Observation of very fast response signals from Pb absorber coupled transition edge sensor gamma-ray microcalorimeter

We are developing a gamma-ray microcalorimeter for Positron Annihilation Spectroscopy. Our detector composed of a transition edge sensor (TES) thermometer and an epoxy coupled bulk Pb absorber has been reported an energy resolution of 4.7 keV FWHM at 662 keV with a tens of milliseconds long response time. To enhance the detector properties, we designed a new attachment method in the focus of improving the thermal coupling between the absorber and the TES. In the new design, we created epoxy-posts both on the TES film and on the absorber, and then they were connected together using an epoxy-dot put on the epoxy-post on the absorber. Measured current signal of this epoxy-post TES gamma-ray detector showed an ultra fast response with 80 μs fall time.