Development of hard X-ray and gamma-ray spectrometer using superconducting transition edge sensor

Superconducting transition edge sensors (TES) are used for high-resolution X-ray spectroscopy. In our group, we developed an Ir-TES and reported an energy resolution of 6.9 eV FWHM at 5.9 keV (Kunieda et al., 2004). In this study, we have designed a new TES detector using a superconducting tin (Sn) absorber to detect high energy photons over 100 keV. The Sn absorber is coupled to an Ir/Au superconducting film which is deposited on an ultra-thin SiN membrane (500 nm thick) with a small amount of epoxy post (Stycast 2850FT) by handling with a flip-chip bonding machine. The measured energy resolution is 485 eV FWHM at 60 keV and is better than that of HPGe detector. ► We designed a Gamma-ray Spectrometer using superconducting transition edge sensor. ► Sn absorber was coupled to an Ir/Au superconducting film through the Stycast epoxy. ► An extremely small epoxy post was fabricated on a 500 nm thick SiN membrane. ► The absorber was coupled to a superconducting film using flip-chip bonding machine. ► We have achieved a better energy resolution than conventional HPGe detectors.