Author: National Aeronaut Administration (Nasa)
Publisher: Createspace Independent Publishing Platform
ISBN: 9781722693176
Category :
Languages : en
Pages : 74
Book Description
A report describing the operating principles of hollow-cathode-based plasma contactors emitting or collecting electrons from an ambient plasma is summarized. Preliminary experiments conducted to determine the noise generated by these plasma contactors in the emission-current return line and in the plasma near it are described. These noise data are measured as current fluctuations in the return line and to the Langmuir probe and then analyzed using a fast Fourier transform technique. The spectral compositions of the data are characterized using power spectral density plots which are examined to identify possible noise source(s) and production mechanism(s). The precautions taken in the construction and calibration of the instrumentation to assure adequate frequency response are described. Experimental results show that line-current noise levels are typically 2 percent of the electron current being emitted or collected. However, noise levels increase to as much as 20 percent of the electron current at a few electron-collection operating conditions. The frequencies associated with most of the noise were harmonics of the 60 Hz input to system power supplies. Plasma noise had characteristics similar in magnitude and frequency to those for the return-line noise, but they contained additional features at frequencies considered to be related to ion-acoustic instabilities. Also discussed is a new probe positioning system built to facilitate future plasma-contractor research. Buchholtz, Brett and Williams, John D. and Wilbur, Paul J. Unspecified Center...
Plasma Contactor Research - 1991
Author: National Aeronaut Administration (Nasa)
Publisher: Createspace Independent Publishing Platform
ISBN: 9781722693176
Category :
Languages : en
Pages : 74
Book Description
A report describing the operating principles of hollow-cathode-based plasma contactors emitting or collecting electrons from an ambient plasma is summarized. Preliminary experiments conducted to determine the noise generated by these plasma contactors in the emission-current return line and in the plasma near it are described. These noise data are measured as current fluctuations in the return line and to the Langmuir probe and then analyzed using a fast Fourier transform technique. The spectral compositions of the data are characterized using power spectral density plots which are examined to identify possible noise source(s) and production mechanism(s). The precautions taken in the construction and calibration of the instrumentation to assure adequate frequency response are described. Experimental results show that line-current noise levels are typically 2 percent of the electron current being emitted or collected. However, noise levels increase to as much as 20 percent of the electron current at a few electron-collection operating conditions. The frequencies associated with most of the noise were harmonics of the 60 Hz input to system power supplies. Plasma noise had characteristics similar in magnitude and frequency to those for the return-line noise, but they contained additional features at frequencies considered to be related to ion-acoustic instabilities. Also discussed is a new probe positioning system built to facilitate future plasma-contractor research. Buchholtz, Brett and Williams, John D. and Wilbur, Paul J. Unspecified Center...
Publisher: Createspace Independent Publishing Platform
ISBN: 9781722693176
Category :
Languages : en
Pages : 74
Book Description
A report describing the operating principles of hollow-cathode-based plasma contactors emitting or collecting electrons from an ambient plasma is summarized. Preliminary experiments conducted to determine the noise generated by these plasma contactors in the emission-current return line and in the plasma near it are described. These noise data are measured as current fluctuations in the return line and to the Langmuir probe and then analyzed using a fast Fourier transform technique. The spectral compositions of the data are characterized using power spectral density plots which are examined to identify possible noise source(s) and production mechanism(s). The precautions taken in the construction and calibration of the instrumentation to assure adequate frequency response are described. Experimental results show that line-current noise levels are typically 2 percent of the electron current being emitted or collected. However, noise levels increase to as much as 20 percent of the electron current at a few electron-collection operating conditions. The frequencies associated with most of the noise were harmonics of the 60 Hz input to system power supplies. Plasma noise had characteristics similar in magnitude and frequency to those for the return-line noise, but they contained additional features at frequencies considered to be related to ion-acoustic instabilities. Also discussed is a new probe positioning system built to facilitate future plasma-contractor research. Buchholtz, Brett and Williams, John D. and Wilbur, Paul J. Unspecified Center...
Plasma Contactor Research - 1991
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 74
Book Description
Publisher:
ISBN:
Category :
Languages : en
Pages : 74
Book Description
An Investigation of Conducted and Radiated Emissions from a Hollow-cathode Plasma Contactor
Author: Brett W. Buchholtz
Publisher:
ISBN:
Category : Electric contactors
Languages : en
Pages : 104
Book Description
Publisher:
ISBN:
Category : Electric contactors
Languages : en
Pages : 104
Book Description
Advanced Electric Propulsion Research, 1991
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 82
Book Description
Publisher:
ISBN:
Category :
Languages : en
Pages : 82
Book Description
Scientific and Technical Aerospace Reports
Author:
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 464
Book Description
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 464
Book Description
Plasma Contactor Research, 1989
Author: National Aeronaut Administration (Nasa)
Publisher: Createspace Independent Publishing Platform
ISBN: 9781722693220
Category :
Languages : en
Pages : 80
Book Description
The characteristics of double layers observed by researchers investigating magnetospheric phenomena are contrasted to those observed in plasma contacting experiments. Experiments in the electron collection mode of the plasma contacting process were performed and the results confirm a simple model of this process for current levels ranging to 3 A. Experimental results were also obtained in a study of the process of electron emission from a hollow cathode plasma contactor. High energy ions are observed coming from the cathode in addition to the electrons and a phenomenological model that suggests a mechanism by which this could occur is presented. Experimental results showing the effects of the design parameters of the ambient plasma simulator on the plasma potential, electron temperature, electron density and plasma noise levels induced in plasma contacting experiments are presented. A preferred simulator design is selected on the basis of these results. Williams, John D. Unspecified Center...
Publisher: Createspace Independent Publishing Platform
ISBN: 9781722693220
Category :
Languages : en
Pages : 80
Book Description
The characteristics of double layers observed by researchers investigating magnetospheric phenomena are contrasted to those observed in plasma contacting experiments. Experiments in the electron collection mode of the plasma contacting process were performed and the results confirm a simple model of this process for current levels ranging to 3 A. Experimental results were also obtained in a study of the process of electron emission from a hollow cathode plasma contactor. High energy ions are observed coming from the cathode in addition to the electrons and a phenomenological model that suggests a mechanism by which this could occur is presented. Experimental results showing the effects of the design parameters of the ambient plasma simulator on the plasma potential, electron temperature, electron density and plasma noise levels induced in plasma contacting experiments are presented. A preferred simulator design is selected on the basis of these results. Williams, John D. Unspecified Center...
Monthly Catalog of United States Government Publications
Author:
Publisher:
ISBN:
Category : Government publications
Languages : en
Pages :
Book Description
Publisher:
ISBN:
Category : Government publications
Languages : en
Pages :
Book Description
Monthly Catalogue, United States Public Documents
Author:
Publisher:
ISBN:
Category : Government publications
Languages : en
Pages : 1702
Book Description
Publisher:
ISBN:
Category : Government publications
Languages : en
Pages : 1702
Book Description
A Numerical, Parametric Study of Plasma Contactor Performance
Author: John Joseph Blandino
Publisher:
ISBN:
Category :
Languages : en
Pages : 252
Book Description
Publisher:
ISBN:
Category :
Languages : en
Pages : 252
Book Description
Space Plasma Contactor Research, 1987
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 94
Book Description
Publisher:
ISBN:
Category :
Languages : en
Pages : 94
Book Description