139 



basis of action of radiation, 39 



determination of double coil 



structure, 120 



excitation by UV and ionizing 



radiation, 113, 114 



function in protein synthesis, 



114 



ratio of purine to pyrimidine, 



120 



role in protein synthesis, 109, 



110 



Organic molecules 



color changes, 41 



irradiation of rigid solutions, 



45 

 Oxidation reduction processes 



molecular excitation, 109 



Penetration phenomena 



of low energy particles, 3 



Penning ionization gauge 



measurement of excitation, 93 



Pepsin albumin 



correlation of "unfolding" and 

 radiation sensitivity, 116, 117 

 inactivation of surface film on 

 water, 110 



Phage 



deactivation by ultraviolet, 94 

 deactivation by X radiation, 95 

 reactivation by visible life, 94 



Phosphorescence 



measure of triplet- singlet 

 transitions in organic mole- 

 cules, 90, 91 



Photochemistry 



of bimolecular processes, 108, 

 109 



Photoelectric effect 



absorption coefficient, 19 



Photographic emulsions 



measurement of radiation 

 penetration, 2 

 reactions of fast carbon 

 nuclei, 20 



Photo-ionization, 83 



Photolysis 



of a^Oi to determine radical 

 pair yield in gamma irradiated 

 water, 66, 67 



Photons 



replacement of electric field 

 of electrons, 25 



Photo- oxidation 

 color changes, 4 1 



dissociation of organic mole- 

 cules, 1 10 



Photoreactivation 



bacteriophage, 122 

 of amines, 109 



rigid solutions of organic mole- 

 cules, 41 

 in biologic material, 120, 12 1 



Photostabilization 

 plastics, 102 



Photosynthesis 



interaction of pigments, 108 



Plastics 



photostabilization, 102 



Point heat theory 



application to radiation induced 

 inactivation, 1 1 1 



Polarization of crystal 



application of Landau's theory 

 to electron hydration, 45, 48 



Polonium 



RBE on haploid yeast, 20 



Polyatomic molecule 



internal conversion time, 78 



Positive ions 



effect on moving electron, 27 

 spatial distribution in water, 54, 

 55 



Predissociation 



from molecular decomposition, 

 77 



radiationless transition of en- 

 ergy, 76 



"Preferential" recombination 

 Brownian motion kinetics, 70 

 electrons and positive ions, 70 



Proportional counters 



determination of small energy 

 losses, 78 



elimination of noise level, 79, 

 80 



energy loss of protons, 77 

 measurement of ionization 

 fluctuation of delta rays, 77 



Prosthetic groups 



inactivation by irradiation, 114 



Proteins 



basis of action of radiation, 39 

 chemically available energy 

 states, 102 



denaturation induced by ionizing 

 radiation, 105, 106 

 dielectric properties, 73 

 effects of low energy electrons 

 on partial and total unfolding, 116 

 synthesis theory, 110 



Protons 



distribution of energy loss thru 



