Use of Space-Charge-Amplification Techniques in the Absorption Spectroscopy of Cs and Cs₂

Space-charge amplification of the direct and indirect ionization resulting from photoabsorption in alkali-metal vapor is shown to provide a useful complement to the conventional techniques of absorption spectroscopy. Because of its inherently greater sensitivity, this technique is particularly useful in spectroscopic applications involving weak transitions such as those to highly excited states or absorptive transitions from excited states of low population. This paper reports the use of this technique to extend prior measurements of the oscillator strengths of the (6²S→n ²P) series in Cs, the n ²D doublet separations, and the photoionization spectrum of Cs₂.