338 



PHENOMENA, ATOMS, AND MOLECULES 



VI. ANALYSIS OF EXPERIMENTAL DATA ON ATOM EVAPORATION 



Fig. 8 gives the experimental data on atom evaporation. The apparent 

 (observed) concentration of adsorbed caesium, Oa, is plotted as a function 

 of i/T. For each curve \ia is constant and has the value indicated. The 

 values of Ga above 0.25 X 10^^ v^^ere determined by the 2-lilament method. 

 Below 0.30 X 10^^, Ga was determined by the direct flashing method. An 

 enlarged plot of the lower Ga data is also given. 



The equation chosen for analysis of the data is 



In Va = Aa- Ba/T, 



(6) 



where Aa and Ba were functions of 9 only. It has been shown theoretically' 

 that Aa consists of two parts such that 



where 



Aa = A+S, 



S^lnO+i/ii-O) -\n(i-e). 



(7) 

 (8) 



2.J 2.2 ZJ 



Fig. 8. Experimental data on atom evaporation. Observed concentration of caesium 



(o ^) as a function of i/T. 



The dependence of A and Ba on B remained to be determined by the ex- 

 periments. 



If this form of equation is applicable to the observed data, then 

 (In Va — 5) plotted as a function of i/T, at any value of Q, should give 



