PULSED METASTABLE ATOM SOURCE FOR LOW VAPOR-PRESSURE METALS

The basic design and most relevant experimental conditions of a pulsed metastable atomic-beam oven are described. The stainless steel oven is suitable for vaporising metals and salts up to around 1400 K producing intense beams of metastable alkaline-earth atoms when pulsed or CW low voltage discharges are used. Several applications using atomic calcium in its 3P and 1D electronic state are reported. The beam characterisation and discharge efficiency have been measured by time-of-flight or laser-induced fluorescence techniques. In addition, a method of changing the metastable n 3P/n1D ratio, by raising the oven temperature, is described which looks very promising for the study of electronic selectivity in reactive collision processes. Several spectroscopic applications for atomic and molecular beam determinations are reported.