TERAHERTZ RECEIVER WITH NbN HEB DEVICE (TREND) - A LOW-NOISE RECEIVER USER INSTRUMENT FOR AST/RO AT THE SOUTH POLE

Based on the excellent performance of NbN HEB mixer receivers at THz frequencies which we have established in the laboratory, we are building a Terahertz REceiver with NbN HEB Device (TREND) to be installed on the 1.7 meter diameter AST/RO submillimeter wave telescope at the Amundsen/Scott South Pole Station. TREND is scheduled for deployment during the austral summer season of 2002/2003. The frequency range of 1.25 THz to 1.5 THz was chosen in order to match the good windows for atmospheric transmission and interstellar spectral lines of special interest. The South Pole Station is the best available site for THz observations due to the very cold and dry atmosphere over this site. In this paper, we report on the design of this receiver. In particular, we report measured beam patterns and polarization sensitivity at THz frequencies for a log-periodic antenna/lens combination, accurate measurements of the frequencies of two laser lines which are suitable for two of the spectral lines of greatest interest (NII and CO), as well as the mixer block design and other aspects of the design of the receiver system.