scholarly journals Calculation of NaI(Tl) detector full-energy peak efficiency using the efficiency transfer method for small radioactive cylindrical sources

2016 ◽  
Vol 31 (2) ◽  
pp. 150-158 ◽  
Author(s):  
Mona Gouda ◽  
Mohamed Badawi ◽  
Ahmed El-Khatib ◽  
Nancy Hussien ◽  
Mahmoud Abbas
Keyword(s):  
Path Length ◽  
Gamma Ray ◽  
Detection Efficiency ◽  
Analytical Calculation ◽  
Integral Form ◽  
Average Path Length ◽  
Active Volume ◽  
Housing Materials ◽  
Transfer Method ◽  
Efficiency Transfer Method

A direct analytical mathematical method is introduced to calculate the efficiency of gamma ray cylindrical detectors. The efficiency expression is deduced through a straightforward mathematical approach. The presented method is based on the accurate analytical calculation of the average path length covered by the photon within the detector's active volume, effective solid angle, and the efficiency transfer method in an integral form, so as to obtain a simple formula for the detection efficiency. In addition, the self-attenuation coefficient of the source matrix, the attenuation factors of the source container (with a radius smaller than the detector radius) and the detector housing materials are also treated by calculating the average path length within these materials. 152Eu aqueous radioactive sources covering the energy range from 121 keV to 1408 keV were used. Remarkable agreement between the measured and the calculated efficiencies was achieved, with discrepancies less than 6 %.

scholarly journals Calibration of NaI (Tl) cylindrical detector using axially shifted radioactive cylindrical sources

2019 ◽  
Vol 34 (4) ◽  
pp. 353-360
Author(s):  
Mona Gouda
Keyword(s):  
Theoretical Approach ◽  
Path Length ◽  
Detector System ◽  
Gamma Photon ◽  
Peak Efficiency ◽  
Energy Peak ◽  
Full Energy Peak Efficiency ◽  
Transfer Method ◽  
Efficiency Transfer Method ◽  
Good Agreement

In this article, the full energy peak efficiency of NaI detector using non-axial cylindrical sources is calculated by using a new efficient theoretical approach. This approach depends on using the efficiency transfer method and analytical calculations of the average path length of a gamma photon inside the source to the detector system. Measured efficiencies made by using 152Eu aqueous radioactive cylindrical sources with volumes 25 ml and 400 ml. Comparing calculated efficiencies to the measured one showed good agreement enabling the validation of this approach.

scholarly journals Improved STEREO simulation with a new gamma ray spectrum of excited gadolinium isotopes using FIFRELIN

2019 ◽  
Vol 55 (10) ◽  
Author(s):  
H. Almazán ◽  
L. Bernard ◽  
A. Blanchet ◽  
A. Bonhomme ◽  
C. Buck ◽  
...  
Keyword(s):  
Gamma Rays ◽  
Cross Sections ◽  
Neutron Capture ◽  
Gamma Ray ◽  
Detection Efficiency ◽  
Liquid Scintillator ◽  
Calibration Source ◽  
Active Volume ◽  
Capture Event ◽  
Excited Nuclei

Abstract. The STEREO experiment measures the electron antineutrino spectrum emitted in a research reactor using the inverse beta decay reaction on H nuclei in a gadolinium loaded liquid scintillator. The detection is based on a signal coincidence of a prompt positron and a delayed neutron capture event. The simulated response of the neutron capture on gadolinium is crucial for the comparison with data, in particular in the case of the detection efficiency. Among all stable isotopes, 155Gd and 157Gd have the highest cross sections for thermal neutron capture. The excited nuclei after the neutron capture emit gamma rays with a total energy of about 8MeV. The complex level schemes of 156Gd and 158Gd are a challenge for the modeling and prediction of the deexcitation spectrum, especially for compact detectors where gamma rays can escape the active volume. With a new description of the Gd (n,$ \gamma$γ) cascades obtained using the FIFRELIN code, the agreement between simulation and measurements with a neutron calibration source was significantly improved in the STEREO experiment. A database of ten millions of deexcitation cascades for each isotope has been generated and is now available for the user.

ANALISIS PERINGKAT TOP BRAND OJEK ONLINE MENGGUNAKAN JEJARING SOSIAL PERCAKAPAN TWITTER

2019 ◽  
Vol 24 (2) ◽  
pp. 88-104
Author(s):  
Ilham Aminudin ◽  
Dyah Anggraini
Keyword(s):  
Social Media ◽  
Social Network ◽  
Social Network Analysis ◽  
Network Analysis ◽  
Path Length ◽  
Average Path Length ◽  
Average Degree ◽  
Clustering Coefficient ◽  
R Programming

