ELECTROSTATIC DEFOCUSING OF ONE-ELECTRON WAVE-PACKETS

We perform numerical simulation of defocusing of a one-electron wave p acket scattered by a de electric field of a negatively charged spheric al electrode. An electron packet accelerated by a potential difference propagated toward the center of a metal sphere with a sufficiently hi gh negative potential. At a certain distance from the surface of the s phere, the packet stopped and then began to move in the opposite direc tion. The motion of the packet in the backward direction was accompani ed by a drastic increase in the transverse sizes of the packet. In the vicinity of the stop point, the longitudinal size of the packet steep ly decreased by more than three orders of magnitude, then sharply incr eased up to its initial size, and remained virtually constant later on . At a distance of 50 cm from the sphere, the transverse sizes of the packet reached 1 cm, and the longitudinal size was about 40 mu m. An e xperimental observation of such a macroscopic wave packet is discussed .