Spektroskopische Untersuchungen über das thermodynamische Gleichgewicht der Anregung in den Plasmen kurzdauernder Impulsentladungen

Abstract

The light emission of gases conducting electric discharges is of considerable complexity. The observed phenomenas are controlled to a great part by the electric parameters of the circuit, as well as by the time constants of the specific plasma properties as the relation times for reaching Maxwellian distribution and thermal equilibrium of electrons, ions, and atoms. The influence of the nonequilibrium between the excitation and the electron temperature on the population of states was studied in short time discharges by means of singulet and triplet lines of elements of the second group of the periodic system. In these discharges a nonequilibrium was found between the excitation and the el~tron temperature. While the time constant measured for the cooling of the electron gas was found to 7 9 10 -7 s in a discharge switched off 9 9 10 -7 s past the ignition the minimal time constant of relaxation of excitation is equal to the life time of the 2p 2 state --this value of cadmium being 2.4 9 10 -6 s --. The use of Boltzmann and Saha equation must be considered very carefully in this type of short time discharges.