scholarly journals Deconvolution of Mono-Energetic and Multi-Lines Gamma-Ray Spectra Obtained with NaI(Tl) Scintillation Detectors Using Direct Matrix Inversion Method

2020 ◽  
Vol 39 (2) ◽  
pp. 104-115
Author(s):  
Mwingereza Kumwenda
Keyword(s):  
Response Function ◽  
Gamma Ray ◽  
Pulse Height ◽  
Inversion Method ◽  
Height Distribution ◽  
Deconvolution Method ◽  
Pulse Height Distribution ◽  
Simulation Based ◽  
Energy Gamma ◽  
Matrix Inversion Method

Performance of a NaI(Tl) scintillation detector based on the gamma-ray spectroscopy system is not satisfactory in retaining its original peak (which is delta like function) of various gamma ray spectrum. The method of achieving precise peak for the various gamma ray was conducted by converting the observed pulse-height distribution of the NaI(Tl) detector to a true photon spectrum. This method is obtained experimentally with the help of an inverse matrix deconvolution method. The method is based on response matrix generated by the Monte Carlo simulation based on Geant4 package of mono-energy gamma-ray photon ranging from 0.050 to 2.04 MeV in the interval of 10 keV. The comparison of the measured and simulated response function was also performed in order to authenticate the simulation response function. Good agreement was observed around the photo-peak region of the spectrum, but slight deviation was observed at low energy region especially below 0.2 MeV. The Compton backscattering and Compton continuum counts was significantly transferred into the corresponding photo-peak and consequently the peak to total(P/T) ratio was improved. The P/T ratio results obtained after application of the deconvolution method taken with three calibration sources with gamma-ray’s energies of 81 keV, 303 keV and 356 keV (for 133Ba), 662 keV (for 137Cs), 1173 keV and 1333keV (for 60Co), were improved from(to) 0.50(0.90), 0.40(0.83), 0.57(0.93), 0.31(0.92), 0.18(0.84) and 0.15(0.83), respectively.

scholarly journals Unfolding Low-Energy Gamma-Ray Spectrum Obtained with NaI(Tl) in Air Using Matrix Inversion Method

2010 ◽  
Vol 2 (2) ◽  
pp. 221-226 ◽  
Author(s):  
M. S. Rahman ◽  
G. Cho
Keyword(s):  
Response Function ◽  
Gamma Ray ◽  
Matrix Inversion ◽  
Low Energy ◽  
Inversion Method ◽  
Compton Continuum ◽  
Small Peak ◽  
Continuum Region ◽  
Energy Gamma ◽  
Matrix Inversion Method

Matrix inversion method is presented to unfold the gamma-ray spectrum obtained with an NaI(Tl) detector using several standard gamma-ray sources. The method is based on response matrix generated by Monte Carlo simulation of mono-energy gamma-ray photon ranging from 10 keV to 1 MeV in step of 10 keV. The comparison of the measured and simulated response function was also performed in order to validate the simulation response function. Good agreement was achieved around the photo-peak region of the spectrum, but slight deviation was observed at low energy region especially at Compton continuum region. The Compton continuum count was significantly transferred into the corresponding photo-peak and consequently the peak to background ratio was improved substantially by the application of the unfolding method. Therefore, small peak can be identified and analyzed that would otherwise be lost in the background.  Keywords: Gamma-ray spectrum; Unfold; NaI(Tl). © 2010 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved. DOI: 10.3329/jsr.v2i2.4372              J. Sci. Res. 2 (2), 221-226 (2010) 

THE PULSE HEIGHT DISTRIBUTION FROM A SODIUM IODIDE SINGLE CRYSTAL SCINTILLATION COUNTER AND THE MEASUREMENT OF GAMMA RAY FLUXES

1955 ◽  
Vol 33 (5) ◽  
pp. 209-218 ◽  
Author(s):  
G. M. Griffiths
Keyword(s):  
Single Crystal ◽  
Sodium Iodide ◽  
Gamma Ray ◽  
Scintillation Counter ◽  
Pulse Height ◽  
Height Distribution ◽  
Pulse Height Distribution ◽  
Electron Multiplication ◽  
Secondary Interactions ◽  
Bias Level

The theory of the interaction of gamma rays with a single crystal of sodium iodide is described and a comparison made between the pulse height distributions, calculated on the basis of primary interactions only, together with the broadening due to the statistics of light production and electron multiplication, and the experimentally measured distributions. The differences are qualitatively accounted for on the basis of secondary interactions, bremsstrahlung, and wall effects. The absolute efficiency of a scintillation counter, calculated from the size and volume and energy corresponding to the bias level of the counting system, has been used to compute the intensity of gamma radiation from a standardized source of Co60 and from the reaction Li7(p, γ)Be8, the yield of which was known from previous work. Good agreement was obtained after allowance was made, experimentally, for the secondary interactions.

