Operation of a Microwave Electron Cyclotron Resonance Cathode

The operation of a high-current electron cyclotron resonance (ECR) cathode was demonstrated at 2.45 GHz, and four variations in the baseline design configuration were evaluated. Reducing the ECR cathode extraction slot opening increased the internal chamber pressure and resulted in increased electron extraction current magnitude. Increasing the magnetic field near the antenna caused improvements in ionization efficiency. Extraction currents up to 2.35 A were attained for a xenon flow rate of 3.5 sccm at 125 W of microwave input power. Based on these findings, a new ECR neutralizer with a modified magnetic circuit accommodating 5.8 GHz operation will be fabricated and tested to demonstrate a significantly higher current capability.

[1]  M. Patterson,et al.  Microwave ECR Ion Thruster Development Activities at NASA GRC , 2002 .

[2]  H. Kuninaka,et al.  Overdense Plasma Production in a Low-power Microwave Discharge Electron Source , 2001 .

[3]  Michael J. Patterson,et al.  Outer Planet Exploration with Advanced Radioisotope Electric Propulsion , 2002 .

[4]  S. Satori,et al.  Development and Demonstration of a Cathodeless Electron Cyclotron Resonance Ion Thruster , 1998 .

[5]  J. Ishikawa,et al.  Development of microwave plasma cathode for ion sources , 1990 .

[6]  Michael J. Patterson,et al.  Space Station Cathode Design, Performance, and Operating Specifications , 1998 .

[7]  John R. Brophy,et al.  Status of the Extended Life Test of the Deep Space 1 Flight Spare Ion Engine After 30,000 Hours of Operation , 2003 .

[8]  J. Polk,et al.  An overview of the Nuclear Electric Xenon Ion System (NEXIS) program , 2003 .

[9]  George J. Williams,et al.  High Specific Impulse, High Power Ion Engine Operation , 2002 .

[10]  James S. Sovey,et al.  An ion propulsion system for NASA's Deep Space missions , 1999 .

[11]  John R. Anderson,et al.  Performance of the NSTAR ion propulsion system on the Deep Space One mission , 2001 .

[12]  James E. Polk,et al.  In-flight performance of the NSTAR ion propulsion system on the Deep Space One mission , 2000, 2000 IEEE Aerospace Conference. Proceedings (Cat. No.00TH8484).

[13]  Hitoshi Kuninaka,et al.  Result of 18,000-hour endurance test on microwave discharge ion thruster engineering model , 2000 .

[14]  S. Oleson,et al.  Electric Propulsion for Project Prometheus , 2003 .

[15]  M. Patterson,et al.  Discharge Characterization of 40 cm-Microwave ECR Ion Source and Neutralizer , 2003 .