Particle orbits near a neutral point

We study particle trajectories at an X-type neutral point, in the presence of a time-varying electric field. We present consequent distributions of electrons and protons, and suggest that a disturbance propagating through a neutral point may damp by particle acceleration.     

Instrument Boom Mechanisms on the THEMIS Satellites; Magnetometer, Radial Wire, and Axial Booms

The five “Time History of Events and Macroscale Interactions during Substorms” (THEMIS) micro-satellites launched on a common carrier by a Delta II, 7925 heavy, on February 17, 2007. This is the fifth launch in the NASA MeDIum class EXplorer (MIDEX) program. In the mission proposal the decision was made to have the University of California Berkeley Space Sciences Laboratory (UCB-SSL) mechanical engineering staff provide all of the spacecraft appendages, in order to meet the short development schedule, and to insure compatibility. This paper describes the systems engineering, design, development, testing, and on-orbit deployment of these boom systems that include: the 1 and 2 meter carbon fiber composite magnetometer booms, the 40 and 50 m tip to tip orthogonal spin-plane wire boom pairs, and the 6.3 m dipole stiff axial booms.