MONOLITHIC SILICON BOLOMETERS COUPLED TO WAVEGUIDE

We have measured the performance of ion-implanted silicon bolometers developed for observations of faint astrophysical sources at millimeter wavelengths. These devices are mounted in waveguide to couple to a single mode of electromagnetic radiation. We measure optical coupling efficiencies of ~ 90 % across a full waveguide band. When cooled to 0.1 K and operated under low background conditions, the devices have a time constant of 1.5 – 4 ms and NEP ~ . They have a small cross-section to cosmic rays. We describe an application of these bolometers to a balloon-borne measurement of the 2.7 K cosmic microwave background radiation at frequencies between 65 and 170 GHz