Some Useful Information Concerning the results:
The Conversion factors for the primordial nuclides are given by: 1 Bq 238U/kg = 81 ppb U (81 x 10-9 gU/g) The 238U decay chain gammas used are: 226Ra: 186.1 keV
214Pb: 295.21 and 351.92 keV
214Bi: 609.31, 1120.29, 1764.49 and 2204.21 keV
The relationships are valid for any daughters in the 238U, 235U or 232Th chain only if the chain is in equilibrium. 1 Bq 232Th/kg = 246 ppb Th (246 x 10-9 gTh/g) The 232Th decay chain gammas used are: 212Pb: 238.63 and 300.09 keV
208Tl: 583.19 and 2614.53 keV,
228Ac: 911.21 keV
1 Bq 40K/kg = 32300 ppb K (32300 x 10-6 gK/g) The 40K decay chain gamma used is: 40K: 1460.83 keV
1 Bq 235U/kg = 1.76 ppm U (1.76 x 10-6 gU/g) The 235U decay chain gammas used are: 235U: 143.76, 163.33 and 205.31 keV
The measurements of the samples below take into account the background measurements. If a measurement is below the background then the upper bound shown is the 90% confidence limit.
SENSEI Measurements:




























Sample Description Manufacturer Mass (g) Live Time (days) Run Numbers Counting Dates
(if applicable)






















SENSEI G001 Aurubis copper,
Type C110		 610.5 g 12.917 19061106
19061704		 Jun 11, 2019 Results:
238U from 226Ra

238U from 234Th

235U

232Th

40K

137Cs

60Co
Comments
Copper Plate Plate is 4”x4”x1/4”


Jun 25, 2019 (mBq/kg) <0.14

<13.58

0.35 +- 0.43 <0.20

1.49 +- 1.85 <0.27

0.056 +- 0.086






(ppb or ppm) <0.01 ppb

<1.1 ppb

0.61 ppb +- 0.75 ppb <0.05 ppb

0.05 ppm +- 0.06 ppm














Results: 210Pb:
7Be:

54Mn

228Ac:
210Po:














(mBq/kg) 4568.00 +- 33810.00 <1.84

0.09 +- 0.11 <1.21

<9410.00
















(ppb or ppm) 0.37 ppm +- 2.74 ppm





<0.3 ppb

<0.76 ppm










SENSEI G002 Aurubis copper,
Type C101		 602.2 g 14.000 190717 Jul 17, 2019 Results:
238U from 226Ra

238U from 234Th

235U

232Th

40K

137Cs

60Co
Comments
Copper Plate Plate is 4”x4”x1/4”


Aug 1, 2019 (mBq/kg) 0.76 +- 0.46 <15.52

0.24 +- 0.41 <0.26

<1.66

<0.22

0.11 +- 0.08






(ppb or ppm) 0.06 ppb +- 0.04 ppb <1.26 ppb

0.42 ppb +- 0.73 ppb <0.06 ppb

<53.62 ppb
















Results: 210Pb:
7Be:

54Mn

228Ac:
210Po:














(mBq/kg) <53790.00

0.35 +- 2.23 <0.23

<0.95

<8695.00
















(ppb or ppm) <4.36 ppm







<0.23 ppb

<0.7 ppm










SENSEI G003 Aurubis copper,
Type C110		 601.9 g 7.542 190709 Jul 9, 2019 Results:
238U from 226Ra

238U from 234Th

235U

232Th

40K

137Cs

60Co
Comments
Copper Plate Plate is 4”x4”x1/4”


Jul 17, 2019 (mBq/kg) 5.63 +- 0.80 <14.73

<0.78

<0.54

<2.81

<0.20

<0.14



This plate was counted as G001, it was then etched and passivated following the PNNL method on 2019-07-04.



