644 



ISOTOPIC TRACERS AND NUCLEAR RADIATIONS 



Average energy, of recoil particles, 351 

 Average excitation potential, 50, 78-80 



B 



Background correction, for ■ coincidence 

 counting, 325-326 



for counters, 317, 321-325, 362 



for ionization chambers, 355-356 

 Backscattering, of beta particles, 375-376 

 Beam extraction, in betatrons, 490-491 



in cyclotrons, 470-478 

 Beam oscillations, in betatrons, 491 



in cyclotrons, 481-482 

 Beta counters, 305-306, 315, 361-364, 372- 

 378 

 {See also Counters) 

 Beta-counter geometry, 316 

 Beta decay, 11, 63-68, 155, 159, 163-164 



matrix element in, 64 



mean life for, 64, 66 



probability for, 64 



selection rules for, 66-67 

 Beta emission, 3-7 

 Beta particles, 49-75 



absorption of, 51, 56-61 



absorption coefficient for, 58 

 of aluminum, 72-75 



absorption curve of, 59-61 



average energy of, 70-71 



energy loss, by ionization, 51-53 

 by radiation, 53-54 



energy spectrum of, 364 



ionization by, 54-55, 406 



maximum energy of, 65 



properties of, 49 



range, in aluminum, 56, 59-61 

 in tissue, 416 

 in water, 59-61 



range-energy relation of, 51, 56, 61 



scattering of, 61-63 

 multiple, 62 



standards for, 361-378 



stopping cross section for, 52 



stopping formula for, 51, 53-54 



stopping power for, 55 

 Betatron, construction of, 490 



flux conditions in, 489 



magnetic field of, 492 

 Bias energy, of neutron counters, 317-318 



Binding energy, of nuclei, 3-10, 149-151 



of orbital electrons, 35 



semiempirical formula for, 8-11 

 Bismuth, in biological tracer studies, 534, 

 549 



isotopes of, 21, 247-248 

 Blood, inorganic constituents of, 445 

 Bohr magneton, 12, 499 

 Boron, in biological tracer studies, 529 



isotopes of, 15, 187 

 (See also Neutrons) 

 Bragg curve of specific ionization, 89 

 Bragg-Gray principle, 370, 372 

 Bremsstraklung, 53, 55, 368, 373, 415 

 Bromine, in biological tracer studies, 531, 

 543, 547 



isotopes of, 15, 204-205 

 Bunching effect, in synchrotrons, 498 



Cadmium, isotopes of, 18, 219-220 

 neutron cross section of, 134, 147 

 Calcium, in biological tracer studies, 522, 

 542, 547 

 isotopes of, 15, 193 

 Capture cross section, for thermal neutrons, 



316 

 Carbon, in biological tracer studies, 514- 

 515, 542, 547 

 isotopes of, 15, 187-188 

 measurements of isotopes, 300-301, 515 

 neutron cross section of, 143-144 

 preparation of isotopes, 514 

 in radiotherapy, 541, 550 

 Cartesian diver, 271-272 

 Cathodes, of counters, 304, 313-317 



for electroplating of radioisotopes, 440 

 Cathodic deposition, in electrodeposition, 



441 

 Cavity ionization chamber, 349-351, 370- 



372, 407-408 

 Cerenkov radiation, 54 

 Charge detecting instruments, 351-355 

 Charged particle emission, 130 

 Charging system, for Van de Graaff gen- 

 erator, 472 

 Chemical reactions, of first order, 392-399 

 of higher order, 399-402 



