Evaluation of 256-pixel TES microcalorimeter arrays with electrodeposited Bi absorbers

Abstract: We succeeded in fabricating 256-pixel arrays of Ti/Au transition edge sensor (TES) microcalorimeters with electrodeposited microabsorbers made of Bi, and report on their test results. We confirmed all pixels tested so far were alive, however most of the microabsorbers were stripped off during cooling cycles. We investigated some pixels by irradiating with 5.9keV X-rays, and confirmed that they actually worked as microcalorimeters. The X-ray pulses are represented by a sum of two components with different decay times. The ratio of the two components fluctuates from pulse to pulse, which limits the energy resolution to . We discuss the pulse shape of two decay-time components considering thermal conductivities, i.e., inside microabsorbers, between microabsorbers and TES. [Copyright &y& Elsevier]