Dynamics of a Rotating Proton Layer along a Magnetic Ramp.
Abstract
The dynamics of a rotating proton layer containing 2 - 6 x 10 to the 16th power protons of 1 - 1.5 MeV energy propagating in vacuum along a ramp mangetic field have been studied experimentally and by computer simulation. The layer is produced by passing the annular proton pulse produced by an Inverse Reflex Tetrode (IRT) through a magnetic cusp. The diamagnetic self-magnetic field (as high as 1.6 times the applied field) and the radial oscillations of the layer are monitored. The axial velocity of the pulse is determined, and a maximum of 1.7 is obtained for the ratio of azimuthal to axial velocity. The layer has also been propagated along the ramp in the presence of a neutral gas cloud with pressure approximately greater than 0.1 Torr. Computer simulation of the experiment uses an axisymmetric particle-in-cell code that includes self- and external- Bz and Br magnetic fields and the inductive E theta electric field. Calculated contour maps of the particle and current densities of the beam at selected times are presented. The computer particle density profile, the ratio v theta/vz, and the magnitude of the diamagnetic signals are in qualitative agreement with the observations. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 31, 1981
- Accession Number
- ADA111349
Entities
People
- Chris A. Kapetanakos
- D. E. Pershing
- James R. Golden
- John Pasour
- S. J. Marsh
Organizations
- United States Naval Research Laboratory