CMSIUM-OXYGEN-SILVER PHOTOELECTRIC CELL 



357 



In all cases the recovery is easily interpreted as attendant upon a 

 diffusion of free caesium from the matrix to the surface film, furnishing 

 a sequence of states with increasing film thickness, and approaching 

 the initial state of each cell, but we can not estimate the quantitative 

 differences in film thickness from state to state on account of the 

 uncertain nature of the oxidation and diffusion processes. 



100 



CELL B-POSITION 2 

 0-INITIAL READING 

 • -AFTER RELEASING Oj 

 A- AFTER 68 HRS. AT ROOM 



TEMP, 

 x- AFTER 8.7 HRS. AT 75° C. 

 D- AFTER 5.0 HRS. AT 75° C. 

 A- AFTER 5.0 MINS. AT 200° C 

 ■ - AFTER 10 MINS. AT 200° C. 



7000 



8000 9000 



WAVELENGTH IN A 



10000 



Fig. 11 — Relative spectral response to equal energy for cell B, position 2. 



The extension of this sequence of states to those with film thicknesses 

 greater than that of the initial state was made by the deposition of 

 caesium upon the cathode surfaces of cells constructed as already 

 shown in Fig. 7. When the cell was shaken and the steel ball made 

 to break the glass bulb containing caesium, caesium vapor filled the 

 glass cylinder and diffused slowly through the orifice. Data on three 



