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UK DM project: radioactivity test results

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Borex/ino (Raghavan et al.) data

sample (source) analysis U conc.
(ppb)
Th conc.
(ppb)
K conc.
(ppm)
comments
by method
Acrylic  M? ? 0.001 0.001 0.01  
Glass (Schott)  M? ? 18 18 30  
PM tube  M? ? 59 170 750  
Pseudocumene  M?
 K?
?
TIMS
3 × 10-6
3 × 10-6
5 × 10-6
7 × 10-6
 
(R)
Pseudocumene (source I) K
K
TIMS
TIMS
2.6 × 10-6
7.1 × 10-5
1.2 × 10-5
1.4 × 10-4
  (F) feedstock
still residue
Pseudocumene (source II) K
K
K
TIMS
TIMS
TIMS
1.1 × 10-5
1.2 × 10-5
8.4 × 10-6
1.3 × 10-4
> 0
1.5 × 10-4
  (F) feedstock
still residue
distillate
Steel  M? ? 5 5 10  
Trimethyl borate (TMB) M FTA < 6.2 × 10-5 < 0.002   (M)
Trimethyl borate  M? ? < 3 × 10-6 < 10-6 < 10-4  
Trimethyl borate as supplied  K? TIMS ~ 3 × 10-5 ~ 10-5   (R) (1 scriptl evaporated)
Trimethyl borate, distilled  K? TIMS < 6 × 10-6 < 10-6   (R) (1 scriptl evaporated)
Trimethyl borate, distilled  K? TIMS ~ 5 × 10-7     (R) (100 scriptl evaporated)
Water (de-ionized)  M? ? < 0.01 < 0.01    

 

Analysts: Analysis methods:
K: W. R. Kelly (NBS) FTA: Fission Track Analysis
M: J. W. Mitchell (AT&T) TIMS: Thermal Ionization Mass Spectrometry

Notes:
Solid information on Borex has always been hard to come by; all the above values except those for TMB and those with (F), (M), or (R) in the `comments' column come from Campanella's Table 4 (see Data sources for references), in which the values for steel and PM tube alone are described as `measured values'; whether the others are sound expectations or merely inspired guesses is not apparent.

The lower TMB limits are in the text of Campanella's paper; the higher from Mitchell & Raghavan (M).

(R) values are from Raghaven, who also gives following goals:
Acrylic: 1 ppt U, Th; 1 ppb K Pseudocumene: 10-15 U, Th; 0.1 ppt K
TMB: 10-16 U,Th; 0.01 ppt K H2O: 0.1 ppt U, Th; 10 ppt K

(F) values are from Fassett & Kelly; I have used the sums of their tabulated extraction(s) and residue values, since their extractions appear to be incomplete.

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