RADIATION AND THE CELLULAR SYNTHESIS OF PROTEIN 



77 



Table II 



A'irus 



Influenza A (infectivity) 



Newcastle Disease (infectivity) 



Shops papilloma (infectivity) 



Measles 



Southern bean mosaic virus 



Table III 



Enzyme 



Cell 



Diameter(m/x) 

 Dry Wet 



Diffusion distance in 

 angstroms 



STATISTICAL ANALYSIS OF RADIATION DATA 



If the idea of complete escape from ionization is to be used it is tirst 

 necessary to determine the nature of the distribution of ionization. If 

 the agent causing ionization is a fast electron the primary ionizations 

 are widely separated along the track, which is itself very much subject 

 to scattering. Thus there is every reason to treat the ionization pro- 

 duced by fast electrons, which includes the effects of gamma rays 

 which generate fast electrons, as being spread statistically throughout 

 any volume. The original tracks do not contribute regions of locally 

 high ionization in any way that matters much. The ionizations them- 

 selves are not wholly vuiderstood for solid or liquid material. If we apply 

 the results found for gasses to more dense material then the average 

 energy release at a primary ionization is 100 eV. There is a wide distri- 

 bution of values around this average, but it can be used as a basis for 

 statistical reasoning. We suppose that all the secondary ionizations 

 consequent on the primary process occur within a distance of a few 

 angstrom units from the primary ionization. This will not be true for 

 the more energetic secondary electrons, but it is true for those near to 

 the average. It is not a bad first approximation. Using this value, we 

 take the energy lost per cubic centimeter in the material bombarded as 

 a result of the radiation, express it in electron volts and divide by 100. 

 This then gives /, the number of clusters of ionization per unit volume, 



