  An efficient numerical code FP3D has been developed to calculate particle
orbits and evaluate particle confinement in 3D magnetic fields including
stellarators and tokamaks with 3D fields. The magnetic field is either
calculated from coils directly or obtained from equilibrium codes. FP3D has
been verified with the 3D equilibrium code VMEC (S. P. Hirshman, Phys. Fluids
26, 3553 (1983)) for magnetic field calculation and with the drift-kinetic code
SFINCS (M. Landreman, Physics of Plasmas 21 (4) (2014)) for neoclassical
transport. The code has been applied successfully to the NCSX stellarator (B.
Nelson, Fusion Engineering and design 66 (2003)) for the calculation of
neoclassical transport coefficient with the 3D magnetic field obtained directly
from coils. FP3D is also used to calculate ripple losses in the tokamak EAST
(W. Yuanxi, Plasma Science Technology 8 (3) (2006)).
