Performance of titanium optics on a NASA 30 cm ion thruster

Soulas, George C.; Foster, John E.; Patterson, Michael J.

doi:10.2514/6.2000-3814

Cited by 20 publications

(17 citation statements)

References 11 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…One potential solution to this problem is the use of a magnetic grid. 10 Potential design solutions also exist for increasing the lifetime of the ion optics by using different electrode materials such as titanium 11 or carbon [12][13] or by simply increasing the electrode thickness. 14 Failure mode 5 involves unclearable shorts between the grids.…”

Section: Design Considerationsmentioning

confidence: 99%

The High Power Electric Propulsion (HiPEP) Ion Thruster

Foster

Haag

Patterson

et al. 2004

40th AIAA/ASME/SAE/ASEE Joint Propulsion Conference and Exhibit

Self Cite

View full text Add to dashboard Cite

Section: Design Considerationsmentioning

confidence: 99%

The High Power Electric Propulsion (HiPEP) Ion Thruster

Foster

Haag

Patterson

et al. 2004

40th AIAA/ASME/SAE/ASEE Joint Propulsion Conference and Exhibit

Self Cite

View full text Add to dashboard Cite

“…11 Comparing the NEXT and NSTAR flatness parameters indicated that the NEXT EM1 ion engine beam flatness parameters were 45 to 85 percent higher than those of the NSTAR ion engine. 5,12 Higher flatness parameters apparently correspond directly with increased electron backstreaming limits, and are speculated to have contributed to increases in ion optics perveance and screen grid ion transparencies relative to those of the 30 cm ion optics on an NSTAR engine. The higher beam flatness parameters of the NEXT ion engine can also lead to reduced accelerator aperture enlargement near the grid center.…”

Section: A Near-field Radial Beam Current Density Profilesmentioning

confidence: 99%

Single-String Integration Test Measurements of the NEXT Ion Engine Plume

Snyder

Kamhawi

Patterson³

et al. 2004

40th AIAA/ASME/SAE/ASEE Joint Propulsion Conference and Exhibit

Self Cite

View full text Add to dashboard Cite

Measurements were made of a 40 cm ion-thruster plume as part of the single-string-integration-test (SSIT) activity of Phase I of the NASA's Evolutionary Xenon Thruster (NEXT) project. The NEXT ion engine incorporates design improvements that extend NSTAR power levels and efficiencies. During SSIT, an engineering model (EM2) 40 cm engine was operated using an advanced xenon propellant system in combination with either a GRC power console or advanced power processing unit. Integral goals of the single-string phase were to characterize engine performance over the full input power range and to detail thruster operation within the specification of the NEXT throttle table. Plume diagnostics measurements of relative Xe + and Xe ++ currents were made using near-field and far-field ExB probes. Planar geometry faraday probes were used to obtain beam current density profiles. This paper reports on the characterization of the EM2 plume over a range of SSIT operating conditions, first with the advanced propellant management system teamed with the GRC power console and then with the power-processing unit. I. IntroductionThe need for advanced ion propulsion system capabilities has been demonstrated through in-space propulsion technology assessment analyses conducted by NASA. A higher power, higher throughput capability 25 kW ion propulsion system targeted for robotic exploration of the outer planets was identified as an enabling technology. This power level is an order of magnitude greater than that used on the Deep-Space 1 spacecraft 1 developed and flown under the NASA Solar Electric Propulsion Technology Applications Readiness (NSTAR) program.The NASA Headquarters Office of Space Science, Solar System Exploration Division, selected Glenn Research Center (GRC) to develop NASA's Evolutionary Xenon Thruster (NEXT) under the Next Generation Ion (NGI) Thruster Technology NASA Research Announcement. The NEXT team is composed of NASA GRC, the Jet Propulsion Laboratory (JPL), Aerojet Redmond Rocket Center, and Boeing Electron Dynamic Devices (BEDD), with significant participation by the Applied Physics Laboratory, University of Michigan (UM) and Colorado State University (CSU).The Next Generation Electric Propulsion (NGEP) Project, managed by the NASA Marshall Space Flight Center, is a technology development project within the In-Space Propulsion Technology Program. The primary objective of NGI is to significantly increase performance for primary propulsion to planetary bodies by leveraging NASA's ion propulsion program for low thrust applications. The NEXT system is targeted for robotic exploration of the outer planets using 25kW-class solar-powered electric propulsion. The team will develop thruster, advanced power processing, xenon propellant management and gimbal technologies that will advance the ion propulsion state-of-art to meet the needs of such missions. 2 Component performance was demonstrated over a one-year duration of NEXT phase I, which was completed in August 2003. These components included engineering model...

show abstract

“…However, titanium's 1.8 × higher thermal expansion coefficient than molybdenum caused the grids to make contact during thruster startup, when differential heating of the grids is most severe. 4 During that test, the thruster was set to 2.3 kW (i.e. peak NSTAR thruster input power) within 1 minute following discharge ignition, and the screen grid came into contact with the accelerator grid within 5 minutes of ignition near the center of the beam extraction area.…”

Section: -5mentioning

confidence: 99%

“…Although this grid set had bonded together due to temperature differences between the grids during thruster startup on a prior test, the grids were subsequently separated, and aperture alignment and cold grid gap changes were found to be negligible. 4 For these tests, the cold grid gap at the ion optics center where the pin was mounted was measured to be 0.69 mm. Variations throughout the active area were within +0%/-4% of this dimension.…”

Section: B Ion Optics and Thrustermentioning

confidence: 99%

“…4, a thruster using titanium ion optics was started from room temperature and operated with beam extraction at full power within 1 minute of discharge ignition. The screen grid came into contact with the accelerator grid and, during one of the several recycles that resulted from this contact, enough energy was provided to this region of contact for the grids to bond together.…”

Section: B Possible Resolutions For Operation With Titanium Gridsmentioning

confidence: 99%

See 1 more Smart Citation