Microscopic observation of operating Ir/Au-TES microcalorimeter by low-temperature scanning synchrotron microscopy

To investigate the variation of the signal response caused by the complicated intermediate state of the superconducting transition edge, a low temperature scanning synchrotron microscopy (LTSSM) technique was applied to the microscopic observation of the signal response of an Ir/Au-TES as a function of bias condition. The TES was irradiated with 6 keV X-rays collimated with a 20-μmφ pinhole. Two-dimensional X-ray signal response maps show a variation of about 5–6 eV depending on the bias voltage. Bank regions show a clearly smaller amplitudes.