SCT

Schwarzschild-Couder Telescope

»The SCT features a two-mirror optical system designed to cancel aberrations and de-magnify the images, so as to be compatible with a compact, high-resolution camera. «

The Schwarzschild-Couder Telescope (SCT), a dual mirror version of the Medium-Sized Telescope (MST), is proposed as a high-performance alternative to the MST. In collaboration with the SST-2M and MST groups on common components, institutes in the United States have been the pioneers of the SCT design since 2006. The SCT features a two-mirror optical system designed to cancel aberrations and de-magnify the images, so as to be compatible with a compact, high-resolution camera. The design achieves substantially better angular resolution over a wider field of view than classical single-mirror Cherenkov telescopes.

 

The SCTs have improved angular resolution as a result of a smaller point spread function (PSF) and the very large number of camera pixels (>11000), based on silicon photomultipliers (SiPMs), covering 8 degree field of view. Both the 9.7 m diameter primary and 5.4 m secondary mirrors are segmented and have active alignment. The SCT uses the same positioner as the MST and the camera technology developed for the SCT is also used in the SST-2M GCT. The main parameters of the SCT are in the below table.

 

Above, the SCT mechanical design. The positioning system is nearly identical to the MST. The unique optical support structure is designed to support segmented primary and secondary mirrors as well as the high angular resolution camera. It is designed to provide minimal shadowing, control of stray light and protection from sunlight during daytime parking.

SCT Camera

The SCT camera is composed of the mechanical enclosure, SiPMs mounted in focal plane modules, front-end electronics with preamps and first level trigger, and backplane electronics that provide the pattern trigger and data acquisition hardware. Data from nine subfield backplanes will be merged and delivered to the SCT Camera Server using standard high-speed communication protocols. Trigger and time synchronization signals from the backplanes will be relayed by the distributed array trigger electronics.

SCT Prototype

A SCT prototype is currently under construction at the Whipple Observatory south of Tucson, Arizona. The main goals of the prototype will be to demonstrate the performance of the optical system and gain experience with the optical alignment and operation of the SiPM camera. Watch the construction live:

SCT Contacts

SCT Coordinator: Vladimir Vassiliev

SCT Camera Coordinators:  Nepomuk Otte, Justin Vandenbroucke