Titanium-based optical transition edge sensors under the ion irradiation

Transition edge sensors (TES) are highly sensitive detectors and have been widely used at different wavelengths from millimeter to X-ray astronomy. Especially at optical/near infrared wavelengths TES exhibits photon-number resolving capability because of its high energy resolution, which also makes it attractive in quantum information. In order to verify the possibility of space applications, we study the effect of ion irradiation on the performance of titanium-based optical TESs including normal-state resistance (RN), critical temperature (TC), thermal conductance (G), effective response time, detection efficiency, and energy resolution by measuring the DC and optical characteristics. The optical TESs survive in the ion irradiation and their parameters keep almost the same as before ion irradiation, which makes it possible for future space applications.