Developments in Apparatus and Techniques for Time-Resolved Spectroscopy

Abstract

Spectra dispersed only according to wavelength have a limited physical meaning since they fail to reveal the changes in the light source in time. Electronically controlled spectroscopic light sources operating with high precision in time make possible the production of time-resolved spectra, which can be represented as a function of wavelength and time. Resolution in time is accomplished with the aid of rotating mirrors and disks, fitted in the optical system of conventional spectrographs. The time-revolving element and the light source are synchronized magnetically or by means of a photocell. The light source is controlled by a trigger signal generator driven by a photocell or a magnetic coil. The rotating mirror or disk, driven by a synchronous motor from the mains voltage, is incorporated in a mechanical apparatus, making possible electric phase adjustments. Several details of time-resolved spectra of high- and low-voltage sparks and of ac arcs are demonstrated.