Background-limited membrane-isolated TES bolometers for far-IR/submillimeter direct-detection spectroscopy

• Published in: Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment Accelerators, spectrometers, detectors and associated equipment, 2006-04, Vol.559 (2), p.456-458
• Main Authors: Kenyon, M., Day, P.K., Bradford, C.M., Bock, J.J., Leduc, H.G.
• Format: Article
• Language: English
• Subjects: [formula omitted] thermal transport; Far-IR spectrometer; Submillimeter spectrometer; Transition-edge sensor
• ISSN: 0168-9002; 1872-9576
• DOI: 10.1016/j.nima.2005.12.036

We fabricated and measured the thermal conductance of suspended Si 3 N 4 beams via noise thermometry to determine whether membrane-isolation bolometers are capable of reaching a phonon noise equivalent power (NEP) of 4 × 10 - 20 W / Hz 1 / 2 . This sensitivity is necessary for the Background-Limited Infrared-Submillimeter Spectrograph (BLISS) proposed for the Japanese SPICA observatory, and adequate for NASA's SAFIR observatory, a 10-m, 4 K telescope to be deployed at L2. The dimensions of the longest thermal isolation beams we measured are 3 × 0.5 × 8300 μ m 3 . We also fabricated and measured the electrical properties of superconducting molybdenum/gold transition-edge sensor (TES) bolometers with isolation beams of an identical geometry. The thermal conductance ( G) values obtained from the noise thermometry and the TES bolometer data when the transition temperature ( T c ) of the thermistor is 60 mK correspond to an NEP of 5 × 10 - 20 W / Hz 1 / 2 , making membrane-isolated TES bolometers a strong candidate for use on BLISS-SPICA and SAFIR.