

Discharges in Electrodeless Vacuum- Tubes. 513 



The rate of change of current will be greatest (either a maxi- 

 mum or a minimum) when 



bt=—y, 7r—y, 27T — 7, &c. 



Obviously bt cannot equal —7, so that the rate of change 

 of current is greatest for values 77 — 7, 2ir—y, &c. ; or at 

 points //, 1? ^ 2 , ^3, &c. in the curve (fig. 9), and EF = 7. If 



Fig. 9. 



V -~t. 

 Dotted curves are values of the exponential ^ e 2L 



M 1? M 2 , M 3 , M 4 are the maximum values of the current. fi v n 2 , u 3 are 

 the points where the rate of change of current is greatest. 



the oscillations are to be very rapid KR 2 must be negligible 

 compared to 4L ; in which case 



also 



tan y ='By/j£s 