Development of the Detector Response Function Approach for the Library Least-Squares Analysis of Energy-Dispersive X-Ray Fluorescence Spectra

1978 ◽  
Vol 22 ◽  
pp. 317-323 ◽  
Author(s):  
L. Wielopolski ◽  
R. P. Gardner
Keyword(s):  
Least Squares ◽  
Response Function ◽  
Fluorescence Spectra ◽  
Pulse Height ◽  
Energy Dispersive ◽  
Analytical Models ◽  
Detector Response ◽  
Height Distribution ◽  
Pulse Height Distribution ◽  
X Ray

A procedure to obtain analytical models for the elemental X-ray pulse-height distribution libraries necessary in the library least-squares analysis of energy-dispersive x-ray fluorescence spectra is outlined. This is accomplished by first obtaining the response function of Si(Li) detectors for incident photons in the energy range of interest. Subsequently this response function is used to generate the desired elemental library standards for use in the least-squares analysis of spectra, or it can be used directly within a least-squares computer program, thus eliminating the large amount of computer storage required for the standards.

Energy-dependent dead-time correction in digital pulse processors applied to silicon drift detector's X-ray spectra

2018 ◽  
Vol 25 (2) ◽  
pp. 484-495 ◽  
Author(s):  
Suelen F. Barros ◽  
Vito R. Vanin ◽  
Alexandre A. Malafronte ◽  
Nora L. Maidana ◽  
Marcos N. Martins
Keyword(s):  
Dead Time ◽  
Pulse Height ◽  
Height Distribution ◽  
Pulse Height Distribution ◽  
Dead Time Correction ◽  
Time Model ◽  
X Ray ◽  
Digital Pulse ◽  
Analytical Correction ◽  
Energy Dependent

Dead-time effects in X-ray spectra taken with a digital pulse processor and a silicon drift detector were investigated when the number of events at the low-energy end of the spectrum was more than half of the total, at counting rates up to 56 kHz. It was found that dead-time losses in the spectra are energy dependent and an analytical correction for this effect, which takes into account pulse pile-up, is proposed. This and the usual models have been applied to experimental measurements, evaluating the dead-time fraction either from the calculations or using the value given by the detector acquisition system. The energy-dependent dead-time model proposed fits accurately the experimental energy spectra in the range of counting rates explored in this work. A selection chart of the simplest mathematical model able to correct the pulse-height distribution according to counting rate and energy spectrum characteristics is included.

THE RESOLUTION CORRECTION IN THE SCINTILLATION SPECTROMETRY OF CONTINUOUS X RAYS

1958 ◽  
Vol 36 (12) ◽  
pp. 1624-1633 ◽  
Author(s):  
W. R. Dixon ◽  
J. H. Aitken
Keyword(s):  
Integral Equation ◽  
Numerical Analysis ◽  
Numerical Methods ◽  
Analytical Procedure ◽  
Pulse Height ◽  
Matrix Inversion ◽  
Height Distribution ◽  
X Rays ◽  
Smooth Solutions ◽  
Pulse Height Distribution

The problem of making resolution corrections in the scintillation spectrometry of continuous X rays is discussed. Analytical solutions are given to the integral equation which describes the effect of the statistical spread in pulse height. The practical necessity of making some kind of numerical analysis is pointed out. Difficulties with numerical methods arise from the fact that the observed pulse-height distribution cannot be defined precisely. As a result it is possible in practice only to find smooth "solutions". Additional difficulties arise if the numerical method is based on an invalid analytical procedure. For example matrix inversion is of doubtful value in making the resolution correction because there does not appear to be an inverse kernel for the integral equation in question.

Pulse height distribution of signals produced by exposing a thin GEM chamber to beta rays from an Sr-90 source

2014 ◽  
Vol 64 (9) ◽  
pp. 1281-1287
Author(s):  
B. J. Ahn ◽  
Y. J. Ha ◽  
C. H. Hahn ◽  
S. T. Park ◽  
C-Y Yi ◽  
...  
Keyword(s):  
Pulse Height ◽  
Height Distribution ◽  
Pulse Height Distribution

A Universal Detector for the X-Ray Spectrograph

1958 ◽  
Vol 2 ◽  
pp. 293-301 ◽  
Author(s):  
William R. Kiley
Keyword(s):  
Entire Range ◽  
Pulse Height ◽  
Height Distribution ◽  
Pulse Height Distribution ◽  
X Ray ◽  
Universal Detector ◽  
Detector Arrangement

AbstractA detector arrangement has been developed which will give nearly 100% efficiency over the entire range of wavelengths normally used in X-ray spectroscopy, including radiation from Mg Kα. A description of this counter is given and data obtained on pulse height distribution and pulse amplitudes will be discussed. Results obtained with typical specimens will be shown.

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