Homogeneous Corpuscular Radiation. 

 Table II. 



343 



Distance apart of 



aluminium window 



and radiator R 2 . 



Ratio of capacity of system in 

 thi9 position to that in which 

 the surfaces are 3 cm, apart. 



"05 cm 



1-427 

 1-291 

 1-200 

 1137 

 1-097 

 1069 

 1-050 

 1033 

 1-023 

 1018 

 1012 

 1004 

 1002 

 TOO 



•07 cm 



•10 cm. . 



•15cm 



•20 cm 



•25 cm 



•30 cm. . 



•40 cm 



'50 cm 



•60 cm 



•80 cm 



1'50 cm 



200 cm 



300 cm 





capacity of the system against the distance apart of the 

 aluminium window and the radiator R 2 , the points were 

 found to lie upon a smooth curve, so that where necessary 

 intermediate values could be obtained by interpolation (see 

 PI. V. fio-. 4). With each new radiator R« this calibration 

 was repeated. 



When the radiation from R, passed into the ionization- 

 chamber I the ionization produced was due to the following 

 sources : — 



(a) The corpuscular radiation from the face of the tertiary 

 radiator upon which the Rontgen radiation from R x was 

 incident. 



(b) The corpuscular radiation from the interior surface of 

 the aluminium window through which the radiation passed. 



(c) The exciting Rontgen radiation from R x in its passage 

 across the space between the aluminium window and the 

 tertiary radiator R 2 . 



(d) The tertiary Rontgen radiation from the tertiary 

 radiator R 2 . 



(<?) The tertiary Rontgen radiation from the aluminium 

 window. 



From some results obtained during the investigation 

 upon the tertiary Rontgen radiation* it was evident that the 

 contribution of (d) and (e) would be small. It was, however, 

 tested for separately, and a correction made for it. 



During some early tests the effect of (Ji) was shown in 



* Sadler, Phil. Mag. July 1909. 



