Susceptibility Study of TES Micro‑calorimeters for X‑ray Spectroscopy Under FDM Readout

We present a characterization of the sensitivity of TES X-ray micro-calorimeters to environmental conditions under frequency-domain multiplexing (FDM) readout. In the FDM scheme, each TES in a readout chain is in series with a LC band-pass filter and AC biased with an independent carrier at MHz range. Using TES arrays, cold readout circuitry and...

Small Size Transition-Edge Sensors for Future X-Ray Applications

Large arrays of transition edge sensors (TESs) are the baseline for a number of future space observatories. For instance, the X-ray integral field unit (X-IFU) instrument on board the ATHENA space telescope will consist of ∼ 3000 TESs with high energy resolution (2eV at X-ray energies up to 7 keV). In this contribution we report on the...

Lateral Inverse Proximity Effect in Ti/Au Transition Edge Sensors

We report measured T_c of superconducting Ti/Au bilayer strips with a width W varying from 5 to 50 µm. The strips were fabricated based on a Ti/Au bilayer that consists of a 41-nm-thick Ti layer to which a 280-nm-thick Au layer was added. We find that the T_c drops as W decreases and the declining trend almost perfectly...

Single Pixel Performance of a 32 x 32 Ti/Au TES Array With Broadband X-Ray Spectra

We are developing a kilo-pixels Ti/Au TES array as a backup option for Athena X-IFU. Here we report on single-pixel performance of a 32 × 32 array operated in a Frequency Division Multiplexing (FDM) readout system, with bias frequencies in the range 1-5 MHz. We have tested the pixels response at several photon energies, by means of a 55Fe...

The SPICA-SAFARI TES Bolometer Readout: Developments Towards a Flight System

SAFARI is an imaging Fourier Transform Spectrometer for 35–200 ?m under development for flight on the Japanese IR-satellite SPICA (2018). The 3.25 m diameter actively cooled telescope (<6K) will provide a sky background limited signal, which implies that detectors will need to have an NEP of 3.5?10 ?19 W/Hz ? ? ? in order not to be limiting the...