View source for LB Feb 2017 Energy Efficiency Calculations

==Theoretical Activities==


Na-22, 9.427micro Ci on July 1, 2008, half life 2.602 +/- 0.002 years, 99.937% for 1274.52 and 178.8 for 511 line , activity in March 31, 2016 =1.196micro Ci
:= <math>\left (0.99937 \right )\left ( 1.196 \times 10^{-6} \mbox{Ci} \right) \left (\frac{ (3.7 \times 10^{10} \mbox{Hz}}{\mbox{Ci}} \right)= 44,224 Hz </math> for the 1274 line

:= <math>\left (1.788 \right )\left ( 1.196 \times 10^{-6} \mbox{Ci} \right) \left (\frac{ (3.7 \times 10^{10} \mbox{Hz}}{\mbox{Ci}} \right)=  79122.6 Hz </math> for the 511 line

Cs-137, 661.660 line, 85.21% * 1.066micro Ci on July 1, 2008, half life 30.0 +/- 0.2 yrs, March 31, 2016 activity = 0.891micro Ci expected rate for 661 line 

:= <math>\left (0.8521 \right )\left ( 0.891 \times 10^{-6} \mbox{Ci} \right) \left (\frac{ (3.7 \times 10^{10} \mbox{Hz}}{\mbox{Ci}} \right)= 28091.2 Hz </math>

Mn-54, 11.77 microCi  on July 1, 2008, half life =312.20 +/- 0.07 days, 99.975% intensity on 834.826 , March 31, 2016 activity =0.02328micro Ci

:= <math>\left (0.99975 \right )\left ( 0.02328 \times 10^{-6} \mbox{Ci} \right) \left (\frac{ (3.7 \times 10^{10} \mbox{Hz}}{\mbox{Ci}} \right)=  861.1 Hz </math> for the 834 line


Co-60, 10.42micro Ci July 1, 2008, half life 5.271 +/- 0.001 years, 99.0 % for 1173.237 and 99.9824 % for 1332.501, March 31, 2016 activity=3.759micro Ci


:= <math>\left (0.99 \right )\left ( 3.759 \times 10^{-6} \mbox{Ci} \right) \left (\frac{ (3.7 \times 10^{10} \mbox{Hz}}{\mbox{Ci}} \right)=  137692.17 Hz </math> for the 1173 line


:= <math>\left (0.999824 \right )\left ( 3.759 \times 10^{-6} \mbox{Ci} \right) \left (\frac{ (3.7 \times 10^{10} \mbox{Hz}}{\mbox{Ci}} \right)=  139058.52 Hz </math> for the 1332 line

Ba-133, 9.821 uCi on 04-15-07 with a half life of 10.51 years 62.05% for the 356 line,  

:= <math>\left (0.6205 \right )\left ( 5.15 \times 10^{-6} \mbox{Ci} \right) \left (\frac{ (3.7 \times 10^{10} \mbox{Hz}}{\mbox{Ci}} \right)=  118236.28 Hz </math> for the 356 keV line

==Actual Activites==

This is an example of the method that will be used to find the activities in the calibrated source's spectra

The line of interest in Cs-137 the 661.7 line. 


Using the program BackgroundSubtract.C in /data/IAC/Se/Feb_2017_Efficiency/Energy_Efficiency and the root command 


BackgroundSubtract("r5818.root","r5891.root",412,3369);

The 661.7 keV line can be seen 

[[File:Cs137 Activity.png|200px]]

Note that the range along the x-axis is [640:680] and the integral is 208.3.

Taking the ratio of the rate seen in the detector and the theoretical rate calculated above, one can arrive at a detector efficiency of 0.7%

The rest of the data is on the wiki page

[[LB_Efficiency_Plots_Feb_2017]]

==Energy Efficiencies==

Below is a table with the calculated efficiencies

 {| border="3"  cellpadding="5" cellspacing="0"
|  Run || Source || Energy (keV) || Expected Rate (Hz) ||ROOT Window || HpGe Rate (Hz) || HpGe X-Cool Detector Efficiency (%)   
|-
||r5818 || Cs-137 || 661.7 || 28091.2 || [640:680] ||  208.3 || 0.7
|-
|| r5871 || Ba-133 || 356 ||118236.28 || [340:376] || 150.6 || 0.13
|-
|}