Page 268 - Radiochemistry and nuclear chemistry

252 Radiochemistry and Nuclear Chemistry

TABLE 9.1. Limits of detection for 71 elements in a thermal neutron flux of lOl7 n m "2 s "1 (1 h irradiation)
,, , , ,
Limit of detection Elements
Lug)
1-3 x 10 -6 Dy
4-9x10 -6 Mn
1-3 x 10 -5 Kr, Rh, In, Eu, Ho, Lu
4-9x 10 -5 V, Ag, Cs, Sm, Hf, Ir, Au
1-3 x 10 -4 Sc, Br, Y, Ba, W, Re, Os, U
4-9 x 10 -4 Na, AI, Cu, Ga, As, Sr, Pd, I, La, Er
1-3 x 10 -3 Co, Ge, Nb, Ru, Cd, Sb, Te, Xr Nd, Yb, Pt, Hg
4-9x 10 -3 Ar, Mo, Pr, Gd
1-3 x 10-2 Mg, CI, Ti, Zn, Se, Sn, Ce, Tm, Ta, Th
4- 9 x 10- 2 K, Ni, Rb
1-3 x 10 -l F, Ne, Ca, Cr, Zr, To
10- 30 Si, S, Fe

. ' I ' I ' I ' I ' I ' I ' I ' I ' I ' I
- /~ I=otopes observed ,
!0' -" ~ / ~ 22N" 85Sr 124Sb :
! ~'~'~ / I 47C" 86Rb 134Cs
" "-J ~ Detector NaI(TI) (3 in x 5 in) r~Fe eSZr 140Ba :
" ~ / eOco ,,.. ,4OLa -
107 E" ~ _ 66Zn 103Ru ..=
\
" IS
10 s
..I
UJ
Z
- ,o-.. i ,.o~. ;S,~b "
:3:: 10 5 i =
O : ~'487\ II | ilTsz ~ 1,z74
r : \"g \ II/'~4Sbl34c$ ! / ,OZS / : "
I,U - \\\it/f 6o~ I/ I I"r, :
Q. . / ~,il ! I ISZr I I ,4- I l 1292
r / -Ii. l?zJ,,~ll 7:,~, o I ,, II,,~~ .
k- 10 4 - / U~ll ":" ......... z. ~7 "
Z
:3 ::Detector:/ "~'J~ '''5"r' 1 /// ,Or ."
0 \" ~. III'~ f///..z .4OLo
(.) - Ge(Li)3e(Li) (20(20 cmcm 33,1111 mmmm deep)deep) -
io 3 - "~Jl~l r;,7~i / ?~s~' I ,6,, -
10 2 .=- Neutron exposure: Integrated flux of 2x10 TM neutrons cm -2 ~ .il II ---
" Absorber: 0.7 mm Cd plus 0.7 mm Pb -MI~ II =-
: Decay period: 54 days ",J
- Count interval: 3000 rain -.
101 , I ' I , I i I , I , I i I , I , I , I
0 100 200 300 400 500 600 700 800 900 10()0
CHANNEL NUMBER

FIG. 9.6. "y-spectrum of neutron-activated sea water. (From Cooper, Wogman, Palmer and Perkins.)