This is an illustration of a NIST chip that makes polarized xenon gas. Xenon atoms (green) are loaded into the chamber on the left. The xenon flows into the next chamber, where the atoms are polarized through collisions with rubidium atoms (red) that are illuminated with circularly polarized light. Then the xenon flows into the smaller chamber, where its polarization is measured, using the rubidium atoms in the same chamber as magnetometers. Atoms exit the chip from the chamber on the far right.