate at 2.45 GHz frequency,is run with helium,argon and nitrogen gases as the propellant.For the measurements,the propellant volume flow rate and the delivered microwave power levels are varied.Experiments with nitrogen gas revealed certain operation regimes where a very luminous plume is observed.With the use of in-house-built Langmuir probes and a Faraday probe with guard ring,thruster plume electron temperature,plasma density and ion current density values are measured,and the results are presented.The measurements show that MET thruster plume effects on spacecraft will likely be similar to those of the arcjet plume.It is observed that the measured plume ion flux levels are very low for the high volume flow rates used for the operation of this thruster.展开更多
The microwave absorption efficiency, which is relevant to magnet field and its distribution, is a major parameter of the microwave ion source (MWIS) for the intense neutron tube. Based on previous work, the relations ...The microwave absorption efficiency, which is relevant to magnet field and its distribution, is a major parameter of the microwave ion source (MWIS) for the intense neutron tube. Based on previous work, the relations between microwave absorption efficiency and plasma chamber structure and thickness of the microwave introduction window are studied. The microwave absorption efficiency reaches to 100% when plasma chamber is 100mm long and the window thickness is 30mm. The microwave absorption efficiency as a function of pressure is also presented.展开更多
文摘This study presents the Langmuir and Faraday probe measurements conducted to determine the plume characteristics of the BUSTLab microwave electrothermal thruster(MET).The thruster,designed to operate at 2.45 GHz frequency,is run with helium,argon and nitrogen gases as the propellant.For the measurements,the propellant volume flow rate and the delivered microwave power levels are varied.Experiments with nitrogen gas revealed certain operation regimes where a very luminous plume is observed.With the use of in-house-built Langmuir probes and a Faraday probe with guard ring,thruster plume electron temperature,plasma density and ion current density values are measured,and the results are presented.The measurements show that MET thruster plume effects on spacecraft will likely be similar to those of the arcjet plume.It is observed that the measured plume ion flux levels are very low for the high volume flow rates used for the operation of this thruster.
基金Innovation Fund for Technology-based Small Firms (99C26212210085)
文摘The microwave absorption efficiency, which is relevant to magnet field and its distribution, is a major parameter of the microwave ion source (MWIS) for the intense neutron tube. Based on previous work, the relations between microwave absorption efficiency and plasma chamber structure and thickness of the microwave introduction window are studied. The microwave absorption efficiency reaches to 100% when plasma chamber is 100mm long and the window thickness is 30mm. The microwave absorption efficiency as a function of pressure is also presented.
