scholarly journals Divergent Plume Reduction of a High-Efficiency Multistage Plasma Thruster

2015 ◽  
Author(s):  
Christopher M Barlog
Keyword(s):  
High Efficiency ◽  
Plasma Thruster

scholarly journals Similarity scaling-application and limits for high-efficiency-multistage-plasma-thruster particle-in-cell modelling

2020 ◽  
Vol 60 (7) ◽  
pp. e201900199
Author(s):  
Paul Matthias ◽  
Daniel Kahnfeld ◽  
Stefan Kemnitz ◽  
Julia Duras ◽  
Norbert Koch ◽  
...  
Keyword(s):  
High Efficiency ◽  
Particle In Cell ◽  
Plasma Thruster ◽  
Similarity Scaling

Performance characterization of a high efficiency gas-fed pulsed plasma thruster

1997 ◽  
Author(s):  
J. Ziemer ◽  
E. Cubbin ◽  
E. Choueiri ◽  
Daniel Birx ◽  
J. Ziemer ◽  
...  
Keyword(s):  
High Efficiency ◽  
Pulsed Plasma ◽  
Performance Characterization ◽  
Pulsed Plasma Thruster ◽  
Plasma Thruster

Particle-in-cell simulation of an optimized high-efficiency multistage plasma thruster

2019 ◽  
Vol 59 (9) ◽  
pp. e201900028 ◽  
Author(s):  
Paul Matthias ◽  
Daniel Kahnfeld ◽  
Ralf Schneider ◽  
Suk Hyun Yeo ◽  
Hideaki Ogawa
Keyword(s):  
High Efficiency ◽  
Particle In Cell ◽  
Plasma Thruster ◽  
Cell Simulation

scholarly journals Review of Plasma-Induced Hall Thruster Erosion

2020 ◽  
Vol 10 (11) ◽  
pp. 3775 ◽  
Author(s):  
Nathan P. Brown ◽  
Mitchell L. R. Walker
Keyword(s):  
Computational Models ◽  
High Efficiency ◽  
Mitigation Strategies ◽  
Hall Thruster ◽  
The Past ◽  
Plasma Sputtering ◽  
Plasma Thruster ◽  
Material Physics ◽  
Erosion Mitigation ◽  
Experimental Findings

The Hall thruster is a high-efficiency spacecraft propulsion device that utilizes plasma to generate thrust. The most common variant of the Hall thruster is the stationary plasma thruster (SPT). Erosion of the SPT discharge chamber wall by plasma sputtering degrades thruster performance and ultimately ends thruster life. Many efforts over the past few decades have endeavored to understand wall erosion so that novel thrusters can be designed to operate for the thousands of hours required by many missions. However, due to the challenges presented by the plasma and material physics associated with erosion, a complete understanding has thus far eluded researchers. Sputtering rates are not well quantified, erosion features remain unexplained, and computational models are not yet predictive. This article reviews the physics of plasma-induced SPT erosion, highlights important experimental findings, provides an overview of modeling efforts, and discusses erosion mitigation strategies.

The High Efficiency Multistage Plasma Thruster HEMPT based Ion Propulsion System for the SmallGEO Satellite

2011 ◽  
Author(s):  
Norbert Koch ◽  
Stefan Weis ◽  
Martin Schirra ◽  
Alexey Lazurenko ◽  
Benjamin van Reijen ◽  
...  
Keyword(s):  
High Efficiency ◽  
Propulsion System ◽  
Plasma Thruster ◽  
Ion Propulsion

Microcalorimeters for X-Ray Spectroscopy

1988 ◽  
Vol 102 ◽  
pp. 41
Author(s):  
E. Silver ◽  
C. Hailey ◽  
S. Labov ◽  
N. Madden ◽  
D. Landis ◽  
...  
Keyword(s):  
High Resolution ◽  
High Efficiency ◽  
Thermal Response ◽  
Low Noise ◽  
High Resolution Spectroscopy ◽  
Superconducting Transition ◽  
Sapphire Substrates ◽  
Laboratory Plasmas ◽  
Adiabatic Demagnetization ◽  
Theoretical Predictions

The merits of microcalorimetry below 1°K for high resolution spectroscopy has become widely recognized on theoretical grounds. By combining the high efficiency, broadband spectral sensitivity of traditional photoelectric detectors with the high resolution capabilities characteristic of dispersive spectrometers, the microcalorimeter could potentially revolutionize spectroscopic measurements of astrophysical and laboratory plasmas. In actuality, however, the performance of prototype instruments has fallen short of theoretical predictions and practical detectors are still unavailable for use as laboratory and space-based instruments. These issues are currently being addressed by the new collaborative initiative between LLNL, LBL, U.C.I., U.C.B., and U.C.D.. Microcalorimeters of various types are being developed and tested at temperatures of 1.4, 0.3, and 0.1°K. These include monolithic devices made from NTD Germanium and composite configurations using sapphire substrates with temperature sensors fabricated from NTD Germanium, evaporative films of Germanium-Gold alloy, or material with superconducting transition edges. A new approache to low noise pulse counting electronics has been developed that allows the ultimate speed of the device to be determined solely by the detector thermal response and geometry. Our laboratory studies of the thermal and resistive properties of these and other candidate materials should enable us to characterize the pulse shape and subsequently predict the ultimate performance. We are building a compact adiabatic demagnetization refrigerator for conveniently reaching 0.1°K in the laboratory and for use in future satellite-borne missions. A description of this instrument together with results from our most recent experiments will be presented.

Imaging and diffraction modes in Scanning Transmission Electron Microscopy

1986 ◽  
Vol 44 ◽  
pp. 684-687
Author(s):  
J. M. Cowley ◽  
R. Glaisher ◽  
J. A. Lin ◽  
H.-J. Ou
Keyword(s):  
Scanning Transmission Electron Microscopy ◽  
High Efficiency ◽  
Fiber Optic ◽  
Image Intensifier ◽  
Detector System ◽  
Detector Plane ◽  
Secondary Electrons ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Special Detector

Some of the most important applications of STEM depend on the variety of imaging and diffraction made possible by the versatility of the detector system and the serial nature, of the image acquisition. A special detector system, previously described, has been added to our STEM instrument to allow us to take full advantage of this versatility. In this, the diffraction pattern in the detector plane may be formed on either of two phosphor screens, one with P47 (very fast) phosphor and the other with P20 (high efficiency) phosphor. The light from the phosphor is conveyed through a fiber-optic rod to an image intensifier and TV system and may be photographed, recorded on videotape, or stored digitally on a frame store. The P47 screen has a hole through it to allow electrons to enter a Gatan EELS spectrometer. Recently a modified SEM detector has been added so that high resolution (10Å) imaging with secondary electrons may be used in conjunction with other modes.

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