Revision as of 18:23, 5 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

A_W_CAA_apparatus

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.

File:AW Background Noise.pdf

Changed integration limits and re-fit r7235 File:AW Background Noise custom2.pdf

File:AW Background Noise custom3.pdf

All the ROOT fit parameters used to find the background and the resulting peaks. File:Y-88 Fit Log.pdf File:Y-88 Fit Log 2.pdf

Integrating the gaussian of the HpGe detector signal. File:AW Gaussian Integral.pdf

898 keV Signal and Background Noise Table

Run #	Area of Signal	Area of Background	Signal to Noise Ratio
7203	130.17	120.59	1.08
7204	825.34	558.66	1.48
7235	194.38	60.23	3.23
7236	1429.75	436.93	3.27

1836.1 keV Signal and Background Noise Table

Run #	Area of Signal	Area of Background	Signal to Noise Ratio
7203	83.29	24.73	3.37
7204	944.58	101.68	9.29
7235	82.25	20.90	3.94
7236	1849.86	97.64	18.95

[math]T_{1/2}[/math]	Trig	Signal	BackG Subtracted	Fit Parameters					Signal Area	Noise Area	SNR
.98 [math]T_{1/2}[/math]	sing			[math]\mu=[/math] +/- dA	[math]\sigma=[/math]	B	B	B			5
.98 [math]T_{1/2}[/math]	coin			A +/- dA	C	C	C	C			6

Ba-133 CAA

BO-08-22-13

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

AW_ADC_7_Histogram

AW_ADC_3_Histogram

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

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

PAA_Research

@@ Line 136: / Line 136: @@
 | <math>T_{1/2}</math> || Trig || Signal || BackG Subtracted || colspan="5" | Fit Parameters || Signal Area || Noise Area || SNR
 |-
-|  rowspan="2" | .98 <math>T_{1/2}</math>|| sing || [[File:Run7022_Y88_898_rawsignal_fit.png | 100 px ]] || [[File:Run7022_Y88_898_signalsub_fit.png | 100 px ]]  || A +/- dA || B || B || B || B  || || || 5
+|  rowspan="2" | .98 <math>T_{1/2}</math>|| sing || [[File:Run7022_Y88_898_rawsignal_fit.png | 100 px ]] || [[File:Run7022_Y88_898_signalsub_fit.png | 100 px ]]  || <math>\mu=</math> +/- dA || <math>\sigma=</math> || B || B || B  || || || 5
 |-
 | coin ||[[File:Run7023_Y88_898_rawsignal_fit.png | 100 px ]]  ||  [[File:Run7023_Y88_898_signalsub_fit.png | 100 px ]] || A +/- dA || C || C || C || C || || || 6

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