Abstract: The problem about domestic electron cyclotron resonance neutralizer is that electron beam can′t be extracted continuously at the variation of bias voltage.To overcome this, an experiment of neutralizer electron beam extraction was carried out to improve the performance through changing the antenna structure and adjusting the size of the electron extraction aperture. The experimental results show that the electron beam can be extracted continuously with the increasing  of the bias voltage. The propellant efficiency and electron energy loss for the improved neutralizer under the operation conditions are 1.659 8 and 126.3 W/A respectively,while 1.278 9 and 194.573 W/A respectively before neutralizer improvement. The plasma density within the neutralizer diagnosed by the Langmuir probe is in the range of 1.72×10¹⁷~12.1×10¹⁷ m^-3.

Key words: electron cyclotron resonance(ECR), plasma, neutralizer, propellant efficiency, electron energy loss