A vacuum spark discharge source with aluminum electrodes is constructed to obtain highly ionized aluminum line spectra in the 50-100 Å region. It is similar to BRV sources in having a trigger electrode to initiate the discharge ; it differs from them in that the radiation from the discharge channel is observed in the radial direction. The highest ionization stage observed is Typical spectra are shown in a form of densitometer trace. A simple plasma model is assumed to discuss the possibility of obtaining more aluminum lines in the 50-100 Å region.
A new method is described of the Zeeman effect atomic absorption analysis by means of observation in the direction transverse to a magnetic field without using any isotope. When a light source is placed in a suitable magnetic field and observed in the direction transverse to it, it is possible to make the π components coincide with an atomic absorption line and to displace the σ components from it. The π components are used as the probe light for the measurement of absorption and the σ components as the reference light for the correction of scattering and molecular absorption. Though the mercury resonance line at 2536.5 Å has complex hyperfine structure, this method permits the use of a lamp of naturally occurring mercury. Background absorption can be corrected accurately with our method, allowing analyses of mercury contents in various samples without any chemical pretreatment. This method is generally applicable also to accurate and highly sensitive analyses of elements other than mercury. A high-resolution spectrophotometer with magnetic scanning was used to observe atomic absorption profiles under various conditions.