DESI

It took three sky surveys to prepare for a new project that will create the largest 3-D map of the universe’s galaxies and glean new insights about the universe’s accelerating expansion. This Dark Energy Spectroscopic Instrument project will explore this expansion, driven by a mysterious property known as dark energy, in great detail. The surveys, which wrapped up in March, have amassed images of more than 1 billion galaxies and are essential in selecting celestial objects to target with DESI, now under construction in Arizona.

The optical lenses for the Dark Energy Spectroscopic Instrument have seen their first light. Fermilab contributed key components to DESI, including the corrector barrel and its support structures, along with vital software that ensures the instrument’s 5,000 robotic positioners are precisely aligned with their celestial targets.

From Berkeley Lab, Dec. 4, 2018: Key components of Berkeley Lab’s Dark Energy Spectroscopic Instrument are installed after months of planning, prep work. A team at Fermilab built the corrector, hexapod, and other top-end support structures. The structures are designed to align the lenses with an accuracy of tens of microns (millionths of a meter) – similar to the width of the thinnest human hair.

The building boom

These international projects, selected during the process to plan the future of U.S. particle physics, are all set to come online within the next 10 years.

From Berkeley Lab, Aug. 9, 2016: DESI, the Dark Energy Spectroscopic Instrument, will measure light from 35 million galaxies to provide new clues about dark energy. Fermilab is a collaborator on the Berkeley Lab project.