Im Rahmen der DPG-Frühjahrstagung der Sektion Kondensierte Materie lädt die DVG gemeinsam mit dem DPG Fachverband Vakuumphysik und -Technik VA zum
Tag des Vakuums
Die Veranstaltung findet am 1. April 2019 an der Universität Regensburg unter dem Leitthema
Metrology - the key for success in research and industry
Metrology - The key for success in research and industry
- Dr. Joachim H. Ullrich (Präsident PTB), plenary talk
- Karl Jousten (PTB), invited talk
- Weitere Vorträge (siehe nächste Folie)
- Panel discussion
Registrierung über DPG-Webseite
Montag (Raum H6)
Plenary Talk: Linking the International System of Units to Fundamental Constants
Joachim Ullrich (PTB)
In November 2018, the General Conference for Weights and Measures, CGPM, established by the Metre Convention in 1875, decided on the revision of the International System of Units (SI). The signatory states of the Metre Convention represent about 98 % of the world's economic power and, thus, the SI is the very foundation of global, international trade and the reliability of measurements worldwide. As suggested by Max Planck when postulating the "Planck constant" in 1900, the revised SI shall be based on fixing the numerical values of "defining constants": the velocity of light, the elementary charge, the Boltzmann, Avogadro and the Planck constants, the Cs hyperfine clock transition and the luminous efficacy. The revision is based on our present theoretical understanding of the microscopic world and is meant to ensure that the units are valid and realizable "for all times and civilizations, throughout the Universe" as envisioned by Max Planck. The talk will give an overview on the revised SI and its advantages as compared to the previous definitions, focusing in particular on future perspectives for innovative technologies. The question of whether the "defining fundamental constants" are indeed constant in time and the topic of next generation clocks will be addressed briefly.
VA 2: Vacuum Metrology
Invited Talk: Vacuum metrology and its impact on research and industry
Karl Jousten and Matthias Bernien (PTB)
Whenever a physical quantity like vacuum pressure is being measured it is important that the indication of the instrument is in agreement with the International System of Units (SI). Normally, the user does not want to take care of this, but the manufacturers of the instruments and the calibration services need to. The measurement of vacuum covers 15 decades and needs instruments that realize quite different physical effects of pressure or gas density. While the mechanical deformation of membranes or thermal conductivity are used in rough and medium vacuum, the instruments for high and ultra-high vacuum measure the impingement rate of gas molecules or their number density in some volume. Vacuum presents the necessary environment for many research activities and industrial processes, however, just a few applications need high accuracy of the vacuum measurement. Leak rate measurements or outgassing rate measurements have to ensure that components are correctly qualified for their purpose as e.g. cardia pacemakers or components in EUV lithography. In the future, it can be expected that optical methods like laser spectroscopy and refractive index measurements will play a more important role in vacuum measurement.
Vacuum-compatible photon-counting hybrid pixel detector for WAXS, XRD and XRR in the tender X-ray range
Dieter Skroblin et al. (PTB)
Vacuum Pressure Measurement in Industrial Environments
Martin Wüest — INFICON AG
Absorption spectroscopy for process monitoring of technological plasmas
Jürgen Röpcke et al. Leibniz Institute for Plasma Science and Technology
Nothing without vacuum!
Ute Bergner — Deutsche Vakuum Gesellschaft (DVG)
Vacuum technology plays an important role in the progress of major industries. The rise of many applications enabled only by the use vacuum in the 20th century lead the foundation of vacuum societies. The roots of the German Vacuum Society founded in 1963 go back to the 1950s when physicists, engineers and others founded several organizations in order to exchange experiences and knowledge in the field of vacuum technique and physics. More than ever, vacuum technology is an essential enabler of high technologies and advances many fields of research. The talk gives an insight into the aims and activities of the DVG, its collaboration and interaction with the DPG, the IUVSTA and networking opportunities with industry.
