Development and characterization of two-dimensional metallic magnetic calorimeter arrays for the high-resolution X-ray spectroscopy

In the framework of this thesis the new two-dimensional detector array maXs30 was developed, fabricated and characterized. It is optimized for high-resolution X-ray spectroscopy in the energy range up to 30 keV and consists of 8x8 individual metallic magnetic calorimeters. These detectors combine the good energy resolution of crystal spectrometers and the large energy bandwidth of semiconductor detectors and measure the energy of each absorbed photon by the resulting temperature change. This change is converted to a change of magnetization by the paramagnetic alloy Ag:Er, which is read out by sensitive SQUID magnetometers. The detector can be mounted on the side arm of a mobile dry dilution refrigerator and a new 32 channel acquisition system has been developed for this array. The intrinsic energy resolution of the maXs30 detector was measured to be 7.9 eV (FWHM) and a resolving power of almost 3000 was achieved for X-rays with an energy of 60 keV. The complete maXs system was successfully tested during several experiments at the heavy ion storage ring ESR at the GSI, where the Lyman series of Xe53+ and the Balmer series of U89+ were investigated

Reallocating Uncertainty in Incumbent Firms through Digital Platforms: The Case of Google’s Automotive Ecosystem Involvement

This research examines how incumbent firms decide on the degree of involvement of technology players in their digital strategies, by integrating insights from digital innovation and digital platform research. We conducted an embedded case study on the adoption of Google’s Android Automotive OS and Google Automotive Services by the automotive industry, using semi-structured interviews with industry experts and senior decision-makers. We build on affordance-actualization theory to develop a grounded model of uncertainty reallocation consisting of five aggregate dimensions: (1) external digital platform by tech firm, (2) incumbent firm and its goals, (3) uncertainty tradeoffs and affordance of reallocation, (4) strategic actions by incumbent firm, and (5) short- and long-term outcomes. Our results provide valuable insights into the selection of non-binary platform strategies and the effects of various levels of technology firm involvement. This addition to the knowledge base of the information systems discipline provides practical guidance for incumbent firms navigating digital transformation

Measuring Magnetic 1/f Noise in Superconducting Microstructures and the Fluctuation-Dissipation Theorem

The performance of superconducting devices like qubits, SQUIDs, and particle detectors is often limited by finite coherence times and 1/f noise. Various types of slow fluctuators in the Josephson junctions and the passive parts of these superconducting circuits can be the cause, and devices usually suffer from a combination of different noise sources, which are hard to disentangle and therefore hard to eliminate. One contribution is magnetic 1/f noise caused by fluctuating magnetic moments of magnetic impurities or dangling bonds in superconducting inductances, surface oxides, insulating oxide layers, and adsorbates. In an effort to further analyze such sources of noise, we have developed an experimental set-up to measure both the complex impedance of superconducting microstructures, and the overall noise picked up by these structures. This allows for important sanity checks by connecting both quantities via the fluctuation-dissipation theorem. Since these two measurements are sensitive to different types of noise, we are able to identify and quantify individual noise sources. The superconducting inductances under investigation form a Wheatstone-like bridge, read out by two independent cross-correlated dc-SQUID read-out chains. The resulting noise resolution lies beneath the quantum limit of the front-end SQUIDs and lets us measure noise caused by just a few ppm of impurities in close-by materials. We present measurements of the insulating SiO2 layers of our devices, and magnetically doped noble metal layers in the vicinity of the pickup coils at T = 30 mK - 800 mK and f = 1 Hz - 100 kHz.Comment: 13 pages, 5 figure

Towards Precision Muonic X-Ray Measurements of Charge Radii of Light Nuclei

Precision studies of the properties of nuclei are essential both for understanding nuclear physics at low energy, and for confronting experiment and theory in simple atomic systems. Such comparisons advance our understanding of bound-state quantum electrodynamics and are useful for searching for new physics beyond the Standard Model. The energy levels of muonic atoms are highly susceptible to nuclear structure, especially to the RMS charge radius. The radii of the lightest nuclei ($Z=1,2$) have been determined with high accuracy via laser spectroscopy in muonic atoms, while those of medium mass and above, from X-ray spectroscopy with semiconductor detectors. In this communication we present a new experiment aiming at precision measurements of the radii of light nuclei $3 \leq Z \leq 10$ via single-photon energy measurements with cryogenic microcalorimeters; a quantum sensing technology capable of high efficiency and outstanding resolution for low-energy X-rays

