David H. McIntyre
Dept. of Physics, Oregon State University
SPINS is an interactive computer
program that simulates Stern-Gerlach measurements on spin-1/2 and
spin-1 particles. The original Macintosh version was written by D. V.
Schroeder (see Am. J. Phys.
61, 798 (1993)). We have
developed a JAVA version for use in the
Paradigms course PH425: Spin and Quantum Measurement (see
Activities utilizing the SPINS program are described in our
Quantum Mechanics text and on our activity website.
This page contains an enhanced version of SPINS developed by Wolfgang Christian and Mario Belloni of the Open Source Physics
Note the bug discussed below.
The SPINS OSP program is available as an applet or an application:
APPLET: Click the button below to run the SPINS OSP Applet within a browser.
APPLICATION: The SPINS OSP application is available in two versions: a standalone version or a curricular package with embedded exercises desigend by the OSP team (different from the OSU exercises). In either case, the program is packaged as a jar file. Download it to your machine with the links below (you may have to right click and save).
If you have Java installed on your computer, you can double click on the jar file, or from the directory where the file resides type the following command to run the Java code:
>java -jar qm_spins.jar (for standalone version)
>java -jar osp_spins.jar (for curricular package)
If you do not have Java, you can download the Java
Runtime Engine from Sun
(JRE). Read this HELP file to see how to use the OSP SPINS curricular package.
Help for the SPINS program is available in
pdf format. This same help file is available in the program by selecting the Help menu item.
There is a software bug in the spin-1 case when combining 2 beams from one analyzer (combining 3 beams works). This bug manifests itself in SPINS Lab 3. The system seems to "lose" some atoms. The final counts are too low, though the relative probabilities are correct, which is why the bug was not found sooner. The bug has been fixed in the previous version listed below, but not yet in the OSP version.