Design and performance of a vacuum-UV simulator for material testing under space conditions

This paper describes the construction and performance of a VUV-simulator that has been designed to study degradation of materials under space conditions. It is part of the Complex Irradiation Facility at DLR in Bremen, Germany, that has been built for testing of material under irradiation in the complete UV-range as well as under proton and electron irradiation. Presently available UV-sources used for material tests do not allow the irradiation with wavelengths smaller than about $115$ nm where common Deuterium lamps show an intensity cut-off. The VUV-simulator generates radiation by excitation of a gas-flow with an electron beam. The intensity of the radiation can be varied by manipulating the gas-flow and/or the electron beam. The VUV simulator has been calibrated at three different gas-flow settings in the range from $40$ nm to $410$ nm. The calibration has been made by the Physikalisch-Technische Bundesanstalt (PTB) in Berlin. The measured spectra show total irradiance intensities from $24$ to $58$ mW$\rm{m^{-2}}$ (see Table 4.2) in the VUV-range, i.e. for wavelengths smaller than $200$ nm. They exhibit a large number of spectral lines generated either by the gas-flow constituents or by metal atoms in the residual gas which come from metals used in the source construction. In the range from $40$ nm to $120$ nm where Deuterium lamps are not usable, acceleration factors of $3$ to $26.3$ Solar Constants are reached depending on the gas-flow setting. The VUV-simulator allows studies of general degradation effects caused by photoionization and photodissociation as well as accelerated degradation tests by use of intensities that are significantly higher compared to that of the Sun at $1$ AU

Planar n-in-n quad module prototypes for the ATLAS ITk upgrade at HL-LHC

In order to meet the requirements of the High Luminosity LHC (HL-LHC), it will be necessary to replace the current tracker of the ATLAS experiment. Therefore, a new all-silicon tracking detector is being developed, the so-called Inner Tracker (ITk). The use of quad chip modules is intended in its pixel region. These modules consist of a silicon sensor that forms a unit along with four read-out chips. The current ATLAS pixel detector consists of planar n-in-n silicon pixel sensors. Similar sensors and four FE-I4 read-out chips were assembled to first prototypes of planar n-in-n quad modules. The main focus of the investigation of these modules was the region between the read-out chips, especially the central area between all four read-out chips. There are special pixel cells placed on the sensor which cover the gap between the read-out chips. This contribution focuses on the characterization of a non-irradiated device, including important sensor characteristics, charge collection determined with radioactive sources as well as hit efficiency measurements, performed in the laboratory and at testbeams. In addition, first laboratory results of an irradiated device are presented

Möglichkeiten zur Bildung eines Regionalindex Wohnkosten unter Verwendung von Angebotsdaten

Der Rat für Sozial- und Wirtschaftsdaten hat am 21. März unter dem Titel „Weißer Fleck Regionale Preisindizes – Wie kann die Wissenslücke geschlossen werden?“ einen Projektaufruf veröffentlicht, um Möglichkeiten zur Bildung regional differenzierter Preisindizes zu beleuchten und mittelfristig die entsprechende Datenverfügbarkeit zu verbessern. Dabei sind vor allem Güter und Leistungen von Bedeutung, die mit Blick auf regional unterschiedliche Lebenshaltungskosten ein hohes Gewicht haben. Im Zuge dieses Aufrufs hat der Rat für Sozial- und Wirtschaftsdaten empirica damit beauftragt, mit einer Expertise für den Bereich „Wohnkosten“ ein Mosaik zum Gesamtbild beizusteuern. Wohnkosten spielen – das wird auch im Projektaufruf deutlich – im Kontext regionaler Preisindizes eine entscheidende Rolle, denn zum einen geben Mieterhaushalte fast während des gesamten Lebenszyklus rund 20% ihres Nettoeinkommens für das Wohnen aus (Kaltmiete). Zum anderen sind auch die regionalen Unterschiede, beispielsweise zwischen München und peripheren Regionen Ostdeutschlands, erheblich.

Treibhausgasflüsse induziert durch differenzierte Bodenbearbeitung und Düngung in einer Kleegras – Umbruch – Winterweizen Sequenz unter Biobedingungen

Reduced tillage is technically a challenging task in organic arable farming due to weeds but also concerning the destruction of grass-clover leys. It changes the stratification of organic matter within soils which might lead to more compacted, less aerated soils and thus to higher greenhouse gas emissions. There are hardly any data existing assessing organic reduced tillage systems. Nitrous oxide and methane fluxes were therefore monitored in a two-year period including a grass-clover ley, its destruction and winter wheat. Results are presented