Hydrogen Isotope Technology - HYTEC

This project deals with quantitative hydrogen-helium isotope analysis by means of mass spectrometry, one of the main diagnostic tasks in fusion research. A novel method (Vector-Mass-Spectrometry - VMS) has been developed, allowing a complete decomposition of hydrogen-helium isotope mass spectra obtained by low-resolution quadrupole mass spectrometers. The basic idea of this method and first results are explained in: R. Dobrozemsky, J. Vac. Sci. Technol. A10(4) (1992) 2661. During project T2.3/T277 of the Association EURATOM-OeAW, a VMS system has been installed at ASDEX Upgrade (MPI Garching) and operated for a period of two years.

This task is carried out within Association Euratom - OeAW.

Beryllium Technology

This project deals with the outgassing behaviour and other vacuum properties of beryllium (Be), one of the candidates for the first wall of nuclear fusion reactors. Measurements are carried out by means of a uhv gas-analysis system with the SGAP-method implemented, aiming at outgassing studies on small Be samples at rather low temperatures (300°C to 400°C).

This task is carried out within Association Euratom - OeAW.

Atmospheric Adsorption Phenomena

Gas-surface-interactions in atmosphere, among them water-vapor adsorption, are of crucial importance for many industrial production processes. To cope with the many challenges of this task, among them the needs for quantitative measurements of water coverages in atmosphere, Tritium-Tracer-Technique (TTT) has been introduced to surface physics. In the first step of the project, tritiated water ("HTO") and liquid-scintillation counting technique are utilized, allowing a precise measurement of adsorbed water quantities down to one percent of a "monolayer" on almost any kind of surface. First results are published in: R. Dobrozemsky, Vacuum 46 (1995) 789. It was found that the water adsorption capacities depend - to a great extend - on the cleanliness of the surfaces, and that water sojourn times in vacuum are much longer than in atmosphere.

Vacuum Calibration

This project deals with in-situ calibration of total- and partial-pressure gauges by means of the dynamic gas-expansion method. Precise quantities of pure gases (or mixtures of up to three gases), defined by a capacity diaphragm gauge inside a small "calibration volume", can be admitted to the vacuum system at any time during a measurement or during calibration procedures. Details can be found, e.g., in: R. Dobrozemsky, Vacuum 41 (1988) 950. Methods for in-situ calibration of water and oil vapors are under development.