2.1 Version 4.6

1. When using load_particles to load simulation particles from a file, in the past the particles had to enter through one of the three planes z = z_min, z = z_max, or r = r_max. If a metal boundary existed just inside the plane, particles would simply be eliminated. It is now possible for particles to enter through the metal boundary on the left-hand side of the simulation region. This feature was added following a request from J. Edelen (FNAL).
2. The beam snapshot (from define_snapshots) now includes a status column that indicates whether particles are active.