Messung der Oszillatorenstärken von SiI-, SiII-und SiIII-Linien im Wellenlangenbereich 1100 — 2600 Å und Vergleich des Vakuum-UV-Strahlungsnormals mit dem Kohlebogen

The oscillator strengths of 72 Si I-, Si II- and Si III-lines and multiplets in the wavelength region 1100 -2600 Å were measured in emission. The light source was a wall-stabilized arc burning in argon at atmopheric pressure into which small amounts of silicon tetrafluoride and fluorine were introduced. All oscillator strengths were measured relatively and then put on an absolute scale by using the value Anm = 1,64 · 108 sec-1 for the transition probability of the Si I-multiplet 2506 Å to 2528 Å.

The vacuum-UV intensity calibration method using the central intensities of optically thick lines in the cascade arc was extended up to the wavelength 2516 Å. In this wavelength region it could be directly compared with the radiation of the anode crater of the carbon arc. Full agreement between these two intensity standards was found.