Proximity effects in Transition Edge Sensors (TESs) do shape the
superconducting transition and are potentially responsible for
non-ideal behavior and undesired non-uniformity in multiplexed large
arrays of X-ray microcalorimeters for the XIFU instrument on board of
the future ESA space mission Athena.
In particular, nonlinear effects in the resistance and the reactance
when the TES detector are ac biased at MHz frequency, like it is the
case for the Frequency Division Multiplexing read-out under development
The TES physics can be fairly well described by the Josephson effect
using the Resistively Shunted Junction (RSJ) model.
Previous experiments on TES based micro-calorimeters and bolometers,
and the related theoretical work, suggested that the resistive
transition could be calculated from the analytical solution of the
Langevin equation for the Brownian motion of a particle in a tilted
potential, as described in Coffey et al. , once the TES fundamental
parameters like the TES normal resistance Rn and the TES critical
current Ic(T) as a function of temperature have been experimentally
In this paper, we use the above mentioned theoretical framework to
simulate the R(T,I,f_bias) transition surface for the latest generation of
devices currently under developed for XIFU.
|Less than 5 years of experience since completion of Ph.D||N|
|Student (Ph.D., M.Sc. or B.Sc.)||N|