. Carnegie Institution of Washington publication. SPECTROPHOTOMETRY STUDY OF KATHODO-LUMINESCENCE. 139 ments on Sidot blende (Fig. 148) the conditions as regards leakage were more favorable and the current remained nearly constant. During the observations corresponding to Fig. 148 the deflection of the galvanometer varied from 32 for the highest voltmeter reading () to 37 for the lowest voltmeter reading (). In the experiments with willemite (Fig. 146) the galvanometer deflection ranged from 7 to 25; and in the experiments with cadmium sulphate the range was from 15 to 31. The results
. Carnegie Institution of Washington publication. SPECTROPHOTOMETRY STUDY OF KATHODO-LUMINESCENCE. 139 ments on Sidot blende (Fig. 148) the conditions as regards leakage were more favorable and the current remained nearly constant. During the observations corresponding to Fig. 148 the deflection of the galvanometer varied from 32 for the highest voltmeter reading () to 37 for the lowest voltmeter reading (). In the experiments with willemite (Fig. 146) the galvanometer deflection ranged from 7 to 25; and in the experiments with cadmium sulphate the range was from 15 to 31. The results obtained are plotted in Figs. 145 to 148 and are further discussed below. CdSOi-\-xMnSOi.—Tliis substance was prepared by C. W. Waggoner, who has determined its decay curve when excited by the iron Excited by kathode rays it gave an intense yellow fluorescence, with scarcely observable phosphorescence. Close inspection of the powder showed occasional grains. e* o Fig- 145- CdSO* +*MnS04. The curves to the left show the relation between discharge potential and intensity for different wave-lengths. Curves / and // show the luminescence spectra for discharge potentials of 11,600 volts and 6,700 volts respectively. Curves /// and IV show, to a larger scale, the luminescence spectra excited by ultra-violet light and Roentgen rays respectivelj'. which glowed with an orange or red light. At the end of our experiments, after the powder had been bombarded by the kathode rays for about 10 hours, the surface was found to have acquired a ruddy brown discoloration. Upon standing for several months the powder scarcely responded at all to excitation by the iron spark, but recovered its activity after heating. Inspection of curves / and II, Fig. 145, shows that the form of the fluo- rescence spectrum is independent of the discharge potential, and therefore of the velocity of the kathode rays, since it is clear that one of these curves might be obtained from the other merely by changi
Size: 1721px × 1452px
Photo credit: © Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthorcarnegie, bookcentury1900, bookdecade1910, bookyear1912
