224 



ISOTOPIC TRACERS AND NUCLEAR RADIATIONS [Chap. 7 



Isotope 

 Z A 



51 Sb 129 



Sb 1 " 

 Sb 1 " 



Sb 1 " 



52 Te< 118 



T e i is 



Te"» 



T e 120 



Te 121m 



Te 121 « 



Te 121 



Tei" 

 Tei" 

 T e i2< 

 Tei 26 



Class 



B 



A 



B 



D 

 B 



B 



Per cent 

 abundance 



Type of 

 radiation 



0.091 



2.49 

 0.89 

 4.63 

 7.01 



K, 



y. e~ 



Half-life 



4.2 hr 



I.T.. e-, y 



I.T.. y 



K, 



4.5 days 



143 days; 

 125 days 



Energy of radiation, Mev 



Particles 



0.2, 0.5(e-) 

 spect. 



5 X 10-8 

 sec 



17 days 



7-rays 



No 7(?) 



1.4 abs. Pb 



0.0365(?), 



0.082, 



0.0885, 



0.159, 



0.213 



spect. 



con v.; 



0.0820, 



0.0883, 



0.136, 



0.1573, 



0.2108 



spect. 



conv.; 



0.05 spect. 



conv., abs. 



Ag; 0.22 



abs. Pb 

 0.23 co- 



incid. abs. 



0.61 abs. 

 Pb; 0.615 



spect. 

 conv. 



Produced 

 by 



U-n, parent 



of Tei2» 

 Pu-n 

 U-n, parent 



of Te 132 

 U-n, parent 



of Te 1 " 

 Th-n 

 U-n, parent 



of Te"« 



Sb-d-? 

 Sb-d-Sn, 



parent of 



Sb 118 



(3.3 min) 

 Sb-d-4n, 



parent of 



Sb 119 

 Bi-«i 



Sn-a-n 



Sb-d-2n 



Sb-p-n 



Te 121m 

 (143 days) 

 I.T.. par- 

 ent of Te 121 



Sb-d-2n 



Sb-p-n 



Te 121m 

 (143 days, 

 5 X 10-* 

 sec) I.T. 



