Comparative study of component erosion for electromagnetic and electrothermal launchers

Bourham, Mohamed; Hankins, O.E.; Gilligan, J.G.; Hurley, J.D.; Earnhart, J.

doi:10.1109/20.195736

Cited by 11 publications

(2 citation statements)

References 13 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…If that were the case and if the depth of the erosion Seen in these tests were averaged over the brush portion of the electrode, then the erosion rate would be about 4-6 mg per coulomb. Low erosion of non-thoriated tungsten electrodes has been noted by other authors [5,6,7]. We found thoriated tungsten to be a low erosion material for electrodes and expect it is better than non-thoriated tungsten.…”

Section: B Plasma Brush Formationmentioning

confidence: 54%

Materials evaluation for use as plasma brush electrodes with hybrid armatures

1995

View full text Add to dashboard Cite

AWucf-There is a strong motivation to develop a railgun armature which will function as a non-arc, solid contact armature throughout the complete projectile acceleration to launch process. Solid contact armatures are more ef'ficient in converting electrical to kinetic energy and generally cause less erosion of the rail. Considerable effort is being directed towards designing armatures capable of reaching 3+km/s while avoiding transition from a solid to an arcing contact. While nearly 2 W s has been achieved in a non-arcing contact, it may be inevitable that an arcing contact will be unavoidable during the finial acceleration to full desired velocities. At present most solid armatures are fabricated from aluminum or copper. While aluminum or copper might be good choices for solid contacts, this paper introduces the possibility that a different material will better serve as an electrode in an arcing contact. For example upon transition, the'conduction of current through a plasma brush results in rapid erosion of aluminum armatures. When transition to an arcing contact occurs, we have found that magnetic pressure can be used to minimize the length of the plasma brush, which helps minimize the mass of the armature and improves the overall effiiency of energy transfer to the projectile payload. However, Short length brushes result in high current density, and high erosion rates. We have measured the erosion of aluminum surfaces when used as a cathode and as an anode while magnetically containing the brushes. We have also measured the erosion of a thoriated tungsten (W-Th) cathode when used in the same manner. The erosion of the W-Th was more about a factor of 100 less than the A.! This paper presents these results and a discussion of electron emission for AI, Cu, W and W-Th.

show abstract

Section: B Plasma Brush Formationmentioning

confidence: 54%

Materials evaluation for use as plasma brush electrodes with hybrid armatures

1995

View full text Add to dashboard Cite

show abstract

“…In terms of heat flux measurement, Bourham et al established a plasma source, SIRENS, to investigate the ablation damage on different materials [9,10] and film coating technology [11], where thermocouples were used to measure the heat flux. By means of an infrared (IR) camera, Williams et al measured the temperature of a copper disk and propellant grains exposed to a hydrocarbon ablation-supported plasma [12] with an approximate average heat flux of 40 MW m −2 .…”

Section: Introductionmentioning

confidence: 99%

Effects of wire materials on radiative heat flux and spectral characteristics of a capillary discharge plasma jet

Yang¹,

Fan²,

Chen³

et al. 2019

J. Phys. D: Appl. Phys.

View full text Add to dashboard Cite

Capillary discharge plasmas have been widely used in many fields. This paper investigates the influence of different explosion wire materials on the radiative heat flux and spectral characteristics. Three kinds of wire (aluminum, copper and nickel) with 0.3 mm diameter were used as initiation wires to produce an electrothermal plasma, with a capacitor charging voltage of 3 kV. A thin-film calorimeter with high response speed was used for the measurement of the radiative heat flux. At the same time, spectral analysis was performed using a spatially resolved spectrometer with an ICCD. Based on the results, the electrical energy transported to the plasma that is calculated from the voltage and current traces follows the order Cu > Al > Ni, while the radiative heat flux follows the order Al > Cu > Ni. The trends can be explained by the secondary combustion (chemical reaction with the air) of Al and the fact that the dissipated energy is smaller than the vaporization energy for Ni but larger for Al and Cu, resulting in a bad performance in jet heat flux due to the incomplete vaporization of Ni wires. For the Cu and Al cases, a four-stage evolution process of the emitted radiation, which describes the emission, absorption and decay processes, can be found from the spectral analysis.

show abstract

Characterization of Short Intense Pulsed Electrothermal Plasma Capillaries for Use as Fusion and Launchers Heat Flux Sources

Al-Halim

Bourham

2014

J Fusion Energ

View full text Add to dashboard Cite

Comparative study of component erosion for electromagnetic and electrothermal launchers

Cited by 11 publications

References 13 publications

Materials evaluation for use as plasma brush electrodes with hybrid armatures

Materials evaluation for use as plasma brush electrodes with hybrid armatures

Effects of wire materials on radiative heat flux and spectral characteristics of a capillary discharge plasma jet

Characterization of Short Intense Pulsed Electrothermal Plasma Capillaries for Use as Fusion and Launchers Heat Flux Sources

Contact Info

Product

Resources

About