The energies of the n2P1/2,3/2 level series in 39K (9 ⩽ n ⩽ 21) and 85Rb (13 ⩽ n ⩽ 68) have been measured using frequency-doubled cw dye laser radiation, a thermionic detector and a high-precision vacuum-wavemeter. By means of a Rydberg-Ritz fitting procedure accurate quantum defect data and ionization limits are given. The ionization limits are in agreement with the limits derived from energy data of other l-series which have been measured recently with laser spectroscopy techniques.The compact Rydberg-Ritz formulas can serve as handy secondary wavelength standards with high precision.A compilation of the most accurate Rydberg-Ritz coefficient of all alkali term series with l ⩽ 3 is presented and the present status of alkali quantum defect data is discussed. This set of data includes also recent measurements of 133Cs n2S1/2 and n2D3/2,5/2 levels and of some low-lying 7Li levels.

Laser-induced emission spectral analysis (LIESA, a registered trademark of instruments developed by Krupp), better known in the literature as laser microanalysis or laser-induced breakdown spectroscopy, is a suitable method for the direct in-process measurement of elemental concentrations in various solid and liquid materials. This method has been developed recently by Krupp for in-process quality assurance and process control in different industrial branches such as steel production ahd plant making. As a result several LIESA instruments have already been developed or are under development for marketing. In all cases on-line and in-process elemental analysis of materials at various stages of production yield information on the quality of the material and the fabrication process. The beam of a pulsed high-power laser (irradiance: 1 x 108-5 x lo9 W cm-2), focused onto the solid or liquid sample surface in an ambient gas atmosphere of normal pressure (focus areazablation area, 0.1 -6 mm2), produces a hot bright plasma (early electron temperatures, 20 000-30 000 K). The emitted plasma light is observed end-on and passes by way of an optical fibre bundle to a spectrometer, where it is detected in the focal plane by means of an optical multichannel analyser with high time resolution (on the microsecond scale). A fast computer evaluates the measured spectra and calculates the element concentrations via calibration procedures. Relative detection limits of between 10 and 100 ppm can be achieved for most of the detectable elements in various matrices (steel, rubber, rock and glass). Procedures are available to convert relative measurements with relative standard deviations of between 1 and 2% into absolute concentration values with relative accuracies of about 3%.

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Very accurate measurements of the n aS1/2 (n = 9-30), n 2P1/2, 3/2 (n = 9-50) and n 2D3/2, 5/2 (n=5, 8-32) energy levels in CsI have been performed in the wavelength-range 6,379 ,~<2 < 7,432 • with a high-precision vacuum-wavemeter using either Doppler-free two-photon spectroscopy or Doppler-limited one-photon spectroscopy with a frequency-doubling crystal. Thermionic detectors were used throughout the experiments. By fitting the experimental energy values to extended Rydberg-Ritz formulas, accurate quantum defect data and series limits are given. The ionization energy E~ =31,406.4710(7) cm -1 was adopted to be the best fit value, differing significantly from most recent evaluations of other authors, but agreeing well with former, less accurate measurements performed in our laboratory.