Electrical Characteristics of Superconducting Ti Transition Edge Sensors.

We have designed and fabricated superconducting Ti transition edge sensors (TES) with different microbridge lengths varying from 1 to 6 $$\upmu $$ m. The current-voltage characteristics of the fabricated Ti TESs are measured at different bath temperatures using a commercial SQUID amplifier. The thermal conductance ( G) is found to be about 300 pW/K for a 2.6- $$\upmu $$ m-long device. In addition, the effective response time measured with a current pulse signal is about 3 $$\upmu $$ s, and decreases with increasing the bias voltage because of negative electro-thermal feedback. The obtained electrical noise equivalent power from the measured current noise is about $$4 \times 10^{-17}$$ W/Hz $$^{0.5}$$ , which is sufficiently low for TeSIA instrument. [ABSTRACT FROM AUTHOR]