Simulation of a TES Structure Using a Radiation Absorber Self-adjusting the Operation Temperature.

We have developed a dynamic simulation method to analyze TES dynamics. This simulation code is based on heat diffusion and Maxwell’s equations. With this simulation, we can calculate transition temperatures and can map current flow in the devices. We can also reproduce signal waveforms. We apply this method to our new TESs. Our new structures are a combination of a TES (e.g., Ir) and a serially connected radiation absorber (e.g., Au). In this design, Joule heating in the TES and radiation absorber stabilizes the absorber temperature through a negative feedback process. What is more, with this new design scheme, we can tune TES parameters such as residual resistivity ratio (RRR), transition width, and normal electrical resistance. As a trial, we have fabricated two iridium TESs with 150um×150um×390nm gold absorbers mounted on a common silicon nitride membrane. Sizes of the TESs are 25um×25um×100nm, and 25um×50um×100nm respectively. They are parallel voltage biased to one readout circuit. The simulation shows that signals from each TES of the twin-TES structure have specific shapes and can be easily distinguished. [ABSTRACT FROM AUTHOR]