Эпидемиологические исследования в сексологии

Представлены результаты эпидемиологического исследования, позволившие автору на примере обследования 1000 человек популяции из западного региона Украины сформулировать основные закономерности изменения отношения к браку и сексуального поведения мужчин и женщин в современном обществе.The findings of epidemiological study, which allowed the author to formulate main regularities of the changes in the attitude to the marriage and sexual behavior of men and women in the contemporary society on the example of the examination of 1000 persons from the western regions of Ukraine, are presented

Exploitation of the Timing Capabilities of Metallic Magnetic Calorimeters for a Coincidence Measurement Scheme

In this report, we compare two filter algorithms for extracting timing information using novel metallic magnetic calorimeter detectors, applied to the precision X-ray spectroscopy of highly charged ions in a storage ring. Accurate timing information is crucial when exploiting coincidence conditions for background suppression to obtain clean spectra. For X-rays emitted by charge-changing interactions between ions and a target, this is a well-established technique when relying on conventional semiconductor detectors that offer a good temporal resolution. However, until recently, such a coincidence scheme had never been realized with metallic magnetic calorimeters, which typically feature much longer signal rise times. In this report, we present optimized timing filter algorithms for this type of detector. Their application to experimental data recently obtained at the electron cooler of CRYRING@ESR at GSI, Darmstadt is discussed

Comparing United States and Canadian population exposures from National Biomonitoring Surveys: Bisphenol A intake as a case study

The Centers for Disease Control and Prevention provides biomonitoring data in the United States as part of the National Health and Nutrition Examination Survey (NHANES). Recently, Statistics Canada initiated a similar survey — the Canadian Health Measures Survey (CHMS). Comparison of US and Canadian biomonitoring data can generate hypotheses regarding human exposures from environmental media and consumer products. To ensure that such comparisons are scientifically meaningful, it is essential to first evaluate aspects of the surveys' methods that can impact comparability of data. We examined CHMS and NHANES methodologies, using bisphenol A (BPA) as a case study, to evaluate whether survey differences exist that would hinder our ability to compare chemical concentrations between countries. We explored methods associated with participant selection, urine sampling, and analytical methods. BPA intakes were also estimated to address body weight differences between countries. Differences in survey methods were identified but are unlikely to have substantial impacts on inter-survey comparisons of BPA intakes. BPA intakes for both countries are below health-based guidance values set by the US, Canada and the European Food Safety Authority. We recommend that before comparing biomonitoring data between surveys, a thorough review of methodologic aspects that might impact biomonitoring results be conducted

The Electron Capture in 163^{163} Ho Experiment - a Short Update

The definition of the absolute neutrino mass scale is one of the main goals of the Particle Physics today. The study of the end-point regions of the β- and electron capture (EC) spectrum offers a possibility to determine the effective electron (anti-)neutrino mass in a completely model independent way, as it only relies on the energy and momentum conservation. The ECHo (Electron Capture in 163Ho) experiment has been designed in the attempt to measure the effective mass of the electron neutrino by performing high statistics and high energy resolution measurements of the 163 Ho electron capture spectrum. To achieve this goal, large arrays of low temperature metallic magnetic calorimeters (MMCs) implanted with with 163Ho are used. Here we report on the structure and the status of the experiment

Towards an Intrinsic Doppler Correction for X-ray Spectroscopy of Stored Ions at CRYRING@ESR

We report on a new experimental approach for the Doppler correction of X-rays emitted by heavy ions, using novel metallic magnetic calorimeter detectors which uniquely combine a high spectral resolution with a broad bandwidth acceptance. The measurement was carried out at the electron cooler of CRYRING@ESR at GSI, Darmstadt, Germany. The X-ray emission associated with the radiative recombination of cooler electrons and stored hydrogen-like uranium ions was investigated using two novel microcalorimeter detectors positioned under 0∘ and 180∘ with respect to the ion beam axis. This new experimental setup allowed the investigation of the region of the N, M → L transitions in helium-like uranium with a spectral resolution unmatched by previous studies using conventional semiconductor X-ray detectors. When assuming that the rest-frame energy of at least a few of the recorded transitions is well-known from theory or experiments, a precise measurement of the Doppler shifted line positions in the laboratory system can be used to determine the ion beam velocity using only spectral information. The spectral resolution achievable with microcalorimeter detectors should, for the first time, allow intrinsic Doppler correction to be performed for the precision X-ray spectroscopy of stored heavy ions. A comparison with data from a previous experiment at the ESR electron cooler, as well as the conventional method of conducting Doppler correction using electron cooler parameters, will be discussed