ISSN:
1089-7550
Source:
AIP Digital Archive
Topics:
Physics
Notes:
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 β. 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 βtp is an odd multiple of π, where tp 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 βtp is an even multiple of π. 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.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.349577
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