TABLE 726.— ARTIFICIAL DISINTEGRATION 669 



When various materials are bombarded with the high-speed particles produced by one of the de- 

 vices given in Table. 718, disintegrations, or the building up of elements higher in the atomic 

 table, result. Some examples of these reactions are given in the table. 



Part 1. — Some values of the energy of artificial disintegration for different isotopes and 



for different reactions 227 



Part 2. — Photo-nuclear reactions, threshold values 



H 2 (7,n)H 1 2.20± .05 Mev Ca 40 (7,«)Ca 39 15.9 ± .4 Mev Cd 113 (7,n)Cd 112 6.44±.15Mev 



Be°(7,«)Be 8 1.63± .3 Fe M (7,«)Fe 53 13.8 ± .2 Sn 11B (7,»)Sn 118 6.51± .15 



Li 7 (7,ft)He 8 9.8 ± .5 Mn B6 (7,n)Mn B4 10.15± .20 Sn 124 (7,«)Sn 123 8.50± .15 



C 12 (7,n)C 11 18.7 -l-l.O Cu 83 (7,n)Cu 02 10.9 ± .2 Sb 121 (7,«) Sb 120 9.25± .2 



N»*(7,«)N 13 10.65± .2 Cu 85 (7,«)Cu a4 10.2 ± .2 I 127 (7,n)I 128 9.3 ± .2 



Mg 24 (7,«)Mg 23 16.2 ± .3 Zn 84 (7,")Zn 83 11.80± .20 Vr^Hy^W 9.40± .10 



Mg 2B (7,f>)Na 2 * 11.5 +1.0 Zn 7 °*(7,«)Zn 89 9.20± .20 Nd 150 (7.n)Nd 149 7.40± .20 



Mg 28 (7,/')Na 25 14.0 -t-1.0 Br 7B (7,>0Br 78 10.7 ± .20 Ta 181 (7.«)Ta 180 7.7 ± .2 



Al 27 (7,n)Al 28 14.0 -+- .4 Br 81 (7,n)Br s0 10.2 ± .20 Au 197 (7,w)Au 19 « 8.00± .15 



Si 28 (7,n)Si 27 16.8 -+- .4 Zr 90 (7,n)Zr 89 12.48± .15 Hg 201 (7.»«)Hg 200 6.25± .20 



P 81 (7,n)P 30 12.35-t- .2 Zr B1 (7,n)Zr 90 7.20± .40 T1 205 (7,")T1 201 7.38± .15 



S 32 (7«)S al 14 8 -t- .4 Mo B2 (7,n)Mo 91 13.28± .15 Pb 207 (7,n) Pb 208 6.85± .20 



K 89 (7,n)K 38 13.2 + .2 Mo 97 (7,n)Mo 98 7.10± .30 Bi 209 (7,")Bi- , o 8 7.45± .2 



228 McElhinney, J., Hanson, A. O., Becker, R. A., Duffield, R. B., and Diven, B. C, Phys. Rev., vol. 75, 

 p. 542, 1949. 



SMITHSONIAN PHYSICAL TABLES 



