# LB 170048 Nickel Foil Consistency Check

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.

The information for the rear foil is shown below

The plots for the half lives are shown below

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.