Optical design of the large sub-millimeter Atacama telescope, LSAT

The study of the evolution of the early universe, when the first galaxies began to form, is one of the driving factors in the development of large infrared and sub-millimeter telescopes. The large sub-millimeter Atacama telescope (LSAT) is the result of a collaborative effort between Cornell University and the California Institute of Technology (Caltech) to develop a conceptual design of a 25-meter class sub-mm telescope that will operate primarily in the far-infrared/sub-millimeter (FIR/sub-mm) spectral regime, from 350 GHz up to 1.5 THz (λ>200 μm), at a high, dry site in the Atacama region of northern Chile, at an altitude of more than 5,000 meters. LSAT, with larger field of view and large format focal plane arrays, will have mapping speeds up to 2,500 times those of ALMA (Atacama large millimeter array), 2 arc-sec resolution at shortest wavelengths, point-source sensitivities at least 20 times better than any planned sub-mm facility and confusion 10 times lower than any existing single-aperture telescope. The paper discusses the telescope´s reflector optics.