Time-Resolved Intensity Patterns of the Radiation from Various Regions of a Vacuum Spark Discharge

Abstract

Time-resolved intensity patterns of some lines of the second and third spectra of carbon from three different regions of a high-current vacuum spark discharge have been studied. In any part of the discharge the intensity of both the spectral lines and the continuum depends upon the peak current and the inductance in the discharge circuit, while at a particular current and inductance the intensity is found to be largest in the cathode region, somewhat smaller in the central region, and smallest in the anode region of the discharge. Patterns from the central region exhibit less violent fluctuations than those from either of the other two regions. At currents above about 30 kamp and an inductance of only 1.8 µh the contribution of the continuum to the total intensity is so large that the net line intensity either increased only slightly or actually decreased with increasing currents for all except the C III 4647-A line. Although they are well defined, the intensity differences from one region to another are not as large as might be expected in view of the large vapor particle velocities believed to exist in the discharge. The effect of the design of the spark chamber on the character of the discharge is discussed briefly.