"What you can do is reflect the light travelling away from the cloud back into the camera lens," said Cheong. As they were bouncing ideas around, staff scientist Joe Frisch came up with the idea of mirrors. The solution popped up, Schwartzman said, during a brainstorming session in the lab.
Atom picture windows#
This could gather more of the reemitted light, but it would require more windows or, alternatively, fitting the cameras inside the chamber, and there isn’t much space in there for a bunch of cameras. One idea is to use a wide aperture, or opening, to let more light into the camera, but there's a tradeoff: A wide aperture creates what photographers call a narrow depth of field, where only a narrow slice of the picture is in focus.Īnother possibility would be to position more cameras around a cloud of strontium atoms. "You're only going to collect as much light as falls on the lens,” said Safdari, “which is not a lot." Mirrors to the rescue If it's not intense enough, light from the clouds will be too dim for the cameras to see. However, if the laser light is too intense, it can destroy the details scientists want to see. To illuminate the strontium clouds, experimenters will shine lasers on the clouds. The camera itself must sit outside a chamber and peer through a window across a relatively long distance to see the strontium clouds within.īut the real problem is light.
The strontium clouds themselves are small, only about a millimeter across, and the details that researchers need to see are about a tenth of a millimeter across. To see the interference patterns, researchers will literally take pictures of a cloud of strontium atoms, which comes with a number of challenges. This interference pattern is sensitive to anything that changes the relative distance between the pairs of quantum waves or the internal properties of the atoms, which might be influenced by the presence of dark matter. When re-combined, the waves create an interference pattern in strontium atom wave, similar to the complex pattern of ripples that emerges after skipping a rock on a pond. Each strontium atom acts like a wave, and the laser light sends each of these atomic waves into a superposition of quantum states, one of which continues on its original path while the other one is kicked much higher up. Known as an atom interferometer, it will exploit quantum phenomena to detect passing waves of ultralight dark matter and free-falling strontium atoms.Įxperimenters will release clouds of strontium atoms in a vacuum tube that runs the length of the shaft, and then shine laser light on the free-falling clouds.
The 100-meter-long Matter-wave Atomic Gradiometer Interferometric Sensor, or MAGIS-100, is a new kind of experiment being installed in a vertical shaft at DOE's Fermi National Accelerator Laboratory. "We're advancing the imaging in experiments like MAGIS-100 to the newest imaging paradigm with this system," Safdari said. As a result, the mirror system can help researchers build a three-dimensional model of an object, such as an atom cloud. Because the camera now gathers views of an object taken from many different angles, the system is an example of “light-field imaging”, which captures not just the intensity of light but also which direction light rays travel. By arranging mirrors in a dome-like configuration around an object, they can reflect more light towards the camera and image multiple sides of an object simultaneously.Īnd, the team reports in the Journal of Instrumentation, there's an additional benefit. Researchers at the Department of Energy's SLAC National Accelerator Laboratory realized that task would be perhaps the ultimate exercise in ultra-low light photography.īut a SLAC team that included Stanford graduate students Sanha Cheong and Murtaza Safdari, SLAC Professor Ariel Schwartzman, and SLAC scientists Michael Kagan, Sean Gasiorowski, Maxime Vandegar, and Joseph Frish found a simple way to do it: mirrors.
Atom picture how to#
But first, researchers need to figure out something pretty basic: how to get good photographs of the clouds of atoms at the heart of their experiment. When it goes online, the MAGIS-100 experiment at the Department of Energy's Fermi National Accelerator Laboratory and its successors will explore the nature of gravitational waves and search for certain kinds of wavelike dark matter.