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

Rahman, Md. Shakilur; Cho, G.

doi:10.3329/jsr.v2i2.4372

Cited by 5 publications

(3 citation statements)

References 11 publications

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“…With the continuing development of signal and system theory in conjunction with developing computer technology, convolution methods have been widely applied, and increasing attention has also been devoted to deconvolution methods [10][11][12]. Deconvolution is the inverse operation of convolution.…”

Section: Gaussian Deconvolution Methodsmentioning

confidence: 99%

An inversion decomposition method for better energy resolution of NaI(Tl) scintillation detectors based on a Gaussian response matrix

Yang

et al. 2016

NUCL SCI TECH

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NaI(Tl) scintillation detectors have been widely applied for gamma-ray spectrum measurements owing to advantages such as high detection efficiency and low price. However, the mitigation of the limited energy resolution of these detectors, which detracts from an accurate analysis of the instrument spectra obtained, remains a crucial need. Based on the physical properties and spectrum formation processes of NaI(Tl) scintillation detectors, the detector response to gamma photons with different energies is represented by photopeaks that are approximately Gaussian in shape with unique full-width-at-half-maximum (FWHM) values. The FWHM is established as a detector parameter based on resolution calibrations and is used in the construction of a general Gaussian response matrix, which is employed for the inverse decomposition of gamma spectra obtained from the detector. The Gold and Boosted Gold iterative algorithms are employed to accelerate the decomposition of the measured spectrum. Tests of the inverse decomposition method on multiple simulated overlapping peaks and on experimentally obtained U and Th radionuclide series spectra verify the practicability of the method, particularly in the low-energy region of the spectrum, providing for the accurate qualitative and quantitative analysis of radionuclides.

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Section: Gaussian Deconvolution Methodsmentioning

confidence: 99%

An inversion decomposition method for better energy resolution of NaI(Tl) scintillation detectors based on a Gaussian response matrix

Yang

et al. 2016

NUCL SCI TECH

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“…The response matrix gives the probability that a photon is detected. In order to obtain a response matrix 𝑅(𝐸, 𝐸 0 ) one needs to calculate the Peak-to-Total ratio (P/T) (Rahma and Cho, 2010;Almaz et al, 2007). To obtain the peak-to-total ratio, the mono-energetic gamma spectrum peak was fitted to the Gaussian functions, and the peak region was calculated by taking  96 .…”

Section: Peak To Total Ratiomentioning

confidence: 99%

Comparison of End-Point Energies of Bremsstrahlung Photons from 28- GHz ECR Ion Source in Three Measurement Locations

Kumwenda

2023

TJET

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Bremsstrahlung photons measurement show elevated energy emission beyond critical energy in 28-GHz ECR and its nature is not revealed. Thus, the aim of this study is to unveil the nature of high end-point energies at the three measurement locations. Bremsstrahlung photons from a 28-GHz ECR ion source were measured at Busan center of Korean Basic Science Institute (KBSI). The gamma-ray detection system consists of three round type NaI(Tl) scintillation detectors placed 62 cm radially from the beam axis at the three measurement locations namely injection, centre and extraction sides of an ECR ion source, and a NaI(Tl) scintillation detector placed at the view port for monitoring photon intensity along the beam axis. Such design of the experiment was based on the inner structure of the ECR ion source and the shape of the ECR plasma. Also, bremsstrahlung photons were measured by exchanging the detector positions for studying systematic uncertainties. Monte Carlo simulation based on the Geant4 package was performed to take geometrical acceptance and the energydependent detection efficiency into account due to large non-uniformity in the material budget. True bremsstrahlung energy spectra from the 28-GHz ECR ion source were extracted using an inverse matrix unfolding method. The measured high end-point energies at the three measurement locations were 1.68 MeV, 1.72 MeV and 2.04 MeV for the injection, centre and extraction sides, respectively. The high end-point energy values of the measured bremsstrahlung photons beyond the theoretical energy value of 1.33 MeV were found to be correlated with the structure of the ECR ion source and the shape of the ECR plasma. Furthermore, the high end-point energy values resulting from the bremsstrahlung photons measurements in the 28-GHz ECR plasma are due to the higher number of unconfined electrons arriving at the chamber wall easily, and producing higher bremsstrahlung photons. The unconfined electrons are the results of imperfect magnetic confinement that cause electrons to escape from the plasma volume.

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“…The approach used in this study is based on the matrix inversion method, which has been used in several previous studies (see e.g. [32,33]). The unfolding process is presented below and has been adapted from the work of Paulsen et al [33], who provided detailed mathematical justifications.…”

Section: Deconvolution Processmentioning

confidence: 99%

Development of a 4π detection system for the measurement of the shape of β spectra

Singh

Mougeot

Leblond

et al. 2023

Nuclear Instruments and Methods in Physics Research Section A:

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

Cited by 5 publications

References 11 publications

An inversion decomposition method for better energy resolution of NaI(Tl) scintillation detectors based on a Gaussian response matrix

An inversion decomposition method for better energy resolution of NaI(Tl) scintillation detectors based on a Gaussian response matrix

Comparison of End-Point Energies of Bremsstrahlung Photons from 28- GHz ECR Ion Source in Three Measurement Locations

Development of a 4π detection system for the measurement of the shape of β spectra

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