Maxwell coils are solenoids of spheroidal shape which produce a constant magnetic field inside the coil; at large distances the field of a Maxwell coil becomes that of a magnetic dipole. The current in systems consisting of several confocal Maxwell coils can be adjusted in such a way that the magnetic field inside the smallest coil is constant and the back flux is confined to the interior of the largest coil. Quantum-mechanical scattering of charged particles by Maxwell coils, or systems thereof, is first formulated as a three-dimensional problem and then treated within a two-dimensional approximation. The evolution in time of wave packets, which are Gaussian wave packets in the beginning, is calculated numerically. In all cases an Aharonov-Bohm effect is observed in the angular distribution of the scattered wave packets. The back flux results only in an additional deflection of the packets, which corresponds to the classical deflection caused by the Lorentz force.
Neutron-multiwave-interference phenomena based on Ramsey's resonance method of ``separated oscillating fields'' are studied. A neutron passes through N successive resonant coils $(\ensuremath{\Elzxh}{\ensuremath{\omega}}_{0}=2{\ensuremath{\mu}}_{n}{B}_{0}),$ which flip the neutron spin with a probability $\ensuremath{\rho}$ smaller than 1. These coils are separated by path lengths L over which a homogeneous field
B1 is present. Because the spin-flip probability $\ensuremath{\rho}$ is smaller than 1, the number of waves for a neutron is doubled after each flipper, so as to produce
2N neutron waves at the end of the setup. The phase difference between any pair of waves is a multiple of a ``phase quantum'' determined by the line integral of the field difference ${B}_{1}\ensuremath{-}{B}_{0}$ over the length L. Highly regular patterns of the quantum-mechanical probability R in ${(B}_{1},\ensuremath{\rho})$ space appear due to pair interference between individual waves. Possible applications of this phenomenon, such as a direct measurement of n-particle correlation function, are pointed out.