Search results for "Transition-edge sensor"
showing 8 items of 8 documents
Characterizing a dc-SQUID and a Mo/TiW/Cu -trilayer transition-edge sensor array
2017
Tutkielmassa määritettiin uuden suprajohtavan kvantti-interferenssilaitteen ja 256 pikseliä sisältävän sirun transitioreunailmaisimien ominaisuuksia. Komponentit vaativat erittäin matalia lämpötiloja ja suojauksen suurilta magneettikentiltä muuttuakseen suprajohtaviksi. Tärkeimmät mitatut ominaisuudet olivat suprajohtavan kvantti-interferenssilaitteen signaalin vahvistuskerroin sekä kohina ja transitioreunailmaisimen transitiolämpötila, normaalitilan vastus, virta-jännite-käyttäytyminen, sekä kohina. Motivaationa tutkimukselle oli etsiä käytetyn mittalaite kokonaisuuden herkkyyden rajat sekä pyrkiä sovittamaan teoreettista mallia transitioreunailmaisimen kohinan ymmärtämiseksi. Korkean taaj…
Transition-Edge Sensors for Particle Induced X-ray Emission Measurements
2013
In this paper we present a new measurement setup, where a transitionedge sensor detector array is used to detect X-rays in particle induced X-ray emission measurements with a 2 MeV proton beam. Transition-edge sensors offer orders of magnitude improvement in energy resolution compared to conventional silicon or germanium detectors, making it possible to recognize spectral lines in materials analysis that have previously been impossible to resolve, and to get chemical information from the elements. Our sensors are cooled to the operation temperature (65 mK) with a cryogen-free adiabatic demagnetization refrigerator, which houses a specially designed X-ray snout that has a vacuum tight window…
A new beamline for energy-dispersive high-resolution PIXE analysis using polycapillary optics
2019
Abstract A new beamline for high energy resolution PIXE measurements is presented. This new setup includes options for both in-air and vacuum measurements. For the high energy resolution transition-edge sensor array, a polycapillary lens is used for detecting low-energy X-rays down to 0.5 keV and to increase the effective solid angle. X-ray transmission of the polycapillary lens was characterized using two calibration standards. The gain obtained by adding a polycapillary lens was 1.6–2.3 at energies between 2.1 keV and 4.5 keV. From 1.04 to 1.74 keV the gain is increased to 2.1–3.0, and at energies 4.9–8.0 keV the gain is between 1.6 and 0.65. The measured gain agreed well with theoretical…
Fluctuation-Limited Noise in a Superconducting Transition-Edge Sensor
2003
In order to investigate the origin of the until now unaccounted excess noise and to minimize the uncontrollable phenomena at the transition in x-ray microcalorimeters we have developed superconducting transition-edge sensors into an edgeless geometry, the so-called Corbino disk, with superconducting contacts in the center and at the outer perimeter. The measured rms current noise and its spectral density can be modeled as resistance noise resulting from fluctuations near the equilibrium superconductor-normal metal boundary. Peer reviewed
Development and applications of transition-edge sensors
2015
This thesis focuses on the theory, development and applications of Transition- Edge Sensor (TES) arrays. The main results are the design and development of a fabrication process for a 256 pixel X-ray TES detector with a novel geometry and the development of a measurement setup for TES detectors used in elemental analysis with Particle Induced X-ray Emission (PIXE) measurements. In the early stages of this thesis we fabricated a small scale 32 pixel TES array, but for an actual application purposes the pixel count and the consistency of the fabrication needs to be higher. The cleanroom facilities in the Nanoscience Center are well suited for basic research but they are not suitable for a waf…
Large 256-Pixel X-ray Transition-Edge Sensor Arrays With Mo/TiW/Cu Trilayers
2015
We describe the fabrication and electrical characterization of 256-pixel X-ray transition-edge sensor (TES) arrays intended for materials analysis applications. The processing is done on 6-in wafers, providing capabilities on a commercial scale. TES films were novel proximity coupled Mo/TiW/Cu trilayers, where the thin TiW layer in between aims to improve the stability of the devices by preventing unwanted effects such as Mo/Cu interdiffusion. The absorber elements were electrodeposited gold of thickness 2 μm. The single-pixel design discussed here is the so-called Corbino geometry. Most design goals were successfully met, such as the critical temperature, thermal time constant, and transit…
Simultaneous Noise and Impedance Fitting to Transition-Edge Sensor Data Using Differential Evolution
2020
We discuss a robust method to simultaneously fit a complex multi-body model both to the complex impedance and the noise data for transition-edge sensors. It is based on a differential evolution (DE) algorithm, providing accurate and repeatable results with only a small increase in computational cost compared to the Levenberg–Marquardt (LM) algorithm. Test fits are made using both DE and LM methods, and the results compared with previously determined best fits, with varying initial value deviations and limit ranges for the parameters. The robustness of DE is demonstrated with successful fits even when parameter limits up to a factor of 10 from the known values were used. It is shown that the…
Transition-edge sensors for particle-induced X-ray emission spectrometry
2018
A transition-edge sensor array has been applied to particle-induced X-ray emission. We have characterized the detector for quantitative analysis and obtained minimum detection limit over two orders of magnitude better compared to a silicon drift detector. We have also studied chemical effects in analysis of Ti, TiO2 and TiN using proton and heavy ion beams. A chemical shift for TiO2 was observed in proton measurements, and relative multiple ionization X-ray satellite line intensities changed between metallic Ti and other compounds with heavy ions. Detection of low energy X-rays down to 0.5 keV was achieved by installing a polycapillary lens in front of the transition-edge sensor array in ex…