Publications (2)1.37 Total impact
Article: Electrical and optical measurements on the first SCUBA-2 prototype 1280 pixel submillimeter superconducting bolometer array[show abstract] [hide abstract]
ABSTRACT: SCUBA-2 is a submillimeter camera being built for the James Clerk Maxwell Telescope in Hawaii. Bringing CCD style imaging to the submillimeter for the first time, with over 10 000 pixels, it will provide a revolutionary improvement in sensitivity and mapping speed. We present results of the first tests on a prototype 1280 pixel SCUBA-2 subarray; the full instrument will be made up of eight such subarrays. The array is made up of transition edge sensor (TES) detectors, with Mo/Cu bilayers as the sensing element. To keep the number of wires reasonable, a multiplexed readout is used. Unlike previous TES arrays, an in-focal plane multiplexer configuration is used, in which the multiplexing elements are located beneath each pixel. To achieve the required performance, the detectors are operated at a temperature of approximately 120 mK. We describe the results of a basic electrical and optical characterization of the array, demonstrating that it is fully operational. Noise measurements were made on several pixels and gave a noise equivalent power below 2.5×10−17 W HZ−0.5, within the requirements for SCUBA-2. The construction of the testbed used to carry out these measurements is also described.Review of Scientific Instruments 02/2007; 78(2):024502-024502-7. · 1.37 Impact Factor
Article: Characterization of a prototype SCUBA-2 1280 pixel submillimetre superconducting bolometer array[show abstract] [hide abstract]
ABSTRACT: We present the results of characterization measurements on a 1280 pixel superconducting bolometer array designed for operation at wavelengths around 450 µm. The array is a prototype for the sub-arrays which will form the focal plane for the SCUBA-2 sub-mm camera, being built for the James Clerk Maxwell Telescope (JCMT) in Hawaii. With over 10 000 pixels in total, it will provide a huge improvement in both sensitivity and mapping speed over existing instruments. The array consists of molybdenum-copper bi-layer TES (transition edge sensor) pixels, bonded to a multiplexer. The detectors operate at a temperature of approximately 175 mK, and require a heat sink at a temperature of approximately 60 mK. In contrast to previous TES arrays, the multiplexing elements are located beneath each pixel (an "in-focal plane" configuration). We present the results of electrical and optical measurements, and show that the optical NEP (noise equivalent power) is less than 1.4 × 10 −16 W Hz −0.5 , and thus within the requirement of 2.9 × 10 −16 W Hz −0.5 .Proc SPIE 01/2006; 6275.