(ppb or ppm) 0.46 ppb +- 0.06 ppb <1.19 ppb

<1.37 ppb

<0.13 ppb

<90.76 ppb















Results: 210Pb:
7Be:

54Mn

228Ac:
210Po:













(mBq/kg) 56784.00 +- 38532.00 <1.96

0.10 +- 0.23 <0.88

<10370.00
















(ppb or ppm) 4.6 ppm +- 3.12 ppm





<0.22 ppb

<0.84 ppm










SENSEI G004 Aurubis copper,
Type C101		 601.9 g 7.583 190801
190806		 Aug 1, 2019 Results:
238U from 226Ra

238U from 234Th

235U

232Th

40K

137Cs

60Co
Comments
Copper Plate Plate is 4”x4”x1/4”


Aug 26, 2019 (mBq/kg) 8.97 +- 0.95 12.69 +- 14.32 0.80 +- 0.57 <0.36

<2.70

0.47 +- 0.29 0.05 +- 0.13

This plate was counted as G001 and G003. It has now been U/S cleaned on 20190726 U/S #1226



(ppb or ppm) 0.73 ppb +- 0.08 ppb 1.03 ppb +- 1.16 ppb 1.41 ppb +- 1.01 ppb <0.09 ppb

<87.21 ppb















Results: 210Pb:
7Be:

54Mn

228Ac:
210Po:













(mBq/kg) <62200.0

<4.64

<0.17

<1.01

<28500.00
















(ppb or ppm) <5.04 ppm







<0.25 ppb

<2.31 ppm










SENSEI G005 Aurubis copper, Type Unknown 2120.54 g 16.542 191219 Dec 19, 2019 Results:
238U from 226Ra

238U from 234Th

235U

232Th

40K

137Cs

60Co
Comments
Copper Block Plate is 2.5”x 2.5”x 2”


Jan 6, 2020 (mBq/kg) <0.033

1.34 +- 1.77 0.01 +- 0.09 <0.10

<0.85

<0.072

0.004 +- 0.021

This piece was cut at SNOLAB from a larger 6”x6”x2” plate



(ppb or ppm) <2.67 ppt

0.11 ppb +- 0.14 ppb 0.02 ppb +- 0.17 ppb <24.6 ppt

<27.46 ppb
















Results: 210Pb:
7Be:

54Mn

228Ac:
210Po:














(mBq/kg) <39.90

<0.83

<0.062

<0.31

<4347.00
















(ppb or ppm) <3.23 ppb







<76.26 ppt

<352.11 ppb










SENSEI G006 Aurubis copper, Type Unknown 2194.25 g 19.500 200106 Jan 6, 2020 Results:
238U from 226Ra

238U from 234Th

235U

232Th

40K

137Cs

60Co
Comments
Copper Block
(No Surface Milling)		 Plate is 2.5”x 2.5”x 2”


Jan 27, 2020 (mBq/kg) <0.019

2.28 +- 1.77 0.041 +- 0.085 <0.076

0.35 +- 0.57 0.034 +- 0.050 0.010 +- 0.021

This piece was cut at SNOLAB from a larger 6”x6”x2” plate



(ppb or ppm) <1.54 ppt

0.18 ppb +- 0.14 ppb 0.07 ppb +- 0.15 ppb <0.02 ppb

11.41 ppb +- 18.31 ppb














Results: 210Pb:
7Be:

54Mn

228Ac:
210Po:
58Co:












(mBq/kg) <41.37

<0.49

<0.065

<0.15

<2670.00

0.135 +- 0.044











(ppb or ppm) <3.35 ppb







<0.04 ppb

<216.27 ppb










In Progress and To Be Measured:




























Sample Description Manufacturer Mass (g) Live Time (days) Run Numbers Counting Dates
(if applicable)






















Next Sample




Results:
238U from 226Ra

238U from 234Th

235U

232Th

40K

137Cs

60Co
Comments






(mBq/kg)



























(ppb or ppm)





























Results: 210Pb:
7Be:

54Mn

228Ac:
210Po:














(mBq/kg)





























(ppb or ppm)