Abstract:
We present measurements of the thermal conductance, G, and effective time constants,\u03C4 of three transition-edge sensors (TESs) populated in arrays operated from 80-87mK with TC~120mK. Our TES arrays include several variations of thermal architecture enabling determination of the architecture that demonstrates the minimum noise equivalent power (NEP), the lowest \u03C4 and the trade-offs among designs. The three TESs we report here have identical Mo/Cu bilayer thermistors and wiring structures, while the thermal architectures are: 1) a TES with straight support beams of 1mm length, 2) a TES with meander support beams of total length 2mm and with 2 phononfilter blocks per beam, and 3) a TES with meander support beams of total length 2mm and with 6 phonon-filter blocks per beam. Our wiring scheme aims to lower the thermistor normal state resistance RN and increase the sharpness of the transition =dlogR/dlogT at the transition temperature TC. We find an upper limit of given by (25+10), and G values of 200fW/K for 1), 15fW/K for 2), and 10fW/K for 3). The value of can be improved by slightly increasing the length of our thermistors. PACS numbers: 85.25.Pb; 95.85.-e; 85.25.-j