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UK DM project: radioactivity test results

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Fréjus data

sample (source) analysis U conc.
(ppb)
Th conc.
(ppb)
K conc.
(ppm)
comments
by method
Al + 4% Si F GES < 0.3(a) < 1.2(b) < 0.8 137Cs < 0.15 kru; 60Co < 0.15 kru
Altuglas F GES < 0.6(a) < 2.3(b) < 2.7 137Cs < 0.3 kru; 60Co < 0.4 kru
Brass (screws) F GES < 0.3(a) < 1.2(b) < 1.6 137Cs < 0.15 kru; 60Co < 0.3 kru
Capacitors (epoxy) F GES < 1.4(a) < 5(b) < 5.5 137Cs < 1.5 kru; 60Co < 3 kru
CsI (Na) F GES < 3(a) < 6(b) < 11 137Cs 370 kru; 60Co < 0.7 kru
Cu (OFHC) F GES < 0.4(a) < 1.4(b) < 1.6 137Cs < 0.3 kru; 60Co < 0.3 kru
Delrin F GES < 0.03(a) < 0.23(b) < 0.2 137Cs 0.09kru; 60Co 0.06kru
Epoxy F GES < 1.4(a) < 9(b) < 22 137Cs < 1.5 kru; 60Co < 3 kru
Fe F GES < 0.4(a) < 1.2(b) < 2.2 137Cs < 0.3 kru; 60Co < 3 kru
NaI(Tl) F GES 27(a) 23(b) 1100 137Cs 4 kru; 60Co 9kru
NE110 (plastic scintillator) F GES 2.7(a) < 5(b) < 5.5 137Cs < 0.6 kru; 60Co < 0.6 kru
Ni F GES < 3(a) < 12(b) < 22 137Cs < 3 kru; 60Co < 6 kru
Nylon F GES < 0.7(a) < 2.3(b) < 3 137Cs < 0.5 kru; 60Co < 0.3 kru
Pb F GES < 0.3(a) < 1.2(b) < 1.1 137Cs < 0.15 kru; 60Co < 0.15 kru
PTFE (Teflon) F GES < 0.7(a) < 2.3(b) < 2.2 137Cs < 0.3 kru; 60Co < 0.4 kru
Resistors F GES 68(a) 230(b) 430 137Cs 5 kru; 60Co < 1.5 kru
Sapphire F GES < 3(a) < 9(b) < 11 137Cs < 1.5 kru; 60Co < 2 kru
Si (monocrystalline) F GES < 1.4(a) < 4(b) < 5.5 137Cs < 0.7 kru; 60Co < 1.2 kru
Stainless steel F GES < 0.3(a) < 1.2(b) < 1.6 137Cs < 0.3 kru; 60Co 2.9kru
Ti (screws) F GES < 0.6(a) < 5(b) < 2.2 137Cs < 3 kru; 60Co < 4 kru
Analysts: Analysis methods:
F: Fréjus collaboration GES: Gamma Emission Spectroscopy

Notes:

(a): from 214Bi g count, U chain assumed in equilibrium.
(b): from 208Tl g count, Th chain assumed in equilibrium.

Other remarks:

ppm: parts per million by weight, = conc. × 106 ppb: parts per (US) billion by weight, = conc. × 109
ppt: parts per (US) trillion by weight, = conc. × 1012   errors: 0.035(10) (e.g.) means 0.035 ± 0.01 (1 s.)
1 kru = 103 decays/day/kg