The program orst.spins.Spins is an interactive computer program that simulates Stern-Gerlach-type measurements on spin-1/2 and spin-1 particles. The original Java Version was written by David McIntyre and was based on the original Macintosh version by Dan Schroeder [Am. J. Phys. 61, 798 (1993)]. Within the context of the OSP project, the Java program has been extended allowing for "experimental" parameters to be saved in XML files. Once an experiment is set up using the toolbar, the exact configuration can be saved and then reloaded. This allows for specialized initial states and more complicated arrangements of analyzers to be easily created.
These examples depict the measurement of a beam of spin-1/2 particles. When an analyzer is blue, it can be clicked and its orientation changed. When an analyzer is black, its orientation is fixed. In addition, spin-1 particles and particles that obey SU(3) can be configured in the initial beam. The initial states can be a statistical mixture, an eigenstate of a given spin operator or a superposition of eigenstates.
The Default Configuration shows the SPINS program with the default parameters. The Custom Configuration shows an experiment where the oven produces a particular, pre-programmed, superposition of spin-1 eigenstates. The Custom Interface shows the SPINS program with an example of a which-way experiment with an interferometer (here the menu bar is not shown and only the relevant control buttons are displayed). The user can toggle between a "watching" and a not watching mode by clicking the purple button.