Search results for "Technik"
showing 10 items of 94 documents
Suppression of Penning discharges between the KATRIN spectrometers
2020
The KArlsruhe TRItium Neutrino experiment (KATRIN) aims to determine the effective electron (anti)neutrino mass with a sensitivity of $0.2\textrm{ eV/c}^2$ (90$\%$ C.L.) by precisely measuring the endpoint region of the tritium $\beta$-decay spectrum. It uses a tandem of electrostatic spectrometers working as MAC-E (magnetic adiabatic collimation combined with an electrostatic) filters. In the space between the pre-spectrometer and the main spectrometer, an unavoidable Penning trap is created when the superconducting magnet between the two spectrometers, biased at their respective nominal potentials, is energized. The electrons accumulated in this trap can lead to discharges, which create a…
Gamma-induced background in the KATRIN main spectrometer
2019
The KATRIN experiment aims to measure the effective electron antineutrino mass $$m_{\overline{\nu }_e}$$ mν¯e with a sensitivity of $${0.2}\,{\hbox {eV}/\hbox {c}^2}$$ 0.2eV/c2 using a gaseous tritium source combined with the MAC-E filter technique. A low background rate is crucial to achieving the proposed sensitivity, and dedicated measurements have been performed to study possible sources of background electrons. In this work, we test the hypothesis that gamma radiation from external radioactive sources significantly increases the rate of background events created in the main spectrometer (MS) and observed in the focal-plane detector. Using detailed simulations of the gamma flux in the e…
Consistent device simulation model describing perovskite solar cells in steady-state, transient, and frequency domain
2019
This document is the Accepted Manuscript version of a Published Work that appeared in final form in ACS Applied Materials & Interfaces, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see https://pubs.acs.org/doi/10.1021/acsami.9b04991
Advanced stochastic control systems with engineering applications
2014
1 School of Astronautics, Harbin Institute of Technology, Harbin, Heilongjiang, China 2 School of Electrical and Electronic Engineering, The University of Adelaide, SA 5005, Australia 3 Department of Engineering, Faculty of Engineering and Science, University of Agder, 4898 Grimstad, Norway 4 Institute of Automation and Complex Systems, University of Duisburg-Essen, Duisburg, Germany 5 College of Automation, Chongqing University, Chongqing 400044, China
Der historische Studentenkarzer der Universität Lettlands
2021
Die Universität Lettlands beherbergt das historische Studentenkarzer, ein Zeugnis des täglichen Lebens der Studenten während ihres Studiums aus dem 19. Jahrhundert. Der Studentenkarzer geht auf das mittelalterliche Deutschland zurück, als die Universitäten das Recht hatten, Studenten für Vergehen während des Studiums in Zellen einzusperren. Die Idee wurde im 19. Jahrhundert mit der Ausbreitung des deutschen akademischen Einflusses im Baltikum verwirklicht. Dieses historische Phänomen geriet während der sowjetischen Besatzung in Vergessenheit oder wurde verfälscht, ist aber nun rehabilitiert worden. Das Museum der Universität Lettlands und der Akademische Verlag der Universität Lettlands hab…
Latvijas Universitātes vēsturiskais studentu karceris
2021
The University of Latvia has 19 th-century historical witness regarding the daily life of students during studies - the historical student solitary confinement cell. The origins of the student solitary confinement cell are found in medieval Germany, when universities were entitled to detain students into cells for the misdeeds during the studies. The idea was realized in the 19th century, which coincided with the time when German academic influence spread in the Baltics. During the occupation of the USSR, this history phenomenon was forgotten or distorted, but it is now rehabilitated. The Museum of the University of Latvia with the University of Latvia Academic Press has issued booklet, whi…
Historical University of Latvia student solitary confinement cell: video
2021
The University of Latvia has 19th-century historical witness regarding the daily life of students during studies - the historical student solitary confinement cell. The origins of the student solitary confinement cell are found in medieval Germany, when universities were entitled to turn students into cells for the misdeeds during the studies. The idea was realized in the 19th century, which coincided with the time when German academic influence spread in the Baltics. During the occupation of the USSR, this history phenomenon was forgotten or distorted, but it is now rehabilitated. The Museum of the University of Latvia has filmed a video with subtitles in English about the student solitary…
Highly sensitive superconducting circuits at ∼700 kHz with tunable quality factors for image-current detection of single trapped antiprotons
2016
We developed highly-sensitive image-current detection systems based on superconducting toroidal coils and ultra-low noise amplifiers for non-destructive measurements of the axial frequencies (550$\sim$800$\,$kHz) of single antiprotons stored in a cryogenic multi-Penning-trap system. The unloaded superconducting tuned circuits show quality factors of up to 500$\,$000, which corresponds to a factor of 10 improvement compared to our previously used solenoidal designs. Connected to ultra-low noise amplifiers and the trap system, signal-to-noise-ratios of 30$\,$dB at quality factors of > 20$\,$000 are achieved. In addition, we have developed a superconducting switch which allows continuous tu…
Sympathetic cooling of protons and antiprotons with a common endcap Penning trap.
2017
We present an experiment to sympathetically cool protons and antiprotons in a Penning trap by resonantly coupling the particles to laser cooled beryllium ions using a common endcap technique. Our analysis shows that preparation of (anti)protons at mK temperatures on timescales of tens of seconds is feasible. Successful implementation of the technique will have immediate and significant impact on high-precision comparisons of the fundamental properties of protons and antiprotons. This in turn will provide some of the most stringent tests of the fundamental symmetries of the Standard Model.
Sources, determination, monitoring, and transport of carbonaceous aerosols in Mainz, Germany
1998
Abstract Total atmospheric particulate matter, total carbon (TC), and black carbon (BC) were measured over two periods, spring and summer 1994, at a sampling location in Mainz, Germany. An optical (aethalometer) and a thermal method were used to determine BC since previous studies have shown that the optical method is dependent on the source of aerosols. The thermal method chosen for calibration enables the determination of molar hydrogen to carbon ratios for total particulate carbon and BC if quartz fiber filters were pre-treated at 850°C for 4 h. A specific attenuation cross-section of ≈7 m 2 g -1 for BC on the aethalometer filter was calculated which lies between values determined for c…