ULTRA SOFT X-RAY MICROSCOPY 



0Ka(23.7 A) 







10 20 30 " 40 



Fig. 9. Pulse height distribution for 0-K(23.7 A) radiation obtained from an oxidized copper anode 

 at one kilovolt excitation and with a chromium filter as described in Fig. 8. 



Fig. 10. Photograph of a "plug-in" x-ray source designed as schematically shown in Fig. 5. 



In Figs. 10 and 11 are shown photographs 

 of the source and the camera, and in Fig. 12 

 is shown the complete instrument mounted 

 with its power supply. 



Measurement of the Microradiographic 

 Image 



The photographic method has been the 

 most successful of those proposed to date 



for quantitative ultrasoft x-ray microradio- 

 graphic analysis. It would be ideal if the 

 transmitted intensity could be measured di- 

 rectly, as, for example, by a proportional 

 counter, by microphotometry from a fluores- 

 cent screen image, or by the direct measure- 

 ment of the photo and Auger electrons emit- 

 ted by the sample by electron multiplier 

 techniques. However, a very high image in- 



685 



