LB Feb 2017 Geometric Efficiency Calculations

Below are the theoretical calculations for the theoretical decay frequencies

Na-22, 10.19 uCi on July 15, 2013, half life 2.602 +/- 0.002 years, 99.937% for 1274.52 keV line and 178.8 for 511 keV line , activity in Feb 4, 2017 = 3.947 uCi

= [math]\displaystyle{ \left (0.99937 \right )\left ( 3.947 \times 10^{-6} \mbox{Ci} \right) \left (\frac{ (3.7 \times 10^{10} \mbox{Hz}}{\mbox{Ci}} \right)= 145,946 Hz }[/math] for the 1274 keV line

= [math]\displaystyle{ \left (1.788 \right )\left ( 3.947 \times 10^{-6} \mbox{Ci} \right) \left (\frac{ (3.7 \times 10^{10} \mbox{Hz}}{\mbox{Ci}} \right)= 261,117.732 Hz }[/math] for the 511 keV line

Now compute the expected rate for February 5, 2017.

The activity on Feb 5, 2017 is 3.944 uCi, so the expected rates for the 2 lines are

= [math]\displaystyle{ \left (0.99937 \right )\left ( 3.944 \times 10^{-6} \mbox{Ci} \right) \left (\frac{ (3.7 \times 10^{10} \mbox{Hz}}{\mbox{Ci}} \right)= 145,836 Hz }[/math] for the 1274 keV line

= [math]\displaystyle{ \left (1.788 \right )\left ( 3.944 \times 10^{-6} \mbox{Ci} \right) \left (\frac{ (3.7 \times 10^{10} \mbox{Hz}}{\mbox{Ci}} \right)= 260919.264 Hz }[/math] for the 511 keV line

Now compute the expected rate for February 9, 2017

The activity on Feb 9, 2017 is 3.933 uCi, so the expected rate for the 2 lines are

= [math]\displaystyle{ \left (0.99937 \right )\left ( 3.933 \times 10^{-6} \mbox{Ci} \right) \left (\frac{ (3.7 \times 10^{10} \mbox{Hz}}{\mbox{Ci}} \right)= 145,429.32 Hz }[/math] for the 1274 keV line

= [math]\displaystyle{ \left (1.788 \right )\left ( 3.933 \times 10^{-6} \mbox{Ci} \right) \left (\frac{ (3.7 \times 10^{10} \mbox{Hz}}{\mbox{Ci}} \right)= 260,191.55 Hz }[/math] for the 511 keV line

Now compute the expected rate for Feb 12, 2017

The activity on Feb 12, 2017 is 3.924 uCi, so the expected rate for the 2 lines are

Below is a table where the actual efficiency will be calculated for position R (farthest position).

Run	Source	Energy (keV)	Expected Rate (Hz)	HpGe Rate (Hz)	HpGe Det D Efficiency (%)
r5825	Na-22	511	79122.6	(480:540) (4.309-0.065=4.244)	0.005
r5826	Na-22	511	28091.2	(480:540)(1.105-0.02281=1.0821)	0.004
r5827	Na-22	511	861.1	(480:540)(0.04037-0.009123=0.031247)	0.004
r5829	Na-22	511	137692	(480:540)(3.686-0.01939=3.67)	0.003
r5830	Na-22	511	44224	(480:540) (1.073-0.0057=1.0673)	0.002
r5831	Na-22	511	139058.52	(480:540)(3.283-0.05702=3.22598)	0.002