Un cryostat fournit le banc optique de la plus grande caméra numérique astronomique (en anglais)

The Large Synoptic Survey Telescope (LSST) is currently under construction in Chile. The goal of this telescope is to conduct "a 10-year survey of the sky that will deliver a 200 petabyte set of images and data products that will address some of the most pressing questions about the structure and evolution of the universe and the objects in it"¹. The telescope site is in Chile.

It will be equipped with a special 8.4 meters mirror creating a wide field of view and a 3200 megapixel camera which must produce data of extremely high quality with minimal downtime and maintenance. In order to build this camera, the engineers and scientists at the Department of Energy's SLAC National Accelerator Laboratory at first completed a clean room in May 2015². A clean room is a facility designed to maintain extremely low levels of particles such as dust. Having a clean environment for the assembly of the camera was necessary to prevent dust settling on the image sensors, which would degrade the quality of the precision device.

On August 22, 2018, the Cryogenic Society of America published an article³ explaining that the optical bench of the camera is provided by a cryostat that keeps the large focal plane while cooling it to -101°C. It also provides cooling up to -34°C for the sensors' readout electronics. This cryostat has just been completed and delivered.

 

 

¹ LSST website. Available following this link.

² SLAC. Construction of LSST clean room at SLAC completed. In: SLAC website [online]. Available following this link.

³ Cryogenic Society of America. One cool camera: LSST’s cryostat assembly completed. In: Cryogenic Society of America website [online]. Available following this link.