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Title: Rail electrodynamics in a plasma armature railgun

Journal Article · · Journal of Applied Physics; (USA)
DOI:https://doi.org/10.1063/1.349577· OSTI ID:5651013
; ; ;  [1]
  1. Science Applications International Corporation, 1247-B North Eglin Parkway, Shalimar, Florida 32579 (US)

A model is developed to investigate rail electrodynamics in a plasma armature railgun. This model describes the rail motion in response to the transitory Lorentz force and the compressive restoration force from the material which is between the rails and the containment structure. In this model the distance between the rails is found to oscillate with a frequency of {beta}. The magnetic field and the dynamic behavior of the rails induce local electric fields. We investigate the significance of these electric fields in the laboratory frame and in the projectile frame. In the lab frame, rail electrodynamics induces local electric fields which have maximums spaced behind the projectile at locations where {beta}{ital t}{sub {ital p}} is an odd multiple of {pi}, where {ital t}{sub {ital p}} is the time since the projectile has passed an axial location on the rails. When the projectile is accelerating, rail dynamics induce electric fields in the projectile frame which have maximums where {beta}{ital t}{sub {ital p}} is an even multiple of {pi}. As the projectile velocity increases, the locations of the peak voltages move farther behind the projectile. For the CHECMATE railgun, calculations indicate that the rail displacement is on the order of 2 mm, the rail velocity is on the order of 50 m/s, and the voltages induced in the projectile frame are on the order of 20--40 V.

OSTI ID:
5651013
Journal Information:
Journal of Applied Physics; (USA), Vol. 70:3; ISSN 0021-8979
Country of Publication:
United States
Language:
English