  We study, both classically and quantum-mechanically, the problem of a neutral
particle with spin S, mass m and magnetic moment mue, moving in two-dimensions
in an inhomogeneous magnetic field given by B_x=B'*x; B_y=-B'*y; B_z=B;
  We identify K, the ratio between the precessional frequency of the particle
and its vibration frequency, as the relevant parameter of the problem.
  Classicaly, we find that when the magnetic moment is antiparallel to B, the
particle is trapped provided that K<sqrt{4/27}. We also find that viscous
friction, be it translational or precessional, destabilizes the system.
  Quantum-mechanically, we study the problem of spin S=h_bar/2 particle in the
same field. Treating K as a small parameter for the perturbation from the
adiabatic Hamiltonian, we find that the lifetime T_esc of the particle in its
trapped ground-state is T_esc={T_vib}/{128 pi^2} * exp{2/K} where T_vib is the
classical period of the particle when placed in the adiabatic potential V=mue
*|B(x,y)|
