646 



ISOTOPIC TRACERS AND NUCLEAR RADIATIONS 



Diffusion constant, 132-133 



Diffusion gradient, 263 



Diffusion length, 133 



Dilution method with isotopic tracers, 



390-392 

 Diode coincidence circuits, 335 

 Dipole moment, electric, 13, 44 



magnetic, 12-13, 44 

 Discriminator, 318 

 Discriminator circuits, 333 

 Disintegration constant in radioactivity, 



359 

 Disintegration rate, determination of, with 

 ionization chamber, 369-372 



of uranium, 359-361 

 Dispersion in mass spectrographs, 283, 285 

 Dispersion frequency, 79, 84, 85 

 Distribution of radioactivity in tissue, 381 

 Dosage rate, as a function of gamma ray 

 energy, 427 



tolerance levels of, 452 



for various isotopes, 426 

 Dose, by beta particles, 414-419 



by gamma rays, 422-431 



by Xa 24 in man, 428-431 



by radiations, 348 



units of, 403-406, 409-414 

 Dose calculations, 408-409 



for charged particles, 414-419 



for gamma rays, 422-431 

 Dosimetry, 350, 368, 403-437 

 Drift tubes, for accelerating ions, 474 

 Dry ashing, temperatures for, 447 



of tissue, 446-448 



Electrodeposition of radioisotopes, 438- 111 

 Electrolysis cells for electroplating radio- 

 isotopes, 439 

 Electrolysis current, 442-444 

 Electrolysis potential, 442-444 

 Electrolysis power supply, 442 

 Electrometer, 293, 368 



Lindemann, 352-353 



moving vane, 352-353 



vacuum tube, 353-354 



vibrating reed, 354-355 

 Electrometer circuit, 295 

 Electrometer tubes, 295, 296 



Electronic cross section, for gamma rays, 



33, 36, 38-39 

 Electrons, acceleration of, in betatrons, 489 



in synchrotrons, 493 

 Electroplating of radioisotopes, 438-444 

 Electroscope, 293, 352, 467 

 Electrostatic focusing, in cyclotrons, 480- 

 481 

 in the Van de Graaff generator, 474 

 Elements, biologically essential, 508-509 

 Elimination, of active substances in tissue, 

 431-434 

 of tagged substances, 395-399 

 Elimination curves of metabolizing systems, 



394 

 Emission, of gamma rays, 149, 155 



of neutrons, 149, 158 

 Energy absorbed, per ion pair (See Average 

 energy) 

 in tissue, 403-431 

 Energy distribution, of beta particles, 64-65 



Maxwellian, 129-131 

 Energy loss, of charged particles, 76-85 

 in fission by gamma rays, 157-158 

 by ionization, 51-54, 76-86 

 of protons, 97-105 

 by radiation, 53-54, 491, 496-498 



(See also Beta particles; Protons; 

 Deuterons; Alpha particles) 

 Energy-unit, unit of dose, 404, 413 

 Energy-velocity curves for protons, alpha 



particles, and mesons, 107 

 Equilibrium in chemical systems, 392 

 Equilibrium constant in electrodeposition, 



442 

 Equipment for handling radioisotopes, 455- 



459 

 Equivalent roentgen, 412 

 Errors in mass spectrometers, 298-299 

 Exponential processes in biological systems, 



392-399 

 Exposure of personnel to radiation, 450-453 

 Extra-hazardous radioisotopes, 450-453 

 Extrapolation ionization chamber, 351 



Falling drop method, 263, 267 

 Fast neutrons, interactions of, with nuclei, 

 128-130 

 measurement of, 378 



