A rapid-scanning polychromator for time-resolved temperature and radius measurements in 40 kA SF₆arcs

Abstract

A two-channel rapid-scanning polychromator is described which provides time and space resolution of visible-wavelength SF6 arc emission lines. Use of a multiple-entrance-slit assembly and divided-fibre optics enables five sequential sets of side-on line profiles to be obtained spaced over 30 mu s. A novel method of polychromator exit slit construction and precision alignment is used, and the side-on data are digitised and stored prior to computer processing to obtain the instantaneous radial temperature profiles.