Banyak bisnis mulai muncul dengan melibatkan pengembangan teknologi internet. Salah satunya adalah bisnis di aplikasi berbasis penyedia layanan di bidang moda transportasi berbasis online yang ternyata dapat memberikan solusi dan menjawab berbagai kekhawatiran publik tentang layanan transportasi umum. Kemacetan lalu lintas di kota-kota besar dan ketegangan publik dengan keamanan transportasi umum diselesaikan dengan adanya aplikasi transportasi online seperti Grab dan Gojek yang memberikan kemudahan dan kenyamanan bagi penggunanya Penelitian ini dilakukan untuk menganalisa keaktifan percakapan brand jasa transportasi online di jejaring sosial Twitter berdasarkan properti jaringan. Penelitian dilakukan dengan dengan mengambil data dari percakapan pengguna di social media Twitter dengan cara crawling menggunakan Bahasa pemrograman R programming dan software R Studio dan pembuatan model jaringan dengan software Gephy. Setelah itu data dianalisis menggunakan metode social network analysis yang terdiri berdasarkan properti jaringan yaitu size, density, modularity, diameter, average degree, average path length, dan clustering coefficient dan nantinya hasil analisis akan dibandingkan dari setiap properti jaringan kedua brand jasa transportasi Online dan ditentukan strategi dalam meningkatkan dan mempertahankan keaktifan serta tingkat kehadiran brand jasa transportasi online, Grab dan Gojek.

SCALE-FREE AND SMALL-WORLD PROPERTIES OF A SPECIAL HIERARCHICAL NETWORK

Fractals ◽  
2019 ◽  
Vol 27 (02) ◽  
pp. 1950010
Author(s):  
DAOHUA WANG ◽  
YUMEI XUE ◽  
QIAN ZHANG ◽  
MIN NIU
Keyword(s):  
Degree Distribution ◽  
Path Length ◽  
Small World ◽  
Average Path Length ◽  
Clustering Coefficient ◽  
Hierarchical Network ◽  
Scale Free

Many real systems behave similarly with scale-free and small-world structures. In this paper, we generate a special hierarchical network and based on the particular construction of the graph, we aim to present a study on some properties, such as the clustering coefficient, average path length and degree distribution of it, which shows the scale-free and small-world effects of this network.

scholarly journals A Complex Network Approach for Quantitative Characterization and Robustness Analysis of Sandstone Pore Network Structure

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Yuhao Hu ◽  
Guannan Liu ◽  
Feng Gao ◽  
Fengtian Yue ◽  
Tao Gao
Keyword(s):  
Pore Structure ◽  
Complex Network ◽  
Degree Distribution ◽  
Path Length ◽  
Robustness Analysis ◽  
Pore Network ◽  
Average Path Length ◽  
Clustering Coefficient ◽  
Random Disturbance ◽  
Pagerank Algorithm

The rational characterization and quantitative analysis of the complex internal pore structure of rock is the foundation to solve many underground engineering problems. In this paper, CT imaging technology is used to directly characterize the three-dimensional pore network topology of sandstone with different porosity. Then, in view of the problem, which is difficult to quantify the detailed topological structure of the sandstone pore networks in the previous study, the new complex network theory is used to characterize the pore structure. PageRank algorithm is based on the number of connections between targets as a measure index to rank the targets, so the network degree distribution, average path length, clustering coefficient, and robustness based on PageRank algorithm and permeability-related topological parameters are studied. The research shows that the degree distribution of sandstone pore network satisfies power law distribution, and it can be characterized by scale-free network model. The permeability of rock is inversely proportional to the average path length of sandstone network. The sandstone pore network has strong robustness to random disturbance, while a small number of pores with special topological properties play a key role in the macroscopic permeability of sandstone. This study attempts to provide a new perspective of quantifying the microstructure of the pore network of sandstone and revealing the microscopic structure mechanism of macroscopic permeability of pore rocks.

scholarly journals Urban Transit Network Properties Evaluation and Optimization Based on Complex Network Theory

2019 ◽  
Vol 11 (7) ◽  
pp. 2007 ◽  
Author(s):  
Guo-Ling Jia ◽  
Rong-Guo Ma ◽  
Zhi-Hua Hu
Keyword(s):  
Complex Network ◽  
Network Theory ◽  
Public Transportation ◽  
Path Length ◽  
Transportation Network ◽  
Average Path Length ◽  
Theory And Practice ◽  
Complex Network Theory ◽  
Public Transportation Network ◽  
Bus Network

Urban public transportation contributes greatly to sustainable urban development. An urban public transportation network is a complex system. It is meaningful for theory and practice to analyze the topological structure of an urban public transportation network and explore the spatial structure of an urban transportation network so as to mitigate and prevent traffic congestion and achieve sustainability. By examining the Xi’an bus network, the degree distribution, average path length, aggregation coefficient, and betweenness centrality of the bus station network were computed using models in complex network theory. The results show that the node degrees of the Xi’an bus network are unevenly distributed and present a polarization diagram with long average path length and high aggregation. A model based on betweenness and its solution method was developed to improve the public transportation network’s sustainability and discuss the possibility of optimizing the sustainability by network analyzing methods.

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