Energy calibration of superconducting transition edge sensors for x-ray detection using pulse analysis

Abstract

Transition edge sensors (TESs) have been developed to be used as high-resolution x-ray detectors. They show excellent energy resolution and can be used in many applications. TESs are a special kind of calorimeters that can determine small temperature changes after x-ray absorption. Such a temperature change causes a strong resistance change (superconducting to normal-conducting phase transition) that can be measured. The energy calibration of a TES based spectrometer is problematic due to the nonlinear behavior of the detector response. In this article, a method is introduced to calibrate the energy scale of TES spectra. This is accomplished by calculating the energy dependence of the response of the detector operated in electrothermal feedback mode. Using this method a calibration accuracy of a few eV for an x-ray energy of 6keV can be achieved. Examples of energy dispersive x-ray spectroscopy (EDS) measurements demonstrate the high quality of this method for everyday use of TES EDS detectors in material analysis. However, because the method relies only on a few very general assumptions, it should also be useful for other kinds of TES detectors.

H+ and He2 + induced W L X‐rays intensity ratios: part I, Si(Li) data and EDS high resolution insight

“…Apart from experiment H + ‐X‐ray microcalorimeter spectrometer (XMS), all experiments were carried out at the 2.5 MV Van de Graaff standard PIXE set‐up using a 150 eV Si(Li) detector, the He 2 + ‐2002 used Link Si(Li), and in all the other cases, a Gresham Sirius Si(Li) was used. H + ‐XMS experiment was carried out at the 3.0 MV Tandetron HRHE‐PIXE set‐up and made use of the Vericold Technologies GmbH POLARIS EDS high‐resolution XMS installed at ITN in 2008 (presently CTN). This detector has a resolution of 18 eV for the K α 1 of Al.…”

A Highly Linear Calibration Metric for TES X-ray Microcalorimeters

“…To define the E Joule metric, which is also referred to as E ETF 20 18 , we start with the standard "one-body" thermal model describing this system 20 21 :…”

Degradation in molybdenum thin films and Mo/AuPd bilayers and its reduction by sidewall passivation

“…Making use of the proximity effect [5], the critical superconducting temperature (T c ) is tunable over a wide range below the T c of sputtered Mo (in our case around 900 mK) by varying the thickness ratio of the layers (see figure 1). We use a gold-palladium (AuPd) alloy of 50 atomic per cent (at.%) each as the normal metal in order to cover the full temperature range of usual TES applications (≈100 mK up to several hundred mK) [6,7]. Compared to Mo/Cu or Mo/Au bilayers, the stronger suppression of T c by the AuPd allows for thinner layers and thus easier production especially in the range of a few hundred mK [8].…”