190 



I SO TOPIC TRACERS AND NUCLEAR RADIATIONS 



[Chap. 7 



Isotope 

 Z A 



11 Na" 



N a 26 



12 Mg23 



Mg24 

 Mg26 

 Mg26 

 Mg« 



13 A126 

 A12« 



A127 

 A128 



A129 



14 Si2' 



Si 28 

 Si29 

 Si™ 

 Si31 



Class 



B 



Per cent 

 abundance 



A 

 A 



A 



78.60 

 10.11 

 11.29 



Type of 

 radiation 



p-, y 



100 



92.28 

 4.67 

 3.05 



/S". y 



fi-.y 



Half-life 



58. 2 sec; 

 60 sec; 

 62 sec 



1 1.6 sec 



10.2 min; 

 9.6 min 



8 sec; 

 7.3 sec 



6 sec; 

 6.3 sec 

 7.0 sec 



2.30 min; 

 2.4 min 



6.7 min 



4.9 sec 



170 min 



Energy of radiation, Mev 



Particles 



3.4 abs. Al; 

 2.8 abs. Al 



2.82 cl.ch. 



0.79(20 %), 



1.80(80%) 

 spect.; 

 1.8 cl.ch.; 

 coincid. 



2.99 cl.ch.; 

 1.8 abs. 



3.01 spect.; 



2.75 



coincid. 



abs.; 3.3 



cl.ch.; 3.0 



cl.ch.; 3.10 



abs. Al, 



coincid. 

 2.5 cl.ch. 



and abs. 



3.74 cl.ch.; 

 3.54 cl.ch. 



1.8 cl.ch. 



7-rays 



2.76, 2.89 

 cl.ch. pair; 

 coincid. 



abs. 



1.01, 0.84 

 spect., 

 coincid.; 

 0.64, 0.84, 

 1 .02 spect. 

 1.05 



(single 7) 

 cl.ch. 

 recoil 



1.80 abs. 

 sec. e~; 

 1.80 spect. 

 1.8 spect.; 

 2.1 cl.ch. 

 recoil 



No 



Produced 

 by 



Mg-y-p 

 Mg-n-p 

 A\-y-2p 



Na-i>-K 

 Mg-7-n 



Mg-d-p 

 Mg-n-7 

 A\-n-p 



Mg2s-/)-n 



Na-a-n 



Mg-p-n 



Mg26-£-n 



Mg-/>-7 



Al-7-n 



Mg-a-p 

 Al-d-p 



AI-K-7 



Si-n-p 

 Si-y-p 

 P-n-or 



Mg-a-p 

 Si-n-p 

 Si-y-p 

 P-y-2p 



Al-p-n 



Mg-a-n 



Si-7-n 



Si-d-p 

 Si-n-7 

 P-n-p 

 S-n-a 



I 



