LB 170048 Nickel Foil Consistency Check

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The activity of Nickel foils from the front and rear of the sample container were compared. Below is a table of pictures and information from ROOT sessions. For each of these, the spectrum was weighted by the inverse of the mass. For the front foil the mass was 1.3310g and for the rear foil the mass was 1.2196g. If the background subtraction is negative, take the mean of the two numbers.

To find the error in the background, the expanded window's background was subtracted from the original window's background. The signal was found by integrating the gaussian over the original window with an adjusted amplitude, which has been background subtracted and fed into mathematica.


5/23/17 5/26/17 5/29/17 5/30/17
Original Window 170048 003 FrontFoil Pos70 5 23 17.png 170048 003 FrontFoil 5 26 17.png 170048 003 FrontFoil Pos10 5 29 17.png 170048 003 FrontFoil Pos10 5 30 17.png
Expanded Window 170048 003 FrontFoil Pos70 ExpWindow 5 23 17.png 170048 003 FrontFoil Pos30 5 26 17 ExpWindow.png 170048 003 FrontFoil Pos10 5 29 17 ExpWindow.png 170048 003 FrontFoil Pos10 5 30 17 ExpWindow.png
Original Background (Integrated) 388.8 +/- 63.2 297.2 +/- 72.8 1145.6 +/- 115.2 1024 +/- 92
Expanded Window Background (Integrated) 307.9 +/- 35.8 411.80 +/- 42.90 1058 +/- 68 681.4 +/- 53.4
BG Average 348.35 +/- 72.64 354.5 +/- 84.5 1101.8 +/- 133.77 852.7 +/- 106.37
Integral of Original Window 1.312e^4 1.777e^4 2.479e^4 1.69e^4
Integral of Expanded Window 1.32e^4 1.792e^4 2.506e^4 1.704e^4
Integral Difference 80 150 270 140
Counts 13120 +/- 80 17770 +/- 150 24790 +/- 270 16900 +/- 140
Signal (BG subtracted Counts) 12771.65 +/- 108.06 17415.5 +/- 172.16 23688.2 +/- 301.32 16047.3 +/- 175.78
Efficiency 8.9e^-5 +/- 1.8e^-6 4.22e^-4 +/- 4.671e^-6 0.0031 +/- 3.71e^-5 0.0031 +/- 3.71e^-5
.dat file entry 13.0745843 +/- 0.0211725 11.82996708 +/- 0.0148404 10.14076001 +/- 0.0174652 9.751499466 +/- 0.0162239


The information for the rear foil is shown below

5/23/17 5/26/17 5/29/17 5/30/17
Original Window 170048 004 RearFoil 5 23 17.png 170048 004 RearFoil Pos30 5 26 17.png 170048 004 RearFoil Pos10 5 29 17.png 170048 004 RearFoil Pos10 5 30 17.png
Expanded Window 170048 004 RearFoil Pos70 5 23 17 Expanded.png 170048 004 RearFoil Pos30 5 26 17 Expanded.png 170048 004 RearFoil Pos10 5 29 17 Expanded.png 170048 004 RearFoil Pos10 5 30 17 Expanded.png
Original Background (Integrated) 344.16 +/- 53.44 273.2 +/- 60.16 1164.8 +/- 105.6 718.32 +/- 72
Expanded Window Background (Integrated) 262.2 +/-31.5 386.5 +/- 39.5 889.7 +/- 61.3 488.3 +/- 43.3
BG Average 303.18 +/- 62.03 329.85 +/- 71.97 1027.25 +/- 122.10 603.31 +/- 84.02
Integral of Original Window 1.036e^4 1.369e^4 2.257e^4 1.257e^4
Integral of Expanded Window 1.042e^4 1.38e^4 2.278e^4 1.267e^4
Integral Difference 60 110 210 100
Counts 10360 +/- 60 13690 +/- 110 22570 +/- 210 12670 +/- 100
Signal (BG subtracted Counts) 10056.82 +/- 86.30 13360.15 +/- 131.45 21542.75 +/- 249.92 12066.69 +/- 130.61
Efficiency 8.9e^-5 +/- 1.8e^-6 4.22e^-4 +/- 4.671e^-6 0.0031 +/- 3.71e^-5 0.0031 +/- 3.71e^-5
.dat file entry 12.83634845 +/- 0.0219699 11.56523893 +/- 0.0148095 9.934640683 +/- 0.0166677 9.469395687 +/- 0.0161365

The plots for the half lives are shown below

170048 003 HL Plot.png

170048 004 HL Plot.png

Now we can find the initial activity of each of the foils. There is no time correction needed for 170048-003 as its first measurement is set to t = 0. So we can find the activity with

The activity of the front foil (170048-003) is 428347.47 +/- 6766.18 Hz

Now since the rear foil's time stamp has the initial measurement of the front foil as 0 on the t-axis, we shouldn't need to time correct this either.

The activity of the rear foil (170048-004) is 385325.23 +/- 6487.72 Hz


Note that these are not statistically the same, but the ratio between the activities of the front and rear nickel foil is 0.80 +/- 0.02

Note that 170048 was a 10% soil and selenium mixture. This means that there would be more soil in the aluminum cylinder to attenuate the beam. This could be a reason why the ratio isn't closer to 1.