The Quantum Nature of Electrons
Haserodt, Kurt H.
MetadataShow full item record
Diffraction of individual electrons is considered in this automated experiment in an effort to demonstrate that single electrons exhibit a wave nature. A CRT with a polycrystalline target is used for diffraction and initial display of the pattern. An optical system is used to collect and focus the light from a precise area of the screen onto a photomultiplier tube (PMT) whose anode current is taken as a measure of light intensity. A current follower and integrator circuit are used to convert the photon induced current from the PMT into a voltage level, which is then converted to a digital value by an analog to digital converter. The digital number is read by a microcomputer and stored. A radial scanning method is used to take advantage of the circular symmetry of the diffraction pattern. The area of the screen that must be considered is thus greatly reduced. Such a scan requires that the optical equipment and the PMT must be moved linearly parallel to the CRT face. A description of how this is accomplished with a stepping motor and translation bed is given. The data collection and translation bed movement as well as the data manipulation and display are controlled by a microcomputer. A detailed description of the data conversion and control circuitry and the implementation techniques is given in an accompanying technical report. As the experiment remains unfinished, this paper concludes with a discussion of how the data to be obtained should be analyzed.