NIST F2 Clock Animation Description for the Visually Impaired

Animation Description for the Visually Impaired | News Release | Backgrounder | Animation on YouTube

Text on screen: NIST-F2 Atomic Clock

Visual: A computer-animated model of the clock, which appears as a long silver-colored tube.

Text on screen: Sequences shown in slow motion and changes exaggerated for clarity.

Visual: The clock becomes transparent and the pieces are labeled. The vacuum chamber is at the very base. An array of infrared laser point into the vacuum chamber. Above that is a microwave cavity ring and a photon detector. On top, a liquid nitrogen dewer surrounds a hollow tube.

Text on screen: Gas of cesium atoms introduced into vacuum chamber.

Visual: The camera zooms in on the vacuum chamber. Many small, colored spheres representing cesium atoms move randomly around inside the chamber. The array of lasers activates and pushes the cesium atoms into a ball.

Text on screen: Lasers cool and push atoms into a ball.

Visual: Another laser activates and the ball of cesium atoms move upward.

Text on screen: Lasers push atom ball upward.

Visual: The atoms pass through the microwave emitter where they are energized.

Text on screen: Microwaves interact with atoms.

Visual: The ball of atoms moves up into the refrigerated chamber. As the atoms descend they pass through the microwave chamber and are energized by a probe laser.

Text on screen: Microwaves interact with atoms.

Visual: The atoms emit some light, which hits a sensor.

Text on screen: Some atoms change energy levels and emit light.

Visual: The camera pans to a computer screen that plots how much light the atoms have emitted on a graph. The first group of atoms has not emitted much light. A laser lofts another ball of atoms upwards through the microwave emitter ring and into the cooled chamber.

Text on screen: Microwaves at higher frequency, closer to atomic resonance.

Visual: The ball of atoms is lofted up through the microwave emitter ring and into the cooled chamber above. As the atoms descend they pass through the microwave chamber and are energized by a probe laser. The atoms emit light. The camera pans to a computer screen that plots how much light the atoms have emitted on a graph. The second group of atoms has emitted much more light.

Visual: Another ball of atoms is lofted up through the microwave emitter ring and into the cooled chamber above.

Text on screen: Microwave frequency too high – off resonance.

Visual: As the atoms descend they pass through the microwave chamber again and energized by a probe laser.

Text on screen: Fewer atoms change energy levels and emit light.

Visual: The atoms emit light. The camera again pans to a computer screen that plots how much light the atoms have emitted on a graph. The third group of atoms has emitted less light than the second. Camera centers on computer screen graph. Each peak, labeled F1, F2, and F3 is displayed. The F2 peak is taller than the others.

Text on screen: Maximum signal at microwave frequency of 9,192,631,770 Hertz

Visual: Arrow from text points to taller F2 peak.

Text on screen: This is used to define the international unit of time – the second.

Screen fades to black.