Variation in the intensities of mercury spectrum lines with pressure of the vapor
The relative intensities of spectrum lines of Hg vapor in the d.c. arc and at a pressure of 10^(-3) mm in a high frequency electrodeless discharge have been measured for wave-lengths ranging from 7000 to 3000A. There is a decided increase in intensity, relative to the triplet line 5460, of the singlet members in the low pressure discharge, the sharp series showing the greatest increases. The relative intensity increases rapidly with ascending members of the series. Five new lines in the sharp singlet series were observed. Combination singlets appeared strong in the red in the low pressure discharge. The first members of the triplet series do not show much change but the higher members show an increasing intensity at low pressure. Combination lines also show decided increase in the low pressure discharge.
©1929 The American Physical Society. Received 15 December 1928. The authors wish to thank Professor I. S. Bowen, who initiated this line of investigation at this laboratory, for his constant interest in the work and his many helpful suggestions and criticisms. They also wish to thank Mr. W. C. Michels for his courtesy in setting his photographic development apparatus and microphotometer at their disposal.