650 



ISOTOPIC TRACERS AND NUCLEAR RADIATIONS 



Nuclei, volume of, 148 

 Number-range curve, 90-91 

 n-unit, unit of dose, 414 



O 



"One-level" formula, 125-126 

 One-phase tracer systems, 395-397 

 Operating voltage, of counters, 310, 327 



of ionization chambers, 344 



of proportion counters, 341 

 Orbital oscillations in synchrotrons, 497-498 

 Oscillation damping in betatrons, 491 

 Oscillator strength, 82 

 Oxygen, in biological tracer studies, 517, 

 542, 547 



isotopes of, 15, 188-189 



Packing fraction, 7, 9-10 



of stable isotopes, 15-21 

 Pair production, 32, 36, 39-41, 409, 419 

 Paired sources, 322, 324 

 Phase oscillations in synchrotrons, 496-497 

 Phase stability, in cyclotrons, 479 



in synchrotrons, 493-494 

 Phases in metabolizing systems, 393-402 

 Phosphorus, in biological tracer studies, 

 518-519 



isotopes of, 15, 191 



in radiotherapy, 537-539, 550 

 Photoelectric effect, 32, 35-37 



in tissue, 420 

 Photoelectrons, in counters, 306 

 Photoemission, 542 



Photographic emulsion, action of charged 

 particles upon, 381-382 



for mass spectrographs, 293 



for radioautographs, 385-386 

 Physical constants, 499 

 Pocket exposure meters, 465 

 Poisson distribution curve, 165, 319 

 Polarization, of absorbers, 83 



of insulators, 346 



of resistors, 294 

 Positron, 49 



Potassium, in biological tracer studies, 

 521-522, 542, 547 



isotopes of, 15, 192-193 

 Potential barrier, 93-94, 127 



Potentiometer for recording ion current, 354 

 Preamplifiers, 328 

 Pressure Van de Graaff, 474-475 

 Primary ionization, 54-55 

 Probable error, 321-322, 363 

 in counting rate meters, 339 

 of emission rates, 368 

 Probability of fission, 149-151 

 Prompt neutrons, 155, 158-159 

 Proportional counters, 341-343 



for discrimination of radiations, 341 

 Protactinium series, 177-178 

 Protons, 76-113 



acceleration of, in cyclotrons, 476-477 



in the Van de Graaff generator, 472, 475 

 energy loss of, in aluminum, 105 

 in beryllium, 99-100 

 in boron, 101-102 

 in carbon, 101-102 

 in helium, 97-98 

 in hydrogen, 97-98 

 in lithium, 99-100 

 in nitrogen, 103-104 

 in oxygen, 103-104 

 properties of, 76 

 in radiotherapy, 541, 550 

 range of, in air, 109-111 

 in aluminum, 105 

 in beryllium, 99-100 

 in boron, 101-102 

 in carbon, 101-102 

 in copper, 112 

 in helium, 97-98 

 in hydrogen, 97-98 

 in lead, 113 

 in lithium, 99-100 

 in nitrogen, 103-104 

 in oxygen, 103-104 

 in paraffin, 106 

 R.B.E. of, 406, 452 

 standardization of, 378-379 

 stopping cross section for, 108 

 Pulse-mixing circuits, 337 

 Pulse shape, from counters, 328 

 Pycnometer, 263 



Quadrupole moment, electric, 13-14 

 of isotopes, 22-27 





