This is a still frame from an artist's animated rendering of the MAGIS Device (magnetically activated and guided isotope separation).
To begin the MAGIS process, unpurified ore is vaporized and enters an optical pumping region where a one-watt laser (red beam) tuned to a specific wavelength magnetizes only the particles of the desired isotope so that they are repelled by a magnetic field. The magnetized and unmagnetized particles enter a curved tunnel lined with permanent magnets, called a wave guide. The particles must follow the curve to make it to the collector at the end, but can only do so if repelled by the magnetic field. Since only the particles of one isotope are magnetized (blue dots), only those particles make the trip and end up in the collector.
The MAGIS method was developed by Mark Raizen, Tom Mazur and Bruce Klappauf. The full animation can be viewed at https://www.youtube.com/watch?v=zIRi-7AxFAM.