High sensitive 0.13 – 0.38 THz TES array radiometer for the big telescope azimuthal of Special Astrophysical Observatory of Russian Academy of Sciences

We are developing the high sensitive 0.13- 0.38 THz radiometer for 6 m optical telescope BTA of SAO RAS with the purpose to add frequency operation points in corresponding atmosphere transparency windows to already existing operation frequencies in observation facilities of the Observatory from ultraviolet region - 3000 Angstroms at BTA till maximum wavelength - 0.5 m of the radio telescope RATAN-600 of SAO RAS. This will give the possibility to carry out wide range multifrequency investigations in one observatory what does not have an analogue in the world. Main functional radiometer parts: high sensitive receiving elements, receiving antenna array, optical elements which matching telescope from focal plane till receiving antenna array, signal multiplexing circuit and 0.3 K cryogenic system - are described briefly.