VA 3: Gaede Prize Talk: Selina Olthoff (joint session PRV/DS/VA)
Preisträgervortrag: Absolute energy levels and interface energetics of halide perovskites
Selina Olthof, of Physical Chemsitry, University of Cologne, Luxemburger Strasse 116, 50939 Cologne
In recent years, the interest in halide perovskites rose at a rapid pace due to their tremendous success in the field of photovoltaics; but other fields, like light emitting diodes, show great potential as well. In such devices, the function and performance depend on the proper alignment of energy levels throughout the device, i.e. allowing for efficient charge transport across the various interfaces. Here, an advantage of these novel semiconductors is that the electronic structure and band gap can be readily tuned by changing the compositions of the perovskite. In this talk, I will discuss recent findings regarding the variations in electronic structure of halide perovskites measured by a combination of UV-, inverse, and x-ray photoelectron spectroscopy (PES); in this extensive study, we cover all primary lead and tin based halide systems. Combining these results with DFT calculations and a tight binding model we are able to consistently describe variations found in the electronic structure. However, not only the absolute energy levels of these materials are of interest, but also their alignment to adjacent transport layers, as interface dipoles and band bending can significantly alter the electronic landscape within a device. We also performed interface resolved PES studies on the MAPbI3 system. Comparing various bottom contacts we can show that chemical interactions, band bending, and interface dipole formation indeed play an important role in these perovskite systems
VA 4: New Vacuum Gauges - Development and Characterization
Invited Talk Development of a new wireless SAW-Pirani vacuum sensor with extended range and sensitivity
Sofia Toto and Juergen Brandner (KIT)
Vacuum sensors with a broad range are required for a number of applications. Many types of vacuum sensors already exist relying on various operating principles. One of their biggest drawback is their limited sensing range. In light of the recent technology and of the industry requirements, a new sensor aiming to sense a broader vacuum range extending from atmospheric pressure down to high vacuum has been developed. It uses state of the art microelectronics enabling efficient wireless power and signal transfer, resistant and stable materials that prevent outgassing and micromachining that allows a compact stable packaging in vacuum.
The sensor operates based on the Pirani principle and Surface Acoustic Waves (SAW-Pirani principle). A piezoelectric chip located inside a channel inserted in a vacuum environment is heated. The heat loss of the chip to its ambient through gas conduction is proportional to the number of molecules in the vacuum system. Temperature variations of the chip due to pressure changes in the vacuum chamber are detected by the change in frequency values of a crossing surface acoustic wave propagating on the surface of the chip via an interdigitated transducer. An interrogation signal is sent to the Interdigitated Transducer (IDT) and the frequency shift due to the pressure is recorded by the reflected signal. The vacuum pressure can therefore be calculated from the temperature of the heated body.
Combined total - partial pressure sensor
Mihail Granovskij et al – VACOM
VA 5: Vacuum Measurement in Technical Applications
Invited Talk : Outgassing rate measurements in practice: feasibility and comparability
Michael Flämmich et al. VACOM/TREAMS
Outgassing rate measurements have long been utilized for the qualification of the vacuum suitability of materials in laboratories worldwide. At VACOM these measurements are fully integrated in the process chain of the production and cleaning of vacuum components. By this means, outgassing rate measurements are routinely performed with residual gas analysis (RGA) systems (utilizing either the throughput or the box-in-box method) in order to verify the cleanliness of the parts, components and assemblies. In order to perform reliable, comparable and quantitative RGA measurements utilizing different RGA systems/tools, each system/tool itself needs to be calibrated, where the calibration or rather the adjustment of the utilized quadrupole mass spectrometer (QMS) is finally tipping the scales.
In this talk, we present some results of a comparison of different types of commercially available QMS that have been investigated with respect to their feasibility in qualitative and quantitative outgassing rate measurements. Although these QMS exhibit relevant differences in design (e.g. ion source, single-/double-/triple-filter, rod system, ...) that yield serious differences in their characteristics (e.g. dynamic range, (mass specific) sensitivity, detection limit, ...), it was possible to adjust these QMS to a comparable performance in RGA measurements.
Improved model for transmission probabilities of edge-welded bellows based on TPMC simulations
Marcel Krause and Joachim Wolf (KIT)
Modern Mass Spectrometry in Vacuum Applications using LEYSPEC RGAs
Stefan Lausberg (Leybold GmbH)