In the classical double-slit experiment, where light or particles are used, the interference pattern that emerges on the screen behind the slits is a result of the wave nature of the particles. However, if we were to use two parallel electron guns perpendicular to the slits in a classical setup, or introduce multiple guns and multiple slits, the resulting pattern would be different from the typical interference pattern.
When using two parallel electron guns, each gun would emit a stream of electrons, creating two separate beams. If these beams pass through the double slits, they would act independently of each other. Each beam would diffract and spread out, resulting in two separate distributions of electrons on the screen behind the slits. There would be no interference between the two beams, and the resulting pattern would consist of two separate distributions corresponding to each beam.
Similarly, if we were to introduce multiple guns and multiple slits, each gun would emit its own beam of electrons, and each beam would independently diffract through the corresponding slits. The resulting pattern on the screen would then be a combination of the individual distributions created by each beam. There would be no interference between the different beams, and the pattern would consist of multiple separate distributions corresponding to each beam.
In both cases, the absence of interference between the beams is due to the classical nature of the setup and the particles involved. In the classical domain, particles do not exhibit wave-like behavior or interference patterns, as described by quantum mechanics. Instead, they behave more like individual particles, and their distributions are determined by their trajectories and the initial conditions of the system.
It's important to note that in the context of the classical double-slit experiment, electrons would typically exhibit particle-like behavior, and their wave nature would not be evident in the absence of quantum effects. The wave-like behavior of electrons is typically observed in the quantum realm, where phenomena such as wave-particle duality and interference patterns arise.