us (NAVAJO) Project 18.3 - Spectroscopy = H. Stewart F,. Harrington 4H. Stewart OBJECTIVE The N.R.L. phase of the Redwing chord experiments was planned as a continuation of the spectrographic studies of the absorbing agents formed around a nuclear detonation by excitations, disassociations and recombinations of the air molecules exposed to the high energy particles generated by the explosion. A particular purpose of the ex- periments was to carry out such investigations with better time and spectral resolution than had been achieved in the past. In addition to the chord work it was planned to study the spectrum of the bomb light at minimum time with good wavelength resolution and to investigate the spectrum of Teller light with improved time and wavelength resolution. INTRODUCTION A chord experiment is one in which the spectral characteristics of a light source as a function of time are observed under conditions such that the gamma rays and neutrons from an exploding weapon cross the line of sight from the observing station to the light source. ° . oy te - 99 -