The Arcminute Microkelvin Imager
\mnras 391 (2008) 1545-1558
Dielectric constant reduction using porous substrates in finline millimetre and submillimetre detectors
Proceedings of SPIE - The International Society for Optical Engineering 7020 (2008)
Abstract:
Finlines are planar structures which allow broadband and low loss transition from waveguide to planar circuits. Their planar structure and large substrate makes them ideal for integration with other planar circuits and components, allowing the development of an on chip Polarimeter. We have developed a method of extending the employment of finlines to thick substrates with high dielectric constants by drilling or etching small holes into the substrate, lowering the effective dielectric constant. We present the results of scale model measurements at 15GHz and cryogenic measurements at 90GHz which illustrate the excellent performance of finline transitions with porous substrates and the suitability of this technique for extending the bandwidth of finline transitions.Performance of microstrip-coupled TES bolometers with finline transitions
Proceedings of SPIE - The International Society for Optical Engineering 7020 (2008)
Abstract:
We have fabricated TES bolometers with finline transitions for the C lOVER project. We have measured the optical response of C lOVER's first prototype 97-GHz detectors and find that they have a detection efficiency close to 100%. We have also investigated the effects of misalignment of the finline in the waveguide and of thinning the substrate. The prototype detectors have dark NEPs as low as 1.5 × 10-17WZv-Hz and satisfy the requirement of photon-noise limited operation on C lOVER. We describe the optical tests of ClOVER's prototype 97-GHz detectors and discuss their implications for the design of the science-grade detectors.The Cℓ over experiment
Proceedings of SPIE - The International Society for Optical Engineering 7020 (2008)
Abstract:
CℓOVER is a multi-frequency experiment optimised to measure the Cosmic Microwave Background (CMB) polarization, in particular the B-mode component. CℓOVER comprises two instruments observing respectively at 97 GHz and 150/225 GHz. The focal plane of both instruments consists of an array of corrugated feed-horns coupled to TES detectors cooled at 100 mK. The primary science goal of CℓOVER is to be sensitive to gravitational waves down to r ∼ 0.03 (at 3σ) in two years of operations.Waveguide-to-planar circuit transition for millimetre-wave detectors
ArXiv 0806.0255 (2008)