‘World’s Largest Camera’ Secures Key DOE Approval

The U.S. Department of Energy has granted intermediate approval for construction of a 3.2-gigapixel CCD camera to be integrated into the Large Synoptic Survey Telescope (LSST).

Components of the 3-ton camera will be built by an international collaboration led by the SLAC National Accelerator Laboratory, where the camera will be assembled and tested.

The Department of Energy has endorsed the organization’s request for $168 million. Another review process will begin next summer, the last requirement before fabrication of the camera can begin.

A 3.2-gigapixel camera for the Large Synoptic Survey Telescope will be the largest ever built. Courtesy of the SLAC National Accelerator Laboratory.

The proposed camera contains a focal plane array comprised of 189 4K × 4K CCD sensors with 10 micron pixels. The sensors are deep-depletion, back-illuminated devices with a highly segmented architecture that enables the entire array to be read out in 2 s.

The detectors are grouped in identical 3 × 3 arrays called rafts. Each raft includes dedicated front-end and back-end electronics boards. The rafts and associated electronics are mounted on a silicon carbide grid inside a cryostat.

The entrance window to the cryostat is the third of three refractive lenses. The other two lenses are mounted in the front of the camera body. The camera body also contains a mechanical shutter and an exchange system for five large optical filters. A sixth optical filter will also be fabricated and can replace any of the five filters during a daytime access.

Preliminary, privately funded work has already started on the telescope’s 8.4-m primary mirror, its 3.5-m secondary mirror, and the initial excavation of its site atop Cerro Pachon, a mountain in northern Chile. The National Science Foundation has pledged up to $473 million for the telescope project.

The LSST is set to begin taking digital images of the entire visible southern sky in 2022. Over a 10-year period, it will detect tens of billions of objects and will produce movies based on 6 million GB of details captured per year.

It will help researchers study the formation of galaxies, track potentially hazardous asteroids, observe exploding stars and better understand dark matter and dark energy.

For more information, visit www.lsst.org.