A W thesis: Difference between revisions
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===898 keV Signal and Background Noise Table=== | |||
{| border="1" |cellpadding="20" cellspacing="0 | |||
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| Run # || Area of Signal || Area of Background || Signal to Noise Ratio | |||
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| 7203 || || || | |||
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| 7204 || || || | |||
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| 7235 || || || | |||
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| 7236 || || || | |||
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[[File:Run7236_Y88_1836_signal.png | 400 px]] | [[File:Run7236_Y88_1836_signal.png | 400 px]] | ||
===1836.1 keV Signal and Background Noise Table=== | |||
{| border="1" |cellpadding="20" cellspacing="0 | |||
|- | |||
| Run # || Area of Signal || Area of Background || Signal to Noise Ratio | |||
|- | |||
| 7203 || || || | |||
|- | |||
| 7204 || || || | |||
|- | |||
| 7235 || || || | |||
|- | |||
| 7236 || || || | |||
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|} | |||
=Ba-133 CAA= | =Ba-133 CAA= | ||
Revision as of 20:58, 4 August 2014
Introduction
Methods of determining atomic concentration in Material
Neutron Activation Analysis (NAA)
Inductively coupled plasma mass spectrometry(ICP-MS)
Inductively coupled plasma atomic emission spectroscopy(ICP-OES)
Atomic Absorption Spectrometry (multi-element AAS)
Particle-induced X-ray Emission (PIXE)
Another method, uses X-ray from a synchrotron light source and look at the de-excitation of atomic electrons to measure the atomic number. Reports are that they can measure pico-gram quantities.
table of detection limits -vs- Method
Coincidence Counting Setup
Y-88 CAA
Background subtraction
Do the fit:
get parameters for line
Then fill 1 histogram with line
Then subtract
TH1F *coin1=new TH1F("coin1","coin1",30,1800,1860);
ntuple->Draw("ADC7*0.604963-49.7001 >>coin1")
TH1F *lin1=new TH1F("lin1","line1",30,1800,1860);
for(int i=1800;i<1861;i++){
lin1->Fill(i,-2028+1.12*i)
}
TH1F *sub1=new TH1F("sub1","sub1",30,1800,1860);
sub1->Add(coin1,1);
sub1->Add(lin1,-1);
sub1->Draw();
A pdf of the Mathematica notebook used to calculate background area, gaussian area, and plot signal/noise vs. activity.
Changed integration limits and re-fit r7235 File:AW Background Noise custom2.pdf
All the ROOT fit parameters used to find the background and the resulting peaks. File:Y-88 Fit Log.pdf
898 keV Signal and Background Noise Table
| Run # | Area of Signal | Area of Background | Signal to Noise Ratio |
| 7203 | |||
| 7204 | |||
| 7235 | |||
| 7236 |
1836.1 keV Signal and Background Noise Table
| Run # | Area of Signal | Area of Background | Signal to Noise Ratio |
| 7203 | |||
| 7204 | |||
| 7235 | |||
| 7236 |
Ba-133 CAA
Useful commands
Converting CODA data file to ROOT
make sure the CODA and ROOT environmental variables are setup by source the following scripts
source ~/CODA/setup
source ~/ROOT/root/bin/thisroot.csh
Now change to the data subdirectory and execute the program to convert the data file to root
cd /data
~/CODA/CODAreader/ROOT_V5.30/V785V792/evio2nt -fr6994.dat > /dev/null
rename the file so it has the .root extension allowing ROOT to identify it in the browser
mv r6994 r6994.root
Calibration work
System's intrinsic err
Plot calibration parameters as a function of time
determine the variance of the parameters using several (>20) fits
Impact of higher order fits
Plot [math]\displaystyle{ E_{expected} - E_{fit} -vs- E_{expected} }[/math]
Variance comes from several fits,.
Compare uncertainty when fit is E-vs-Channe to Channel-vs-E
Probably should use %error for the weighting
Concentration measurement
A comparison of the measure concentrations using singles and coincidence counting